Patent Application
20180362435
This disclosure relates to routes of synthesis of acrylic acid and other α,β-unsaturated carboxylic acids, including catalytic methods.
The majority of industrially synthesized chemical compounds are prepared from a limited set of precursors, whose ultimate sources are primarily fossil fuels. As these reserves diminish, it would be beneficial to use a renewable resource, such as carbon dioxide, which is a non-toxic, abundant, and economical C1 synthetic unit. The coupling of carbon dioxide with other unsaturated molecules holds tremendous promise for the direct preparation of molecules currently prepared by traditional methods not involving CO2.
One could envision the direct preparation of acrylates and carboxylic acids through this method, when carbon dioxide is coupled with olefins. Currently, acrylic acid is produced by a two-stage oxidation of propylene. The production of acrylic acid directly from carbon dioxide and ethylene would represent a significant improvement due to the greater availability of ethylene and carbon dioxide versus propylene, the use of a renewable material (CO2) in the synthesis, and the replacement of the two-step oxygenation process currently being practiced.
Therefore, what is needed are improved methods for preparing acrylic acid and other α,β-unsaturated carboxylic acids, including catalytic methods.
This summary is provided to introduce various concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify required or essential features of the claimed subject matter nor is the summary intended to limit the scope of the claimed subject matter.
In an aspect, this disclosure provides processes, including catalytic processes, for producing α,β-unsaturated carboxylic acids or salts thereof utilizing a porous crosslinked polyphenoxide resin. Because the porous crosslinked polyphenoxide resin is insoluble and/or the reaction system is otherwise heterogeneous, these processes represent an improvement over homogeneous processes that result in poor yields and involve challenging separation and/or isolation procedures.
Conventional methods generally make isolation of the desired α,β-unsaturated carboxylic acid (e.g., acrylic acid) difficult. In contrast, the processes disclosed herein utilize a porous crosslinked polyphenoxide resin comprising associated metal cations, also referred to as simply a crosslinked polyphenolate or a crosslinked polyaryloxide resin, that generally provides a heterogeneous reaction mixture. When combined with a catalyst such as a nickel catalyst, ethylene and carbon dioxide can be coupled to form a metalalactone, and the porous crosslinked polyphenoxide resin can subsequently destabilize the metalalactone which eliminates a metal acrylate. By developing the disclosed heterogeneous system, there is now provided a distinct advantage in ease of separation of the desired product from the catalytic system. Moreover, the porous crosslinked polyphenoxide resins may result in surprisingly high yields of the desired α,β-unsaturated carboxylic acid, such as acrylic acid.
The porous crosslinked polyphenoxide resin may also be referred to as a co-catalyst, and typically has associated sodium or potassium ions. For example, the use of the heterogeneous, porous crosslinked sodium-appended cocatalyst is advantageous at least because [1] it provides a more facile means of separation the acrylate product from the catalyst system, because it is not soluble in the process diluent, [2] the polyphenoxide can be regenerated in a reactor setting by sodium base (e.g. NaOR or NaOH) treatment by hydroxyl deprotonation and/or by base (e.g. NaOR) absorption into the solid porous matrix, [3] it retains its robustness and structural integrity such that it does not degrade under the reaction conditions or regeneration conditions using sodium treatment e.g. NaOR or NaOH), and [4] its porous crosslinked structure allows for high sodium deposition density and facile sodium site access by incoming catalyst intermediates (such as metalalactones), as well as ease of regeneration.
According to an aspect, the crosslinked resin can be prepared by a templated polymerization process, which can provide its highly porous architecture with higher densities of sodium sites. Thus, in an aspect, disclosed herein is a process for forming a porous crosslinked polyphenoxide resin, the process comprising:
In a further aspect, there is provided a process for forming an α,β-unsaturated carboxylic acid or a salt thereof, the process comprising:
In an aspect, there is also provided a process for forming an α,β-unsaturated carboxylic acid or a salt thereof, the process comprising:
This summary and the following detailed description provide examples and are explanatory only of the invention. Accordingly, the foregoing summary and the following detailed description should not be considered to be restrictive. Additional features or variations thereof can be provided in addition to those set forth herein, such as for example, various feature combinations and sub-combinations of these described in the detailed description.
The FIGURE illustrates an embodiment or aspect of this disclosure, showing the use a porous crosslinked polyphenoxide resin stationary phase in a column configuration, in which formation of the acrylate coupling reaction of ethylene and CO2 to form a metalalactone such as a nickelalactone in a mobile phase can be effected, and the resulting nickelalactone destabilized by the metallated crosslinked polyphenoxide resin stationary phase to form an acrylate product. The particular crosslinked polyphenoxide resin illustrated in this FIGURE is merely representative of the numerous types of covalent linkages that typically exist in these types of resins.
To define more clearly the terms used herein, the following definitions are provided. Unless otherwise indicated, the following definitions are applicable to this disclosure. If a term is used in this disclosure but is not specifically defined herein, the definition from the IUPAC Compendium of Chemical Terminology, 2nd Ed (1997) can be applied, as long as that definition does not conflict with any other disclosure or definition applied herein, or render indefinite or non-enabled any claim to which that definition is applied. To the extent that any definition or usage provided by any document incorporated herein by reference conflicts with the definition or usage provided herein, the definition or usage provided herein controls.
While compositions and methods are described in terms of “comprising” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components or steps, unless stated otherwise.
The terms “a,” “an,” and “the” are intended to include plural alternatives, e.g., at least one. For instance, the disclosure of “a porous crosslinked polyphenoxide resin,” “a diluent,” “a catalyst,” and the like, is meant to encompass one, or mixtures or combinations of more than one, porous crosslinked polyphenoxide resin, diluent, catalyst, and the like, unless otherwise specified.
The terms “including”, “with”, and “having”, as used herein, are defined as comprising (i.e., open language), unless specified otherwise.
The term “hydrocarbon” refers to a compound containing only carbon and hydrogen. Other identifiers can be utilized to indicate the presence of particular groups in the hydrocarbon, for instance, a halogenated hydrocarbon indicates the presence of one or more halogen atoms replacing an equivalent number of hydrogen atoms in the hydrocarbon.
As used herein, the term “α,β-unsaturated carboxylic acid” and its derivatives refer to a carboxylic acid having a carbon atom of a carbon-carbon double bond attached to the carbonyl carbon atom (the carbon atom bearing the double bonded oxygen atom). Optionally, the α,β-unsaturated carboxylic acid can contain other functional groups, heteroatoms, or combinations thereof.
The terms “polyphenol”, “polyaromatic”, and “polyaryloxy” are generally used herein to describe a specific type of porous crosslinked polyphenol resin or polymer based upon the phenol-formaldehyde crosslinked resins and their analogs, in which the phenol or aromatic group and methylene moieties are part of an extended crosslinked network, rather than being solely pendant groups that are bonded to a polymeric backbone. Therefore, aromatic groups in the polymeric structure are hydroxylated, or hydroxymetallated in the anionic form, or otherwise functionalized with a group that will carry the negative charge in the porous crosslinked polyphenoxide resin, for example, thiolate, alkyl amide. Crosslinked networks that are prepared using various substituted phenols or polyhydroxyarene co-monomers also included in this definition. The term “phenolic resin” may be used to describe these materials as well. In their anionic form, the polyphenol resins are termed in a corresponding fashion as crosslinked polyphenoxide or polyaryloxide resins. If the context allows, the recitation of a polyphenol or polyaryloxy resin also encompasses the corresponding anionic (metallated) polyphenoxide or polyaryloxide resins.
The terms “polyhydroxyarene” or “polyhydroxidearene” are used herein to refer to a resin or polymer based upon the phenol-formaldehyde crosslinked resins and their analogs, in which the phenol-type monomer includes more than one hydroxyl group. Resorcinol (also termed, benzenediol or m-dihydroxybenzene) is a typical polyhydroxyarene, and in its anionic form may be referred to as resorcinoxide.
For any particular compound or group disclosed herein, any name or structure presented is intended to encompass all conformational isomers, regioisomers, stereoisomers, and mixtures thereof that can arise from a particular set of substituents, unless otherwise specified. The name or structure also encompasses all enantiomers, diastereomers, and other optical isomers (if there are any) whether in enantiomeric or racemic forms, as well as mixtures of stereoisomers, as would be recognized by a skilled artisan, unless otherwise specified. For example, a general reference to pentane includes n-pentane, 2-methyl-butane, and 2,2-dimethylpropane; and a general reference to a butyl group includes a n-butyl group, a sec-butyl group, an iso-butyl group, and a t-butyl group.
Various numerical ranges are disclosed herein. When Applicants disclose or claim a range of any type, Applicants' intent is to disclose or claim individually each possible number that such a range could reasonably encompass, including end points of the range as well as any sub-ranges and combinations of sub-ranges encompassed therein, unless otherwise specified. For example, by disclosing a temperature of from 70° C. to 80° C., Applicant's intent is to recite individually 70° C., 71° C., 72° C., 73° C., 74° C., 75° C., 76° C., 77° C., 78° C., 79° C., and 80° C., including any sub-ranges and combinations of sub-ranges encompassed therein, and these methods of describing such ranges are interchangeable. Moreover, all numerical end points of ranges disclosed herein are approximate, unless excluded by proviso. As a representative example, if Applicants state that one or more steps in the processes disclosed herein can be conducted at a temperature in a range from 10° C. to 75° C., this range should be interpreted as encompassing temperatures in a range from “about” 10° C. to “about” 75° C.
Values or ranges may be expressed herein as “about”, from “about” one particular value, and/or to “about” another particular value. When such values or ranges are expressed, other embodiments disclosed include the specific value recited, from the one particular value, and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that there are a number of values disclosed therein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. In another aspect, use of the term “about” means±20% of the stated value, ±15% of the stated value, ±10% of the stated value, ±5% of the stated value, or ±3% of the stated value.
Applicants reserve the right to proviso out or exclude any individual members of any such group of values or ranges, including any sub-ranges or combinations of sub-ranges within the group, that can be claimed according to a range or in any similar manner, if for any reason Applicants choose to claim less than the full measure of the disclosure, for example, to account for a reference that Applicants can be unaware of at the time of the filing of the application. Further, Applicants reserve the right to proviso out or exclude any individual substituents, analogs, compounds, ligands, structures, or groups thereof, or any members of a claimed group, if for any reason Applicants choose to claim less than the full measure of the disclosure, for example, to account for a reference or prior disclosure that Applicants can be unaware of at the time of the filing of the application.
The term “substituted” when used to describe a group, for example, when referring to a substituted analog of a particular group, is intended to describe the compound or group wherein any non-hydrogen moiety formally replaces hydrogen in that group or compound, and is intended to be non-limiting. A compound or group can also be referred to herein as “unsubstituted” or by equivalent terms such as “non-substituted,” which refers to the original group or compound. “Substituted” is intended to be non-limiting and include inorganic substituents or organic substituents as specified and as understood by one of ordinary skill in the art.
The terms “contact product,” “contacting,” and the like, are used herein to describe compositions and methods wherein the components are contacted together in any order, in any manner, and for any length of time, unless specified otherwise. For example, the components can be contacted by blending or mixing. Further, unless otherwise specified, the contacting of any component can occur in the presence or absence of any other component of the compositions and methods described herein. Combining additional materials or components can be done by any suitable method. Further, the term “contact product” includes mixtures, blends, solutions, slurries, reaction products, and the like, or combinations thereof. Although “contact product” can, and often does, include reaction products, it is not required for the respective components to react with one another. Similarly, “contacting” two or more components can result in a reaction product or a reaction mixture. Consequently, depending upon the circumstances, a “contact product” can be a mixture, a reaction mixture, or a reaction product.
Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the typical methods and materials are herein described.
The Abstract of this application is not intended to be used to construe the scope of the claims or to limit the scope of the subject matter that is disclosed herein, but rather to satisfy the requirements of 37 C.F.R. § 1.72(b), to enable the United States Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. Moreover, any headings that are employed herein are also not intended to be used to construe the scope of the claims or to limit the scope of the subject matter that is disclosed herein. Any use of the past tense to describe any example otherwise indicated as constructive or prophetic is not intended to reflect that the constructive or prophetic example has actually been carried out.
Those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments disclosed herein without materially departing from the novel teachings and advantages according to this disclosure. Accordingly, all such modifications and equivalents are intended to be included within the scope of this disclosure as defined in the following claims. Therefore, it is to be understood that resort can be had to various other aspects, embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to one of ordinary skill in the art without departing from the spirit of the present disclosure or the scope of the appended claims.
All publications and patents mentioned herein are incorporated herein by reference for the purpose of describing and disclosing, for example, the constructs and methodologies that are described in the publications, which might be used in connection with the presently described invention. The publications discussed throughout the text are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention.
The present disclosure is directed generally to methods for forming α,β-unsaturated carboxylic acids, or salts thereof. An illustrative example of a suitable α,β-unsaturated carboxylic acid is acrylic acid.
According to one aspect, this disclosure provides for the formation of an α,β-unsaturated carboxylic acids and salts thereof from metalalactones and porous crosslinked polyphenoxide resins. One example of the α,β-unsaturated carboxylic acid salt formation from exemplary metalalactones and porous crosslinked polyphenoxide resins is illustrated in Scheme 1, which provides for a nickel catalytic coupling reaction between an olefin and CO2 and formation of an acrylate. As explained herein, Scheme 1 is not limiting but is exemplary, and each reactant, catalyst, polymer, and product are provided for illustrative purposes.
In Scheme 1, a transition metal catalyst as disclosed herein is illustrated generally by a nickel(0) catalyst at compound 1, and the olefin disclosed herein, generally an α-olefin, is illustrated generally by ethylene. In the presence of the catalyst 1, the olefin couples with CO2 to form the metalalactone 2. Metalalactone 2 is destabilized by its interaction with a heterogenized Lewis acid, i.e. a porous crosslinked metallated polyphenoxide resin 3 (“MOW” in Scheme 1). While not intending to be bound by theory, the metallated crosslinked polyphenoxide resin 3 is thought to interact with metalalactone 2 in some way, for example to form an adduct of some type, such as one illustrated as intermediate 4. Reaction with the combined metallated crosslinked polyphenoxide resin 3 and metalalactone 2 (or intermediate of some type, represented generally as 4) then proceeds to eliminate or release the metal acrylate 6, for example from intermediate 4, possibly by way of the nickel-acrylate adduct 5. Ethylene displacement ultimately regenerates catalyst compound 1 and byproduct reacted polymer (here, crosslinked polyphenol resin, which is regenerated to the porous crosslinked polyphenoxide resin reactant, for example the metallated crosslinked polyphenoxide resin 3, upon its reaction with a metal-stabilized base such as hydroxide or alkoxide. The participation of a solvent such as a polar solvent and/or base in the elimination or release of the metal acrylate 6, is not fully understood at this time and may include direct participation in the mechanism or simply solvating an acrylate salt which is insoluble in the diluent. In other words, elimination of the metal acrylate from 4 occurs to regenerate catalyst compound 1 and byproduct reacted polymer (here, crosslinked polyphenol resin), which is regenerated to the porous crosslinked polyphenoxide resin reactant 3 upon its reaction with a metal-stabilized base (not shown in Scheme 1). In the presence of CO2, the ethylene-stabilized adduct 1 is converted to metalalactone 2.
One exemplary base illustrated in Scheme 1 is a hydroxide base, but a carbonate base, similar inorganic bases, and a wide range of other bases can be used, particularly metal-containing bases. Metal containing bases can include any basic inorganic metal compound or mixture of compounds that contain metal cations or cation sources, for example, alkali and alkaline earth metal compounds such as oxides, hydroxides, alkoxides, aryloxides, amides, alkyl amides, arylamides, and carbonates like calcium hydroxide. In an aspect, the reaction of Scheme 1 can be conducted using certain bases as disclosed, but if desired, other organic bases such as some alkoxide, aryloxide, amide, alkyl amide, arylamide bases, or the like can be excluded. Typically, the inorganic bases such as alkali metal hydroxides have been found to work well.
An aspect of this disclosure is the high porosity and high density of associated metal (e.g. sodium) sites that can be achieved with the polyphenoxide resin is prepared and crosslinked using a templating process. Therefore, in an aspect, in an aspect, disclosed herein is a templating process for forming a porous crosslinked polyphenoxide resin, the process comprising:
When prepared in this fashion, the porous crosslinked polyphenoxide resin can be mesoporous, having an average pore diameter from about 2 nm to about 50 nm. Alternatively, the porous crosslinked polyphenoxide resin can be macroporous, having an average pore diameter greater than about 50 nm. In another aspect, the porous crosslinked polyphenoxide resin can have an average pore diameter from about 50 nm to about 250 nm. These pore diameters can be adjusted by, for example, the size of the basic particulate template used in preparing the crosslinked resin, by the extent of crosslinking reaction when the phenol compound and formaldehyde are contacted with varying amounts of aqueous base and/or reaction times and polymerization conditions. Surface area, pore diameter, and pore volume were measured by Brunauer, Emmett and Teller (BET) technique with nitrogen gas used as the probe.
Generally, the porous crosslinked polyphenoxide resin and associated cations used in the processes disclosed herein can comprise (or consist essentially of, or consist of) an insoluble porous crosslinked polyphenoxide resin, a solvent-swellable porous crosslinked polyphenoxide resin, or a combination thereof. It is further contemplated that mixtures or combinations of two or more porous crosslinked polyphenoxide resins can be employed in certain aspects of the disclosure. Therefore, the “porous crosslinked polyphenoxide resin” is a polymeric material which comprises a multiply-charged polyanion, together with an equivalent amount of counter cations, and is used generally to refer to both insoluble materials and solvent-swellable materials.
In an aspect, the porous crosslinked polyphenoxide resin (and associated cations) can be used in the absence of an alkoxide or aryloxide base. Further, the reactions and processes disclosed herein can be conducted in the absence of an alkoxide, an aryloxide, an alkylamide, an arylamide, and/or substituted analogs thereof. That is, additional bases with their associated counter ions are not required to effect the processes disclosed herein.
According to an aspect, the porous crosslinked polyphenoxide resin and associated cations used in the processes can be used in the absence of a solid support. That is the porous crosslinked polyphenoxide resin can be used is its natural polymeric form without being bonded to or supported on any insoluble support, such as an inorganic oxide or mixed oxide material.
Accordingly, the terms crosslinked polyphenol resin and crosslinked polyphenoxide resin are used generally to include such crosslinked polyphenol or polyphenoxide resins as a phenol-formaldehyde resin, a polyhydroxyarene-formaldehyde resin (such as a resorcinol-formaldehyde resin), a polyhydroxyarene- and fluorophenol-formaldehyde resin (such as a resorcinol- and 2-fluorophenol-formaldehyde resin), or combinations thereof. In their deprotonated form, these porous crosslinked polyphenoxide resins comprise metal cations associated with the phenoxide-formaldehyde resin, a polyhydroxidearene-formaldehyde resin (such as a resorcinoxide-formaldehyde resin), a polyhydroxidearene- and fluorophenoxide-formaldehyde resin (such as a resorcinoxide- and 2-fluorophenoxide-formaldehyde resin), and the like, including combinations thereof.
Thus, one aspect of the disclosed process provides for using a porous crosslinked polyphenoxide resin that comprises, consists essentially of, or consists of a phenoxide-formaldehyde resin, a polyhydroxidearene-formaldehyde resin (such as a resorcinoxide-formaldehyde resin), a polyhydroxidearene- and fluorophenoxide-formaldehyde resin (such as a resorcinoxide- and 2-fluorophenoxide-formaldehyde resin), or combinations thereof. For example, these resins include but are not limited to a phenoxide-formaldehyde resin, a resorcinoxide-formaldehyde resin, a resorcinoxide- and 2-fluorophenoxide-formaldehyde resin, or any combinations thereof.
In an aspect, a variety of substituted phenols can be used to prepare the phenol-formaldehyde type of crosslinked resins. Examples include, but are not limited to, phenols that are substituted with at least one electron withdrawing group. When multiple electron withdrawing groups are present, the electron withdrawing groups can be the same or can be different. For example, the phenol can be substituted with fluorine in one or more than one position. The fluorine can be ortho to the phenol hydroxyl group or can be at other positions, and the phenol can be multiply substituted with an electron withdrawing group such as fluorine substituents. Bulky ortho substituents such as an ortho-t-butyl group can be used (that is, ortho-t-butyl phenol as a reactant), which can also provide the benefit of largely preventing carbonate formation.
These polymers that generally fall under the phenol-formaldehyde type of crosslinked resins also may be referred to as polyaromatic resins, and these polyelectrolyte core structures generally constitute part of the polymer backbone. Substituted variations are included in this disclosure, and use of the term porous crosslinked polyphenol or polyphenoxide resin includes, for example, those polyphenol or polyphenoxide resins that are substituted with electron-withdrawing groups or electron-donating groups or even combinations thereof.
Porous crosslinked polyphenoxide resins such as those used herein include associated cations, particularly associated metal cations, including Lewis acidic metal cations and cations with low Lewis acidity. According to an aspect, the associated metal cations can be an alkali metal, an alkaline earth metal, or any combination thereof. Typical associated metal cations can be, can comprise, or can be selected from lithium, sodium, potassium, magnesium, calcium, strontium, barium, aluminum, or zinc, and the like. Generally, sodium or potassium associated metal cations have been found to work well. Therefore, cations with a range of Lewis acidities in the particular solvent can be useful according to this disclosure.
The templating process that provides the high porosity and high density of associated metal (e.g. sodium) sites can use a basic particulate template, that has a solubility in water of less than about 0.25 g/L at 25° C. The basic particulate template also can have a solubility in water of less than about 0.10 g/L at 25° C. In an aspect, the basic particulate template, can have a solubility in water (all measured at 25° C.) of less than about 0.001 g/L, about 0.001 g/L, about 0.002 g/L, about 0.005 g/L, about 0.01 g/L, about 0.02 g/L, about 0.03 g/L, about 0.04 g/L, about 0.05 g/L, about 0.06 g/L, about 0.07 g/L, about 0.08 g/L, about 0.09 g/L, about 0.10 g/L, about 0.11 g/L, about 0.12 g/L, about 0.13 g/L, about 0.14 g/L, about 0.15 g/L, about 0.16 g/L, about 0.17 g/L, about 0.18 g/L, about 0.19 g/L, about 0.20 g/L, about 0.21 g/L, about 0.22 g/L, about 0.23 g/L, about 0.24 g/L, about 0.25 g/L, about 0.26 g/L, about 0.27 g/L, about 0.28 g/L, about 0.29 g/L, about 0.30 g/L, or greater than about 0.30 g/L (up to, for example, about 0.50 g/L), including any ranges or combination of ranges between any of these solubilities. For example, the basic particulate template also can have a solubility in water of from about 0.005 g/L to about 0.50 g/L, from about 0.5 g/L to about 0.50 g/L, from about 0.01 g/L to about 0.25 g/L, or about 0.05 g/L to about 0.20 g/L at 25° C.
The size of the basic particulate template also can vary, for example, the basic particulate template can have an average or median particle size from about 0.1 μm (micrometers) to about 50 μm, or can have an average or median particle size from about 10 μm (micrometers) to about 25 μm. In an aspect, the average or median particle size is measured by either dynamic light scattering tests or by a laser diffraction technique. In this aspect, the basic particulate template can have an average or median particle size of less than about 0.1 μm, about 0.2 μm, about 0.5 μm, about 1 μm, about 2 μm, about 3 μm, about 4 μm, about 5 μm, about 6 μm, about 7 μm, about 8 μm, about 9 μm, about 10 μm, about 11 μm, about 12 μm, about 15 μm, about 20 μm, about 25 μm, about 30 μm, about 35 μm, about 40 μm, about 45 μm, about 50 μm, about 55 μm, about 60 μm, about 65 μm, about 70 μm, about 75 μm, about 80 μm, about 85 μm, about 90 μm, about 95 μm, about 100 μm, about 125 μm, about 150 μm, about 175 μm, about 200 μm, about 250 μm, about 300 μm, about 350 μm, about 400 μm, about 450 μm, or about 500 μm, or greater than about 500 μm (up to, for example, about 750 μm), including any ranges or combination of ranges between any of these sizes. In a further aspect, nanometer-scale calcium carbonate can be prepared and used as a template to form a nanometer-scale porous crosslinked polyphenoxide resins. For example, nanometer-scale calcium carbonate can be prepared from calcium chloride and carbonic acid to control particulate size and morphology.
According to an aspect, the basic particulate template can comprise an alkaline earth metal carbonate, phosphate, monohydrogen phosphate, or dihydrogen phosphate, or combinations thereof. The basic particulate template generally has low solubility in water, and it can be reacted with aqueous acid to form soluble salts and other species, that allow for the formation of the porous structure of the crosslinked polyphenoxide resin. For example, the basic particulate template can comprise, consist essentially of, or consist of magnesium carbonate, calcium carbonate, strontium carbonate, tribasic calcium phosphate, calcium monohydrogen phosphate, or calcium dihydrogen phosphate, or combinations thereof. The basic particulate template comprises or can be selected from magnesium carbonate or calcium carbonate. Calcium carbonate is a useful basic templating material, and samples can have, for example, an average particle size from about 2 μm (micrometers) to about 200 μm, about 2 μm to about 100 μm, or about 2 μm to about 50 μm.
To form the templated polyphenol resin, at least one phenol compound, formaldehyde, and an aqueous base are contacted with the basic particulate template under polymerization conditions sufficient to form a templated crosslinked polyphenol resin, which comprises the crosslinked polyphenol resin in contact with the basic particulate template. The aqueous base can comprise or be selected from any suitable aqueous base or any aqueous base disclosed herein, for example, an alkaline metal hydroxide such as NaOH or KOH.
Once templated in this fashion, the templated crosslinked polyphenol resin is contacted with an aqueous acid under pore forming conditions sufficient to remove the basic particulate template and form a porous crosslinked polyphenol resin. The aqueous acid can comprise or can be selected from any suitable aqueous acid or any aqueous acid disclosed herein, for example, the aqueous acid can be a hydrohalic acid such as HCl(aq) or HBr(aq), but acids like aqueous nitric acid or sulfuric acid can be used. Strong organic acids can even be used in this fashion, for example, p-toluenesulfonic acid or methanesulfonic acid can be used for this process.
As noted, advantages of using treated phenol-formaldehyde resins include their insolubility, which allows the use of a range of solvents with these materials, and their relatively high phenol concentration that can be functionalized using a metal base such as an alkali metal hydroxide. An early version of the thermosetting phenol-formaldehyde resins formed from the condensation reaction of phenol with formaldehyde is Bakelite™, and various phenol-formaldehyde resins used herein may be referred to generically as “Bakelite” resins. In the context of this disclosure, the use of terms such as Bakelite or general terms such as phenol-formaldehyde resins contemplates that these materials will be treated with a metal-containing base or a metal cation source such as sodium hydroxide prior to their use in the processes disclosed.
In addition, other useful porous crosslinked polyphenol resins include substituted phenol-formaldehyde resins that are also generally crosslinked into insoluble resins. These resins can be formed from the condensation reaction of one or more of phenol, a polyhydroxyarene such as resorcinol (also, benzenediol or m-dihydroxybenzene), and/or their substituted analogs with formaldehyde. Therefore, these materials include resins made with more than one phenol as co-monomer. Treatment with bases such as NaOH or KOH also provides a ready method of functionalizing the polyaromatic polymers for the reactivity described herein.
In one example, a resin can be prepared using the monomer combination of resorcinol (m-dihydroxybenzene) and fluorophenol monomers with formaldehyde, and sodium-treated to generate the porous crosslinked polyphenol resin. While not intending to be theory bound, the meta-dihydroxybenzene is believed to add additional ion chelation functionality to the resin. Subsequent base (e.g. sodium hydroxide) treatment can be used to generate the porous crosslinked polyphenoxide that is a polyhydroxidearene resin. Such adjustments can provide flexibility for tailoring the reaction according to the specific olefin to be coupled with CO2, the reaction rate, the catalytic turnover, as well as additional reaction parameters and combinations of reaction parameters.
In other aspects and embodiments in which polymer support variations are used and/or in which the porous crosslinked polyphenoxide resin itself, after the templating synthesis, is used without a support, the porous crosslinked polyphenoxide resin embodiments can have any suitable surface area, pore volume, and particle size, as would be recognized as acceptable by those of skill in the art. For instance, the porous crosslinked polyphenoxide resin can have a pore volume in a range from 0.1 mL/g to 25 mL/g, from 0.5 mL/g to 10 mL/g, or alternatively, from 0.5 mL/g to 2.5 mL/g. In a further aspect, the porous crosslinked polyphenoxide can have a pore volume from 1 mL/g to 8 mL/g, or alternatively from 2 mL/g to 15 mL/g. Additionally, or alternatively, the porous crosslinked polyphenoxide resin can have a BET surface area in a range from 10 to 1,000 m2/g; alternatively, from 100 to 750 m2/g; or alternatively, from 100 to 500 m2/g or alternatively from 30 to 200 m2/g. In a further aspect, the porous crosslinked polyphenoxide resin can have a surface area of from 100 to 400 m2/g, from 200 to 450 m2/g, or from 150 to 350 m2/g. The average particle size of the porous crosslinked polyphenoxide resin can vary greatly depending upon the process specifics, however, average particle sizes in the range of from 2 to 500 μm, from 10 to 250 μm, or from 15 to 100 μm, are often employed. IN one aspect, the average or median particle size of the porous crosslinked polyphenoxide resin can mirror the average or median sizes recited for the basic particulate template.
The present disclosure also provides for various modifications of the polymeric anionic stationary phase (porous crosslinked polyphenoxide resins), for example, in a column or other suitable solid state configuration. Further various modifications of the polymeric anionic stationary phase (porous crosslinked polyphenoxide resins), for example, in a column or other suitable solid state configuration are useful in the processes disclosed herein. For example, acid-base reactions that generate the porous crosslinked polyphenoxide resin from the reacted polymer can be effected using a wide range of metal bases, including alkali and alkaline hydroxides, alkoxides, aryloxides, amides, alkyl or aryl amides, and the like, such that an assortment of electrophiles can be used in nickelalactone destabilization.
According to an aspect, disclosed herein is a porous crosslinked polyphenol resin, the resin comprising a phenol-formaldehyde resin, a polyhydroxyarene-formaldehyde resin, a polyhydroxyarene- and fluorophenol-formaldehyde resin, or any combination thereof, and having an average particle size from about 2 μm (micrometers) to about 50 μm and an average pore diameter from about 2 nm (nanometers) to about 250 nm. In a further aspect, there is provided a porous crosslinked polyphenoxide resin, the resin comprising a phenoxide-formaldehyde resin, a polyhydroxidearene-formaldehyde resin, a polyhydroxidearene- and fluorophenoxide-formaldehyde resin, or any combination thereof; and associated metal cations comprising lithium, sodium, potassium, magnesium, calcium, strontium, barium, aluminum, or zinc; wherein the porous crosslinked polyphenoxide resin has an average particle size from about 2 μm (micrometers) to about 50 μm and an average pore diameter from about 2 nm (nanometers) to about 250 nm.
Referring again to Scheme 1, the disclosed processes can further include the step of reacting the byproduct reacted polymer, such as a crosslinked polyphenol resin, with a base. For example a base, which are also termed a regenerative base, can be used to regenerate the crosslinked polyphenol resin byproduct to the porous crosslinked polyphenoxide resin reactant. The regenerative base can comprise a metal ion or a metal ion source, for example a metal-stabilized base such as metal hydroxide or metal alkoxide can be used. Thus, in the example of Scheme 1, the porous crosslinked polyphenoxide resin can be a metallated crosslinked polyphenoxide resin, which is formed upon the reaction of the reacted polymer, for example crosslinked polyphenol resin, with a base such as a metal-containing base. For example, the metal in a metal-containing base can be, but is not limited to, a metal of Groups 1, 2, 12 or 13, such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, zinc, aluminum or gallium.
The step of regenerating the porous crosslinked polyphenoxide resin can be effected by contacting the porous crosslinked polyphenol resin with a regenerative base comprising a metal cation following the formation of the α,β-unsaturated carboxylic acid or a salt thereof. A wide range of bases can be used for this regeneration step. For example, the regenerative base can be or can comprise metal-containing bases which can include any reactive inorganic basic metal compound or mixture of compounds that contain metal cations or cation sources, for example, alkali and alkaline earth metal compounds such as oxides, hydroxides, alkoxides, aryloxides, amides, alkyl amides, arylamides, and carbonates. Suitable bases include or comprise, for example, carbonates (e.g., Na2CO3, Cs2CO3, MgCO3), hydroxides (e.g., Mg(OH)2, Ca(OH)2, NaOH, KOH), alkoxides (e.g., Al(OiPr)3, Na(OtBu), Mg(OEt)2), aryloxides (e.g. Na(OC6H5), sodium phenoxide) and the like. In an aspect, certain porous crosslinked polyphenol resins with particularly acidic phenolic groups can be regenerated to the porous crosslinked polyphenoxide resin reactant upon its reaction with only a metal-containing salt such as sodium chloride. Such resins can have electron-withdrawing substituents situated ortho or para to the phenol hydroxyl group, such that the anionic form can readily form and only a metal-containing salt (or “metal salt”) such as sodium chloride is required to regenerate polyphenoxide resin. Typically, this regeneration step further comprising or is followed by the step of washing the porous crosslinked polyphenoxide resin with a solvent or the diluent.
According to an aspect, the regenerative base can be or can comprise a nucleophilic base, for example a metal hydroxide or metal alkoxide. While the regenerative base can comprise a non-nucleophilic base, the processes disclosed herein works well in the absence of non-nucleophilic bases, for example, in the absence of an alkali metal hydride or an alkaline earth metal hydride, an alkali metal or alkaline earth metal dialkylamides and diarylamides, an alkali metal or alkaline earth metal hexalkyldisilazane, and an alkali metal or alkaline earth metal dialkylphosphides and diarylphosphides. Therefore, in a particular aspect, the regenerating process can be carried out in the absence of a non-nucleophilic base, such as in the absence of a metal hydride.
Typically, the inorganic bases such as alkali metal hydroxides or alkali metal alkoxides have been found to work the best. However, in one aspect, the reaction of Scheme 1 can be conducted using some bases but in the absence of certain other organic bases such as an alkoxide, aryloxide, amide, alkyl amide, arylamide, or the like. In another aspect, the porous crosslinked polyphenoxide resin (and associated cations) can be used and regenerated in the absence of an alkoxide or aryloxide. Further, the reactions and processes disclosed herein can be conducted in the absence of an alkoxide, an aryloxide, an alkylamide, an arylamide, an amine, a hydride, a phosphazene, and/or substituted analogs thereof. For example, the processes disclosed herein can be conducted in the absence of sodium hydride, an aryloxide salt (such as a sodium aryloxide), an alkoxide salt (such as a sodium tert-butoxide), and/or a phosphazene.
The processes disclosed herein typically are conducted in the presence of a diluent. Mixtures and combinations of diluents can be utilized in these processes. The diluent can comprise, consist essentially of, or consist of, any suitable solvent or any solvent disclosed herein, unless otherwise specified. For example, the diluent can comprise, consist essentially of, or consist of a non-protic solvent, a protic solvent, a non-coordinating solvent, or a coordinating solvent. For instance, in accordance with one aspect of this disclosure, the diluent can comprise a non-protic solvent. Representative and non-limiting examples of non-protic solvents can include tetrahydrofuran (THF), 2,5-Me2THF, acetone, toluene, chlorobenzene, pyridine, acetonitrile, carbon dioxide, olefin, and the like, as well as combinations thereof. In accordance with another aspect, the diluent can comprise a weakly coordinating or non-coordinating solvent. Representative and non-limiting examples of weakly coordinating or non-coordinating solvents can include toluene, chlorobenzene, paraffins, halogenated paraffins, and the like, as well as combinations thereof.
In accordance with yet another aspect, the diluent can comprise a carbonyl-containing solvent, for instance, ketones, esters, amides, and the like, as well as combinations thereof. Representative and non-limiting examples of carbonyl-containing solvents can include acetone, ethyl methyl ketone, ethyl acetate, propyl acetate, butyl acetate, isobutyl isobutyrate, methyl lactate, ethyl lactate, N,N-dimethylformamide, and the like, as well as combinations thereof. In still another aspect, the diluent can comprise THF, 2,5-Me2THF, methanol, acetone, toluene, chlorobenzene, pyridine, acetonitrile, anisole, or a combination thereof; alternatively, THF; alternatively, 2,5-Me2THF; alternatively, methanol; alternatively, acetone; alternatively, toluene; alternatively, chlorobenzene; or alternatively, pyridine.
In an aspect, the diluent can comprise (or consist essentially of, or consist of) an aromatic hydrocarbon solvent. Non-limiting examples of suitable aromatic hydrocarbon solvents that can be utilized singly or in any combination include benzene, toluene, xylene (inclusive of ortho-xylene, meta-xylene, para-xylene, or mixtures thereof), and ethylbenzene, or combinations thereof; alternatively, benzene; alternatively, toluene; alternatively, xylene; or alternatively, ethylbenzene.
In an aspect, the diluent can comprise (or consist essentially of, or consist of) a halogenated aromatic hydrocarbon solvent. Non-limiting examples of suitable halogenated aromatic hydrocarbon solvents that can be utilized singly or in any combination include chlorobenzene, dichlorobenzene, and combinations thereof; alternatively, chlorobenzene; or alternatively, dichlorobenzene.
In an aspect, the diluent can comprise (or consist essentially of, or consist of) an ether solvent. Non-limiting examples of suitable ether solvents that can be utilized singly or in any combination include dimethyl ether, diethyl ether, diisopropyl ether, di-n-propyl ether, di-n-butyl ether, diphenyl ether, methyl ethyl ether, methyl t-butyl ether, dihydrofuran, tetrahydrofuran (THF), 2,5-Me2THF, 1,2-dimethoxyethane, 1,4-dioxane, anisole, and combinations thereof; alternatively, diethyl ether, dibutyl ether, THF, 2,5-Me2THF, 1,2-dimethoxyethane, 1,4-dioxane, and combinations thereof; alternatively, THF; or alternatively, diethyl ether.
In a further aspect, any of these aforementioned diluents can be excluded from the diluent or diluent mixture. For example, the diluent can be absent a phenol or a substituted phenol, an alcohol or a substituted alcohol, an amine or a substituted amine, water, an ether, an aliphatic hydrocarbon solvent, an aromatic hydrocarbon solvent, an aldehyde or ketone, an ester or amide, and/or absent a halogenated aromatic hydrocarbon, or any substituted analogs of these diluents halogenated analogs, including any of the aforementioned diluents. Therefore, Applicant reserves the right to exclude any of the diluents provided herein.
In all aspects and embodiments disclosed herein, the diluent can include or comprise carbon dioxide, olefin, or combinations thereof. At least a portion of the diluent can comprise the α,β-unsaturated carboxylic acid or the salt thereof, formed in the process.
In this disclosure, the term transition metal precursor, transition metal compound, transition metal catalyst, transition metal precursor compound, carboxylation catalyst, transition metal precursor complex, transition metal-ligand complex, and similar terms refer to a chemical compound that serves as the precursor to the metalalactone, prior to the coupling of the olefin and carbon dioxide at the metal center of the transition metal precursor compound. Therefore, the metal of the transition metal precursor compound and the metal of the metalalactone are the same. In some aspects, some of the ligands of the transition metal precursor compound carry over and are retained by the metalalactone following the coupling reaction. In other aspects, the transition metal precursor compound loses its existing ligands, referred to herein as first ligands, in presence of additional ligands such as chelating ligands, referred to herein as second ligands, as the metalalactone is formed. Therefore, the metalalactone generally incorporates the second (added) ligand(s), though in some aspects, the metalalactone can comprise the first ligand(s) that were bound in the transition metal precursor compound.
According to an aspect, the transition metal catalyst or compound used in the processes can be used without being immobilized on a solid support. That is the transition metal catalyst can be used is its usual form which is soluble in most useful solvents, without being bonded to or supported on any insoluble support, such as an inorganic oxide or mixed oxide material.
A prototypical example of a transition metal precursor compound that loses its initial ligands in the coupling reaction in the presence of a second (added) ligand, wherein the metalalactone incorporates the second (added) ligand(s), is contacting Ni(COD)2 (COD is 1,5-cyclooctadiene) with a diphosphine ligand such as 1,2-bis(dicyclohexylphosphino)ethane in a diluent in the presence of ethylene and CO2 to form a nickelalactone with a coordinated 1,2-bis(dicyclohexylphosphino)ethane bidentate ligand.
According to an aspect, any of the metalalactone ligand (that is, any ligand of the metalalactone compound other than the metalalactone moiety), the first ligand, or the second ligand can be any suitable neutral electron donor group and/or Lewis base, or any neutral electron donor group and/or Lewis base disclosed herein. For example, any of the metalalactone ligand, the first ligand, or the second ligand can be a bidentate ligand. Any of the metalalactone ligand, the first ligand, or the second ligand can comprise at least one of a nitrogen, phosphorus, sulfur, or oxygen heteroatom. For example, any of the metalalactone ligand, the first ligand, or the second ligand comprises or is selected from a diphosphine ligand, a diamine ligand, a diene ligand, a diether ligand, or dithioether ligand.
Accordingly, in an aspect, the process for forming an α,β-unsaturated carboxylic acid or a salt thereof, can comprise:
Generally, the processes disclosed herein employ a metalalactone or a transition metal precursor compound or complex. The transition metal of the metalalactone, or of the transition metal precursor compound, can be a Group 3 to Group 8 transition metal or, alternatively, a Group 8 to Group 11 transition metal. In one aspect, for instance, the transition metal can be Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Pt, or Au, while in another aspect, the transition metal can be Fe, Ni, or Rh. Alternatively, the transition metal can be Fe; alternatively, the transition metal can be Co; alternatively, the transition metal can be Ni; alternatively, the transition metal can be Cu; alternatively, the transition metal can be Ru; alternatively, the transition metal can be Rh; alternatively, the transition metal can be Pd; alternatively, the transition metal can be Ag; alternatively, the transition metal can be Ir; alternatively, the transition metal can be Pt; or alternatively, the transition metal can Au.
In particular aspects contemplated herein, the transition metal can be Ni. Hence, the metalalactone can be a nickelalactone and the transition metal precursor compound can be a Ni-ligand complex in these aspects.
The ligand of the metalalactone and/or of the transition metal precursor compound, can be any suitable neutral electron donor group and/or Lewis base. For instance, the suitable neutral ligands can include sigma-donor solvents that contain a coordinating atom (or atoms) that can coordinate to the transition metal of the metalalactone (or of the transition metal precursor compound). Examples of suitable coordinating atoms in the ligands can include, but are not limited to, O, N, S, and P, or combinations of these atoms. In some aspects consistent with this disclosure, the ligand can be a bidentate ligand.
In an aspect, the ligand used to form the metalalactone and/or the transition metal precursor compound can be an ether, an organic carbonyl, a thioether, an amine, a nitrile, or a phosphine. In another aspect, the ligand used to form the metalalactone or the transition metal precursor compound can be an acyclic ether, a cyclic ether, an acyclic organic carbonyl, a cyclic organic carbonyl, an acyclic thioether, a cyclic thioether, a nitrile, an acyclic amine, a cyclic amine, an acyclic phosphine, or a cyclic phosphine.
Suitable ethers can include, but are not limited to, dimethyl ether, diethyl ether, dipropyl ether, dibutyl ether, methyl ethyl ether, methyl propyl ether, methyl butyl ether, diphenyl ether, ditolyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, 2,3-dihydrofuran, 2,5-dihydrofuran, furan, benzofuran, isobenzofuran, dibenzofuran, tetrahydropyran, 3,4-dihydro-2H-pyran, 3,6-dihydro-2H-pyran, 2H-pyran, 4H-pyran, 1,3-dioxane, 1,4-dioxane, morpholine, and the like, including substituted derivatives thereof.
Suitable organic carbonyls can include ketones, aldehydes, esters, and amides, either alone or in combination, and illustrative examples can include, but are not limited to, acetone, acetophenone, benzophenone, N,N-dimethylformamide, N,N-dimethylacetamide, methyl acetate, ethyl acetate, and the like, including substituted derivatives thereof.
Suitable thioethers can include, but are not limited to, dimethyl thioether, diethyl thioether, dipropyl thioether, dibutyl thioether, methyl ethyl thioether, methyl propyl thioether, methyl butyl thioether, diphenyl thioether, ditolyl thioether, thiophene, benzothiophene, tetrahydrothiophene, thiane, and the like, including substituted derivatives thereof.
Suitable nitriles can include, but are not limited to, acetonitrile, propionitrile, butyronitrile, benzonitrile, 4-methylbenzonitrile, and the like, including substituted derivatives thereof.
Suitable amines can include, but are not limited to, methyl amine, ethyl amine, propyl amine, butyl amine, dimethyl amine, diethyl amine, dipropyl amine, dibutyl amine, trimethyl amine, triethyl amine, tripropyl amine, tributyl amine, aniline, diphenylamine, triphenylamine, tolylamine, xylylamine, ditolylamine, pyridine, quinoline, pyrrole, indole, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2,5-dimethylpyrrole, 2,5-diethylpyrrole, 2,5-dipropylpyrrole, 2,5-dibutylpyrrole, 2,4-dimethylpyrrole, 2,4-diethylpyrrole, 2,4-dipropylpyrrole, 2,4-dibutylpyrrole, 3,4-dimethylpyrrole, 3,4-diethylpyrrole, 3,4-dipropylpyrrole, 3,4-dibutylpyrrole, 2-methylpyrrole, 2-ethylpyrrole, 2-propylpyrrole, 2-butylpyrrole, 3-methylpyrrole, 3-ethylpyrrole, 3-propylpyrrole, 3-butylpyrrole, 3-ethyl-2,4-dimethylpyrrole, 2,3,4,5-tetramethylpyrrole, 2,3,4,5-tetraethylpyrrole, 2,2′-bipyridine, 1,8-Diazabicyclo[5.4.0]undec-7-ene, di(2-pyridyl)dimethylsilane, N,N,N′,N′-tetramethylethylenediamine, 1,10-phenanthroline, 2,9-dimethyl-1,10-phenanthroline, glyoxal-bis(mesityl)-1,2-diimine and the like, including substituted derivatives thereof. Suitable amines can be primary amines, secondary amines, or tertiary amines.
Suitable phosphines and other phosphorus compounds can include, but are not limited to, trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, phenylphosphine, tolylphosphine, diphenylphosphine, ditolylphosphine, triphenylphosphine, tritolylphosphine, methyldiphenylphosphine, dimethylphenylphosphine, ethyldiphenylphosphine, diethylphenylphosphine, tricyclohexylphosphine, trimethyl phosphite, triethyl phosphite, tripropyl phosphite, triisopropyl phosphite, tributyl phosphite and tricyclohexyl phosphite, 2-(di-t-butylphosphino)biphenyl, 2-di-t-butylphosphino-1,1′-binaphthyl, 2-(di-t-butylphosphino)-3,6-dimethoxy-2′,4′,6′-tri-i-propyl-1,1′-biphenyl, 2-di-t-butylphosphino-2′-methylbiphenyl, 2-(di-t-butylphosphinomethyl)pyridine, 2-di-t-butylphosphino-2′,4′,6′-tri-i-propyl-1,1′-biphenyl, 2-(dicyclohexylphosphino)biphenyl, (S)-(+)-(3,5-dioxa-4-phospha-cyclohepta[2,1-a;3,4-a′]dinaphthalen-4-yl)dimethylamine, 2-(diphenylphosphino)-2′-methoxy-1,1′-binaphthyl, 1,2,3,4,5-pentaphenyl-1′-(di-t-butylphosphino)ferrocene, 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP), 1,2-bis(dimethylphosphino)ethane, 1,2-bis(diethylphosphino)ethane, 1,2-bis(dipropylphosphino)-ethane, 1,2-bis(diisopropylphosphino)ethane, 1,2-bis(dibutyl-phosphino)ethane, 1,2-bis(di-t-butyl-phosphino)ethane, 1,2-bis(dicyclohexylphosphino)ethane, 1,3-bis(dicyclohexylphosphino)propane, 1,3-bis(diisopropylphosphino)propane, 1,3-bis(diphenylphosphino)propane, 1,3-bis(di-t-butylphosphino)propane, 1,4-bis(diisopropylphosphino)butane, 1,4-bis(diphenylphosphino)butane, 2,2′-bis[bis(3,5-dimethylphenyl)phosphino]-4,4′,6,6′-tetramethoxybiphenyl, 2,6-bis(di-t-butylphosphinomethyl)pyridine, 2,2′-bis(dicyclohexylphosphino)-1,1′-biphenyl, bis(2-dicyclohexylphosphinophenyl)ether, 5,5′-bis(diphenylphosphino)-4,4′-bi-1,3-benzodioxole, 2-t-butylphosphinomethylpyridine, bis(diphenylphosphino)ferrocene, bis(diphenylphosphino)methane, bis(dicyclohexylphosphino)methane, bis(di-t-butylphosphino)methane, and the like, including substituted derivatives thereof.
In other aspects, the ligand used to form the metalalactone or the transition metal precursor compound can be a carbene, for example, a N-heterocyclic carbene (NHC) compound. Representative and non-limiting examples of suitable N-heterocyclic carbene (NHC) materials include the following:
Illustrative and non-limiting examples of metalalactone complexes (representative nickelalactones) suitable for use as described herein include the following compounds (Cy=cyclohexyl, tBu=tert-butyl):
The transition metal precursor compounds corresponding to these illustrative metalalactones are shown below:
Metalalactones can be synthesized according to the following general reaction scheme (illustrated with nickel as the transition metal; Ni(COD)2 is bis(1,5-cyclooctadiene)nickel(0)), and according to suitable procedures well known to those of skill in the art.
Suitable ligands, transition metal precursor compounds, and metalalactones are not limited solely to those ligands, transition metal precursor compounds, and metalalactones disclosed herein. Other suitable ligands, transition metal precursor compounds, and metalalactones are described, for example, in U.S. Pat. Nos. 7,250,510, 8,642,803, and 8,697,909; Journal of Organometallic Chemistry, 1983, 251, C51-053; Z. Anorg. Allg. Chem., 1989, 577, 111-114; Journal of Organometallic Chemistry, 2004, 689, 2952-2962; Organometallics, 2004, Vol. 23, 5252-5259; Chem. Commun., 2006, 2510-2512; Organometallics, 2010, Vol. 29, 2199-2202; Chem. Eur. J., 2012, 18, 14017-14025; Organometallics, 2013, 32 (7), 2152-2159; and Chem. Eur. J., 2014, Vol. 20, 11, 3205-3211; the disclosures of which are incorporated herein by reference in their entireties.
The following references provide information related to the structure and/or activity relationships in the olefin and CO2 coupling process, as observed by changes in phenoxide structure, the phosphine ligand structure, and other ligand structures: Manzini, S.; Huguet, N.; Trapp, O.; Schaub, T. Eur. J. Org. Chem. 2015, 7122; and Al-Ghamdi, M.; Vummaleti, S. V. C.; Falivene, L.; Pasha, F. A.; Beetstra, D. J.; Cavallo, L. Organometallics 2017, 36, 1107-1112. These references are incorporated herein by reference in their entireties.
By adjusting the basic particulate template size, molar ratio of formaldehyde to phenol monomer, polymerization conditions, and the like, the properties of the porous crosslinked polyphenoxide resin co-catalyst can be adjusted which can, in turn, provide higher turnover numbers. For example, the sodium site density and/or polymer surface area can be increased or maximized to provide higher turnovers. The pore size and/or pore density can be increased or adjusted to accommodate larger metalalactone intermediates that provide specific acrylates including various substituted acrylates.
Generally, the features of the processes disclosed herein (e.g., the metalalactone, the diluent, the porous crosslinked polyphenol and polyphenoxide resin, the α,β-unsaturated carboxylic acid or salt thereof, the transition metal precursor compound, the olefin, and the reaction conditions under which the α,β-unsaturated carboxylic acid, or a salt thereof, is formed, among others) are independently described, and these features can be combined in any combination to further describe the disclosed processes.
In accordance with an aspect of the present disclosure, a process for performing a metalalactone elimination reaction is disclosed, in which the process forms an α,β-unsaturated carboxylic acid or salt thereof. This process can comprise (or consist essentially of, or consist of):
Suitable metalalactones, diluents, and porous crosslinked polyphenol resins are disclosed hereinabove. In this process for performing a metalalactone elimination reaction, for instance, at least a portion of the diluent can comprise the α,β-unsaturated carboxylic acid, or the salt thereof, that is formed in step (2) of this process.
In accordance with another aspect of the present disclosure, a process for producing an α,β-unsaturated carboxylic acid, or a salt thereof, is disclosed. This process can comprise (or consist essentially of, or consist of):
As discussed further in this disclosure, the above processes can further comprise a step of contacting a transition metal precursor compound comprising at least one first ligand, an olefin, and carbon dioxide (CO2) to form the metalalactone compound. That is, at least one ligand of the transition metal precursor compound can be carried over to the metalalactone compound. In further aspects, the above processes can further comprise a step of contacting a transition metal precursor compound comprising at least one first ligand with at least one second ligand, an olefin, and carbon dioxide (CO2) to form the metalalactone compound. In this aspect, the ligand set of the metalalactone typically comprises the at least one ligand in addition to the metalalactone moiety. That is, the metalalactone compound can comprise the at least one first ligand, the at least one second ligand, or a combination thereof.
In some aspects, the contacting step—step (1)—of the above processes can include contacting, in any order, the metalalactone, the diluent, and the porous crosslinked polyphenoxide resin, and additional unrecited materials. In other aspects, the contacting step can consist essentially of, or consist of, the metalalactone, the diluent, and the porous crosslinked polyphenoxide resin components. Likewise, additional materials or features can be employed in the applying reaction conditions step—step (2)—that forms or produces the α,β-unsaturated carboxylic acid, or the salt thereof. Further, it is contemplated that these processes for producing an α,β-unsaturated carboxylic acid or a salt thereof by a metalalactone elimination reaction can employ more than one metalalactone and/or more than one porous crosslinked polyphenoxide resin. Additionally, a mixture or combination of two or more diluents can be employed.
Any suitable reactor, vessel, or container can be used to contact the metalalactone, diluent, and porous crosslinked polyphenoxide resin, non-limiting examples of which can include a flow reactor, a continuous reactor, a fixed bed reactor, a moving reactor bed, and a stirred tank reactor, including more than one reactor in series or in parallel, and including any combination of reactor types and arrangements. In particular aspects consistent with this disclosure, the metalalactone and the diluent can contact a fixed bed of the porous crosslinked polyphenoxide resin, for instance, in a suitable vessel, such as in a continuous fixed bed reactor. In further aspects, combinations of more than one porous crosslinked polyphenoxide resin can be used, such as a mixed bed of a first porous crosslinked polyphenoxide resin and a second porous crosslinked polyphenoxide resin, or sequential beds of a first porous crosslinked polyphenoxide resin and a second porous crosslinked polyphenoxide resin. In these and other aspects, the feed stream can flow upward or downward through the fixed bed. For instance, the metalalactone and the diluent can contact the first porous crosslinked polyphenoxide resin and then the second porous crosslinked polyphenoxide resin in a downward flow orientation, and the reverse in an upward flow orientation. In a different aspect, the metalalactone and the porous crosslinked polyphenoxide resin can be contacted by mixing or stirring in the diluent, for instance, in a suitable vessel, such as a stirred tank reactor.
Step (1) of the process for producing an α,β-unsaturated carboxylic acid or a salt thereof also recites forming an adduct of the metalalactone and the porous crosslinked polyphenoxide resin and its associated metal cations. Without intending to be bound by theory, there is some interaction between the metalalactone and the porous crosslinked polyphenoxide resin and its associated metal cations that are believed to destabilize the metalalactone for its elimination of the metal acrylate. This interaction can be referred to generally as an adduct of the metalalactone and the porous crosslinked polyphenoxide resin or an adduct of the α,β-unsaturated carboxylic acid with the porous crosslinked polyphenoxide resin. This adduct can contain all or a portion of the α,β-unsaturated carboxylic acid and can be inclusive of salts of the α,β-unsaturated carboxylic acid.
Accordingly, applying reaction conditions or process conditions to the reaction mixture suitable to form an α,β-unsaturated carboxylic acid or a salt thereof is intended to reflect any concomitant or subsequent reaction conditions to step (1) of the above processes that release the α,β-unsaturated carboxylic acid or a salt thereof from the adduct, regardless of the specific nature of the adduct.
For example, in step (2) of the process of applying reaction conditions or process conditions to the reaction mixture suitable to form an α,β-unsaturated carboxylic acid or a salt thereof, the adduct of the metalalactone and the porous crosslinked polyphenoxide resin and its associated metal cations as defined herein are subjected to some chemical or other reaction conditions or treatment to produce the α,β-unsaturated carboxylic acid or its salt. Various methods can be used to liberate the α,β-unsaturated carboxylic acid or its salt, from the porous crosslinked polyphenoxide resin. In one aspect, for instance, the treating step can comprise contacting the adduct of the metalalactone and the porous crosslinked polyphenoxide resin and its associated metal cations with an acid. Representative and non-limiting examples of suitable acids can include HCl, acetic acid, and the like, as well as combinations thereof. In another aspect, the treating step can comprise contacting the adduct of the metalalactone and the porous crosslinked polyphenoxide resin and its associated metal cations with a base. Representative and non-limiting examples of suitable bases can include carbonates (e.g., Na2CO3, Cs2CO3, MgCO3), hydroxides (e.g., Mg(OH)2, Na(OH), alkoxides (e.g., Al(OiPr)3, Na(OtBu), Mg(OEt)2), and the like, as well as combinations thereof (iPr=isopropyl, tBu=tert-butyl, Et=ethyl). In yet another aspect, the treating step can comprise contacting the adduct of the metalalactone and the porous crosslinked polyphenoxide resin and its associated metal cations with a suitable solvent. Representative and non-limiting examples of suitable solvents can include carbonyl-containing solvents such as ketones, esters, amides, etc. (e.g., acetone, ethyl acetate, N,N-dimethylformamide, etc., as described herein above), alcohol solvents, water, and the like, as well as combinations thereof.
In still another aspect, the treating step can comprise heating the adduct of the metalalactone and the porous crosslinked polyphenoxide resin and its associated metal cations to any suitable temperature. This temperature can be in a range, for example, from 50 to 1000° C., from 100 to 800° C., from 150 to 600° C., from 250 to 1000° C., from 250° C. to 550° C., or from 150° C. to 500° C. The duration of this heating step is not limited to any particular period of time, as long of the period of time is sufficient to liberate the α,β-unsaturated carboxylic acid from the porous crosslinked polyphenoxide resin. As those of skill in the art recognize, the appropriate treating step depends upon several factors, such as the particular diluent used in the process, and the particular porous crosslinked polyphenoxide resin used in the process, amongst other considerations. One further treatment step can comprise, for example, a workup step with additional olefin to displace an alkene-nickel bound acrylate.
In these processes for performing a metalalactone elimination reaction and for producing an α,β-unsaturated carboxylic acid (or a salt thereof), additional process steps can be conducted before, during, and/or after any of the steps described herein. As an example, these processes can further comprise a step (e.g., prior to step (1)) of contacting a transition metal precursor compound with an olefin and carbon dioxide to form the metalalactone. Transition metal precursor compound are described hereinabove. Illustrative and non-limiting examples of suitable olefins can include ethylene, propylene, butene (e.g., 1-butene), pentene, hexene (e.g., 1-hexene), heptane, octene (e.g., 1-octene), and styrene and the like, as well as combinations thereof.
Yet, in accordance with another aspect of the present disclosure, a process for producing an α,β-unsaturated carboxylic acid, or a salt thereof, is disclosed. This process can comprise (or consist essentially of, or consist of):
In aspects of this process that utilizes a transition metal precursor compound comprising at least one first ligand, the olefin can be ethylene, and the step of contacting a transition metal precursor compound with an olefin and carbon dioxide (CO2) can be conducted using any suitable pressure of ethylene, or any pressure of ethylene disclosed herein, e.g., from 10 psig (70 KPa) to 1,000 psig (6,895 KPa), from 25 psig (172 KPa) to 500 psig (3,447 KPa), or from 50 psig (345 KPa) to 300 psig (2,068 KPa), and the like. Further, the olefin can be ethylene, and the step of contacting a transition metal precursor compound with an olefin and carbon dioxide (CO2) can be conducted using a constant addition of the olefin, a constant addition of carbon dioxide, or a constant addition of both the olefin and carbon dioxide, to provide the reaction mixture. By way of example, in a process wherein the ethylene and carbon dioxide (CO2) are constantly added, the process can utilize an ethylene:CO2 molar ratio of from 5:1 to 1:5, from 3:1 to 1:3, from 2:1 to 1:2, or about 1:1, to provide the reaction mixture.
According to a further aspect of the above process that utilizes a transition metal precursor compound, the process can include the step of contacting a transition metal precursor compound with an olefin and carbon dioxide (CO2) conducted using any suitable pressure of CO2, or any pressure of CO2 disclosed herein, e.g., from 20 psig (138 KPa) to 2,000 psig (13,790 KPa), from 50 psig (345 KPa) to 750 psig (5,171 KPa), or from 100 psig (689 KPa) to 300 psig (2,068 KPa), and the like. In any of the processes disclosed herein, the processes can further comprise a step of monitoring the concentration of at least one reaction mixture component, at least one elimination reaction product, or a combination thereof, for any reason, such as to adjust process parameters in real time, to determine extent or reaction, or to stop the reaction at the desired point.
As illustrated, this process that utilizes a transition metal precursor compound comprising at least one first ligand includes one aspect in which no second ligand is employed in the contacting step, and another aspect in which a second ligand is used in the contacting step. That is, one aspect involves the contacting step of the process comprising contacting the transition metal precursor compound comprising at least one first ligand with the at least one second ligand. The order of contacting can be varied. For example, the contacting step of the process disclosed above can comprise contacting (a) the transition metal precursor compound comprising at least one first ligand with (b) the at least one second ligand to form a pre-contacted mixture, followed by contacting the pre-contacted mixture with the remaining components (c)-(f) in any order to provide the reaction mixture.
Further aspects or embodiments related to the order of contacting, for example, the contacting step can include or comprise contacting the metalalactone, the diluent, and the porous crosslinked polyphenoxide resin in any order. The contacting step can also comprise contacting the metalalactone and the diluent to form a first mixture, followed by contacting the first mixture with the porous crosslinked polyphenoxide resin to form the reaction mixture. In a further aspect, the contacting step can comprise contacting the diluent and the porous crosslinked polyphenoxide resin to form a first mixture, followed by contacting the first mixture with the metalalactone to form the reaction mixture. In yet a further aspect, the contacting step of the process can further comprise contacting any number of additives, for example, additives that can be selected from an acid, a base, or a reductant.
Suitable transition metal-ligand complexes, olefins, diluents, porous crosslinked polyphenoxide resins comprising associated metal cations are disclosed hereinabove. In some aspects, the contacting step—step (1)—of this process can include contacting, in any order, the transition metal-ligand complexes, the olefin, the diluent, the porous crosslinked polyphenoxide resin and carbon dioxide, and additional unrecited materials. In other aspects, the contacting step can consist essentially of, or consist of, contacting, in any order, the transition metal-ligand complex, the olefin, the diluent, the porous crosslinked polyphenoxide resin, and carbon dioxide. Likewise, additional materials or features can be employed in the forming step of step (2) of this process. Further, it is contemplated that this processes for producing an α,β-unsaturated carboxylic acid, or a salt thereof, can employ more than one transition metal-ligand complex and/or more than one porous crosslinked polyphenoxide resin if desired and/or more than one olefin. Additionally, a mixture or combination of two or more diluents can be employed.
As above, any suitable reactor, vessel, or container can be used to contact the transition metal-ligand complex, olefin, diluent, porous crosslinked polyphenoxide resin, and carbon dioxide, whether using a fixed bed of the porous crosslinked polyphenoxide resin, a stirred tank for contacting (or mixing), or some other reactor configuration and process. While not wishing to be bound by the following theory, a proposed and illustrative reaction scheme for this process is provided below.
Independently, the contacting and forming steps of any of the processes disclosed herein (i.e., for performing a metalalactone elimination reaction, for producing an α,β-unsaturated carboxylic acid, or a salt thereof), can be conducted at a variety of temperatures, pressures, and time periods. For instance, the temperature at which the components in step (1) are initially contacted can be the same as, or different from, the temperature at which the forming step (2) is performed. As an illustrative example, in the contacting step, the components can be contacted initially at temperature T1 and, after this initial combining, the temperature can be increased to a temperature T2 for the forming step (e.g., to form the α,β-unsaturated carboxylic acid, or the salt thereof). Likewise, the pressure can be different in the contacting step and the forming step. Often, the time period in the contacting step can be referred to as the contact time, while the time period in forming step can be referred to as the reaction time. The contact time and the reaction time can be, and often are, different.
In an aspect, the contacting step and/or the forming step of the processes disclosed herein can be conducted at a temperature in a range from 0° C. to 250° C.; alternatively, from 20° C. to 200° C.; alternatively, from 0° C. to 95° C.; alternatively, from 10° C. to 75° C.; alternatively, from 10° C. to 50° C.; or alternatively, from 15° C. to 70° C. In these and other aspects, after the initial contacting, the temperature can be changed, if desired, to another temperature for the forming step. These temperature ranges also are meant to encompass circumstances where the contacting step and/or the forming step can be conducted at a series of different temperatures, instead of at a single fixed temperature, falling within the respective ranges.
In an aspect, the contacting step and/or the forming step of the processes disclosed herein can be conducted at a pressure in a range from 5 (34 KPa) to 10,000 psig (68,948 KPa), such as, for example, from 5 psig (34 KPa) to 2500 psig (17,237 KPa). In some aspects, the pressure can be in a range from 5 psig (34 KPa) to 500 psig (3,447 KPa); alternatively, from 25 psig (172 KPa) to 3000 psig (20,684 KPa); alternatively, from 45 psig (310 KPa) to 1000 psig (6,895 KPa); or alternatively, from 50 psig (345 KPa) to 250 psig (1,724 KPa).
The contacting step of the processes is not limited to any particular duration of time. That is, the respective components can be initially contacted rapidly, or over a longer period of time, before commencing the forming step. Hence, the contacting step can be conducted, for example, in a time period ranging from as little as 1-30 seconds to as long as 1-12 hours, or more. In non-continuous or batch operations, the appropriate reaction time for the forming step can depend upon, for example, the reaction temperature, the reaction pressure, and the ratios of the respective components in the contacting step, among other variables. Generally, however, the forming step can occur over a time period that can be in a range from 1 minute to 96 hours, such as, for example, from 2 minutes to 96 hours, from 5 minutes to 72 hours, from 10 minutes to 72 hours, or from 15 minutes to 48 hours.
If the process employed is a continuous process, then the metalalactone/anionic electrolyte catalyst contact/reaction time (or the transition metal-ligand complex/anionic electrolyte catalyst contact/reaction time) can be expressed in terms of weight hourly space velocity (WHSV)—the ratio of the weight per unit time (for example, g/hr) of the metalalactone (or transition metal-ligand complex) containing solution which comes in contact with a given weight (for example, g) of anionic electrolyte per unit time. While not limited thereto, the WHSV employed, based on the amount of the anionic electrolyte, can be in a range from 0.05 to 100 hr−1, from 0.05 to 50 hr−1, from 0.075 to 50 hr−1, from 0.1 to 25 hr−1, from 0.5 to 10 hr−1, from 1 to 25 hr−1, or from 1 to 5 hr−1.
In the processes disclosed herein, the molar yield of the α,β-unsaturated carboxylic acid, or the salt thereof), based on the metalalactone (or the transition metal-ligand complex) is at least 2%, and more often can be at least 5%, at least 10%, or at least 15%. In particular aspects of this disclosure, the molar yield can be at least 18%, at least 20%, at least 25%, at least 35%, at least 50%, at least 60%, at least 75%, or at least 85%, or at least 90%, or at least 95%, or at least 100%. That is, catalytic formation of the α,β-unsaturated carboxylic acid or the salt thereof can be effected with the disclosed system. For example, the molar yield of the α,β-unsaturated carboxylic acid, or the salt thereof, based on the metalalactone or based on the transition metal precursor compound can be at least 20%, at least 40%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, at least 200%, at least 250%, at least 300%, at least 350%, at least 400%, at least 450%, or at least 500%.
The specific α,β-unsaturated carboxylic acid (or salt thereof) that can be formed or produced using the processes of this disclosure is not particularly limited. Illustrative and non-limiting examples of the α,β-unsaturated carboxylic acid can include acrylic acid, methacrylic acid, 2-ethylacrylic acid, cinnamic acid, and the like, as well as combinations thereof. Illustrative and non-limiting examples of the salt of the α,β-unsaturated carboxylic acid can include sodium acrylate, potassium acrylate, magnesium acrylate, sodium (meth)acrylate, and the like, as well as combinations thereof.
Once formed, the α,β-unsaturated carboxylic acid (or salt thereof) can be purified and/or isolated and/or separated using suitable techniques which can include, but are not limited to, evaporation, distillation, chromatography, crystallization, extraction, washing, decanting, filtering, drying, and the like, including combinations of more than one of these techniques. In an aspect, the process can for performing a metalalactone elimination reaction (or the process for producing an α,β-unsaturated carboxylic acid, or a salt thereof) can further comprise a step of separating or isolating the α,β-unsaturated carboxylic acid (or salt thereof) from other components, e.g., the diluent, the anionic electrolyte, and the like.
The invention is further illustrated by the following examples, which are not to be construed in any way as imposing limitations to the scope of this invention. Various other aspects, embodiments, modifications, and equivalents thereof which, after reading the description herein, can suggest themselves to one of ordinary skill in the art without departing from the spirit of the present invention or the scope of the appended claims.
Unless otherwise noted, all operations were performed under purified nitrogen or vacuum using standard Schlenk or glovebox techniques. Toluene (Honeywell) and tetrahydrofuran (Aldrich) was degassed and dried over activated 4 Å molecular sieves under nitrogen. Sodium tert-butoxide and potassium tert-butoxide were purchased from Sigma-Aldrich and used as received. Phenol-formaldehyde resin was purchased as hollow beads (˜5-127 μm) from Polysciences, Inc. Bis(1,5-cyclooctadiene)nickel(0) and 1,2-Bis(dicyclohexylphosphino)ethane were purchased from Strem and were used as received. (TMEDA)Ni(CH2CH2CO2) was prepared according to literature procedures (Fischer, R; Nestler, B., and Schutz, H. Z. anorg. allg. Chem. 577 (1989) 111-114).
Sodium Phenol-Formaldehyde Resin.
Phenolic resin (phenol-formaldehyde resin) was suspended in a solution of sodium hydroxide in either water or methanol and stirred at 55° C. overnight prior to filtration, and subsequently washed with copious amounts of the solvent in which it was treated. The solid was then dried under vacuum prior to storage under nitrogen.
These examples describe the formation of a crosslinked polyphenoxide resin that is prepared in a non-templated fashion, for comparison with the templated resins. It was believed that these crosslinked polyaromatic resins would be sufficiently insoluble in many commercial diluents to be applicability as a polymeric promoters and cation sources in a fixed bed/column reactor setting. This method further allows for the potential regeneration of the spent solid co-catalyst in both aqueous (for example, sodium hydroxide in water) and/or organic media (for example, sodium alkoxide in toluene).
The following Scheme illustrates the conversion reaction of an olefin and carbon dioxide-derived nickelalactone intermediate that was undertaken to evaluate some crosslinked polyelectrolyte analogues. Reaction conditions for reaction (3) are: 0.10 mmol [Ni], 0.11 mmol diphosphine ligand, 500 mL of toluene, 1.0 g of sodium-treated, crosslinked polyaromatic resin (solid activator). The reactor was equilibrated to 150 psi of ethylene followed by 300 psi of carbon dioxide prior to heating. The yield reported in Table 3 was determined by 1H NMR spectroscopy in a D2O/(CD3)2CO mixture relative to a sorbic acid standard.
The following table describe various examples where commercial polyaromatic resins, which were either further treated with a sodium base under appropriate conditions or are commercially available in the sodium form, were found to be effective in the nickel-mediated synthesis of sodium acrylate from ethylene and carbon dioxide.
AConditions: 0.10 mmol [Ni], 0.11 mmol diphosphine ligand, 500 mL toluene, 1.0 g solid activator (phenol-formaldehyde resin). Reactor was equilibrated to 150 psi ethylene followed by 300 psi carbon dioxide prior to heating. Yield determined by 1H NMR spectroscopy in D2O/(CD3)2CO mixture relative to sorbic acid standard.
BNone detected.
Among other things, Examples 1-3 illustrate the effect that porosity has on base treatment and ultimately on the acrylate yield. For example, the highest acrylate yield was observed with hydroxide base, whereas the lowest (none detected) yield was observed with the bulky t-butoxide base.
In this example, co-monomer phenol compounds are used together with formaldehyde to prepare the crosslinked polyaromatic resins for use as described according to the disclosure. This reaction can also be carried out in a templated fashion in the presence of CaCO3 as the basic particulate template, for example, to form the more porous form of the crosslinked polyphoxide resin described here.
This non-templated resin was prepared using the co-monomer combination of resorcinol (m-dihydroxybenzene) and 2-fluorophenol monomer with formaldehyde, and the resulting resin was sodium-treated (NaOH, dissolved in water or alcohol) to generate the porous crosslinked polyphenol resin, according to the following reaction scheme.
The polyaromatic resin is thought to act as a co-catalyst upon treatment with sodium hydroxide because of what are believed to be sodium aryloxide sites that promote nickelalactone scission. It is noted that increased crosslink density is obtained using longer drying times to remove trapped excess water.
This process can be carried out using the templating process described above in the presence of CaCO3 or MgCO3 to provide a highly porous resin.
These examples describe the formation of a crosslinked polyphenoxide resins of Examples 1-2 using the templating technique described herein. This process not only provided insoluble resins that allowed ease of separation of the α,β-unsaturated carboxylate from the co-catalyst, but also provided the porous crosslinked structure that allowed for high sodium deposition density and facile sodium site access by the metalalactone.
A porous crosslinked polyphenoxide resin was formed by the following process. A CaCO3 basic particulate template is provided, and contacted with at least one phenol compound, formaldehyde, and an aqueous base (NaOH(aq)) under polymerization conditions sufficient to form a templated crosslinked polyphenol resin, in which the crosslinked polyphenol resin formed in the reaction is in contact with the basic particulate template. This templated crosslinked polyphenol resin in contact with the CaCO3 is then contacted with HCl(aq), which removes the basic particulate template and forms the porous crosslinked polyphenol resin in the absence of the template used in its formation. Finally, this porous crosslinked polyphenol resin is then contacted with a metal-containing base such as NaOH in methanol of NaOH(aq) to form a co-catalyst or promoter comprising a porous crosslinked polyphenoxide resin with associated sodium cations.
The porous crosslinked polyphenoxide co-catalyst is used as the solid activator in reaction (3) illustrated above, to convert an olefin and carbon dioxide-derived nickelalactone intermediate to the sodium acrylate, according to the procedure set out in Examples 1-3 and illustrated in the following table.
AConditions: 0.10 mmol [Ni], 0.11 mmol diphosphine ligand, 500 mL toluene, 1.0 g solid activator (phenol-formaldehyde resin). Reactor was equilibrated to 150 psi ethylene followed by 300 psi carbon dioxide prior to heating. Yield determined by 1H NMR spectroscopy in D2O/(CD3)2CO mixture relative to sorbic acid standard.
Even though the yields of acrylate when employing these sodium-treated crosslinked resins may be modest, the examples indicate that the nickel-mediated conversion of carbon dioxide and ethylene to sodium acrylate with sodium treated crosslinked polyaromatic resins can be carried out. Further, the insolubilities of these resins in many commercial solvents will allow for their utility in fixed bed/column configurations.
The invention is described above with reference to numerous aspects and embodiments, and specific examples. Many variations will suggest themselves to those skilled in the art in light of the above detailed description. All such obvious variations are within the full intended scope of the appended claims. Other aspects of the invention can include, but are not limited to, the following aspects. Many aspects are described as “comprising” certain components or steps, but alternatively, can “consist essentially of” or “consist of” those components or steps unless specifically stated otherwise.
Aspect 1. A process for forming a porous crosslinked polyphenoxide resin, the process comprising:
a) in the presence of a basic particulate template, contacting at least one phenol compound, formaldehyde, and an aqueous base under polymerization conditions sufficient to form a templated crosslinked polyphenol resin comprising a crosslinked polyphenol resin in contact with the basic particulate template;
b) contacting the templated crosslinked polyphenol resin with an aqueous acid under pore forming conditions sufficient to remove the basic particulate template and form a porous crosslinked polyphenol resin; and
c) contacting the porous crosslinked polyphenol resin with a metal-containing base to form a promoter comprising a porous crosslinked polyphenoxide resin comprising associated metal cations.
Aspect 2. A process for forming an α,β-unsaturated carboxylic acid or a salt thereof, the process comprising:
a) contacting
b) applying reaction conditions to the reaction mixture suitable to induce a metalalactone elimination reaction to form the α,β-unsaturated carboxylic acid or the salt thereof.
Aspect 3. A process for forming an α,β-unsaturated carboxylic acid or a salt thereof, the process comprising:
Aspect 4. The process according to any one of Aspects 1-3, wherein the porous crosslinked polyphenoxide resin is mesoporous, having an average pore diameter from about 2 nm to about 50 nm.
Aspect 5. The process according to any one of Aspects 1-3, wherein the porous crosslinked polyphenoxide resin is macroporous, having an average pore diameter greater than about 50 nm.
Aspect 6. The process according to any one of Aspects 1-3, wherein the porous crosslinked polyphenoxide resin has an average pore diameter from about 50 nm to about 250 nm.
Aspect 7. The process according to any one of Aspects 1-3, wherein the porous crosslinked polyphenoxide resin comprises a phenoxide-formaldehyde resin, a polyhydroxidearene-formaldehyde resin (such as a resorcinoxide-formaldehyde resin), a polyhydroxidearene- and fluorophenoxide-formaldehyde resin (such as a resorcinoxide- and 2-fluorophenoxide-formaldehyde resin), or combinations thereof.
Aspect 8. The process according to any one of Aspects 1-3, wherein the porous crosslinked polyphenoxide resin comprises a phenoxide-formaldehyde resin, a resorcinoxide-formaldehyde resin, a resorcinoxide- and 2-fluorophenoxide-formaldehyde resin, or any combinations thereof.
Aspect 9. The process according to any one of Aspects 1-3, wherein the porous crosslinked polyphenoxide resin comprises a phenoxide-formaldehyde resin or a resorcinoxide- and 2-fluorophenoxide-formaldehyde resin.
Aspect 10. The process according to any one of Aspects 1-3, wherein the porous crosslinked polyphenoxide resin comprises a phenoxide-formaldehyde resin
Aspect 11. The process according to any one of Aspects 1-10, wherein the associated metal cations comprise any suitable Lewis acidic metal cation or any Lewis acidic metal cation disclosed herein.
Aspect 12. The process according to any one of Aspects 1-10, wherein the associated metal cations are an alkali metal, an alkaline earth metal, or a combination thereof.
Aspect 13. The process according to any one of Aspects 1-10, wherein the associated metal cations are lithium, sodium, potassium, magnesium, calcium, strontium, barium, aluminum, or zinc.
Aspect 14. The process according to any one of Aspects 1-10, wherein the associated metal cations are sodium or potassium.
Aspect 15. The process according to any one of Aspects 2-14, wherein the porous crosslinked polyphenoxide resin is insoluble in the diluent or the reaction mixture.
Aspect 16. The process according to any one of Aspects 2-14, wherein the porous crosslinked polyphenoxide resin is solvent-swellable in the diluent or the reaction mixture.
Aspect 17. The process according to any one of Aspects 1-14, wherein the porous crosslinked polyphenol resin comprises a phenol-formaldehyde resin, a polyhydroxyarene-formaldehyde resin (such as a resorcinol-formaldehyde resin), a polyhydroxyarene- and fluorophenol-formaldehyde resin (such as a resorcinol- and 2-fluorophenol-formaldehyde resin), or combinations thereof.
Aspect 18. The process according to any one of Aspects 1 or 4-14, wherein the basic particulate template has a solubility in water of less than about 0.25 g/L at 25° C.
Aspect 19. The process according to any one of Aspects 1 or 4-14, wherein the basic particulate template has a solubility in water of less than about 0.10 g/L at 25° C.
Aspect 20. The process according to any one of Aspects 1 or 4-14, wherein the basic particulate template has an average particle size from about 2 μm (micrometers) to about 50 μm.
Aspect 21. The process according to any one of Aspects 1 or 4-14, wherein the basic particulate template has an average particle size from about 10 μm (micrometers) to about 25 μm.
Aspect 22. The process according to any one of Aspects 1 or 4-14, wherein the basic particulate template comprises an alkaline earth metal carbonate, phosphate, monohydrogen phosphate, or dihydrogen phosphate.
Aspect 23. The process according to any one of Aspects 1 or 4-14, wherein the basic particulate template comprises magnesium carbonate, calcium carbonate, strontium carbonate, tribasic calcium phosphate, calcium monohydrogen phosphate, or calcium dihydrogen phosphate.
Aspect 24. The process according to any one of Aspects 1 or 4-14, wherein the basic particulate template comprises or is selected from magnesium carbonate or calcium carbonate.
Aspect 25. The process according to any one of Aspects 1 or 4-14, wherein the basic particulate template is calcium carbonate, having an average particle size from about 2 μm (micrometers) to about 50 μm.
Aspect 26. The process according to any one of Aspects 1, 4-14 or 17-25, wherein the aqueous base comprises any suitable aqueous base or any aqueous base disclosed herein.
Aspect 27. The process according to any one of Aspects 1, 4-14 or 17-25, wherein the aqueous base is an alkaline metal hydroxide, such as NaOH or KOH.
Aspect 28. The process according to any one of Aspects 1, 4-14 or 17-25, wherein the aqueous acid comprises any suitable aqueous acid or any aqueous acid disclosed herein.
Aspect 29. The process according to any one of Aspects 1, 4-14 or 17-25, wherein the aqueous acid is a hydrohalic acid such as HCl or HBr.
Aspect 30. The process according to any one of Aspects 2-17, wherein the diluent comprises any suitable non-protic solvent, or any non-protic solvent disclosed herein.
Aspect 31. The process according to any one of Aspects 2-17, wherein the diluent comprises any suitable weakly coordinating or non-coordinating solvent, or any weakly coordinating or non-coordinating solvent disclosed herein.
Aspect 32. The process according to any one of Aspects 2-17, wherein the diluent comprises any suitable aromatic hydrocarbon solvent, or any aromatic hydrocarbon solvent disclosed herein, e.g., benzene, xylene, toluene, etc.
Aspect 33. The process according to any one of Aspects 2-17, wherein the diluent comprises any suitable ether solvent, or any ether solvent disclosed herein, e.g., THF, dimethyl ether, diethyl ether, dibutyl ether, etc.
Aspect 34. The process according to any one of Aspects 2-17, wherein the diluent comprises any suitable carbonyl-containing solvent, or any carbonyl-containing solvent disclosed herein, e.g., ketones, esters, amides, etc. (e.g., acetone, ethyl acetate, N,N-dimethylformamide, etc.).
Aspect 35. The process according to any one of Aspects 2-17, wherein the diluent comprises any suitable halogenated aromatic hydrocarbon solvent, or any halogenated aromatic hydrocarbon solvent disclosed herein, e.g., chlorobenzene, dichlorobenzene, etc.
Aspect 36. The process according to any one of Aspects 2-17, wherein the diluent comprises THF, 2,5-Me2THF, methanol, acetone, toluene, chlorobenzene, pyridine, acetonitrile, or any combination thereof.
Aspect 37. The process according to any one of Aspects 2-17, wherein the diluent comprises carbon dioxide.
Aspect 38. The process according to any one of Aspects 2-17, wherein at least a portion of the diluent comprises the α,β-unsaturated carboxylic acid or the salt thereof, formed in the process.
Aspect 39. The process according to any one of Aspects 3-17 or 30-38, wherein the contacting step further comprises contacting an additive selected from an acid, a base, or a reductant.
Aspect 40. The process according to any one of Aspects 3-17 or 30-39, wherein the contacting step comprises contacting the transition metal precursor compound comprising at least one first ligand with the at least one second ligand.
Aspect 41. The process according to any one of Aspects 3-17 or 30-40, wherein the contacting step comprises contacting (a) the transition metal precursor compound comprising at least one first ligand with (b) the at least one second ligand to form a pre-contacted mixture, followed by contacting the pre-contacted mixture with the remaining components (c)-(f) in any order to provide the reaction mixture.
Aspect 42. The process according to any one of Aspects 2, 4-17, or 30-41, wherein the contacting step comprises contacting the metalalactone compound, the diluent, and the porous crosslinked polyphenoxide resin in any order.
Aspect 43. The process according to any one of Aspects 2, 4-17, or 30-42, wherein the contacting step comprises contacting the metalalactone compound and the diluent to form a first mixture, followed by contacting the first mixture with the porous crosslinked polyphenoxide resin to form the reaction mixture.
Aspect 44. The process according to any one of Aspects 2, 4-17, or 30-43, wherein the contacting step comprises contacting the diluent and the porous crosslinked polyphenoxide resin to form a first mixture, followed by contacting the first mixture with the metalalactone compound to form the reaction mixture.
Aspect 45. The process according to any one of Aspects 2-17 or 30-44, wherein the reaction conditions suitable to form the α,β-unsaturated carboxylic acid or the salt thereof comprise contacting the reaction mixture with any suitable acid, or any acid disclosed herein, e.g., HCl, acetic acid, etc.
Aspect 46. The process according to any one of Aspects 2-17 or 30-45, wherein the reaction conditions suitable to form the α,β-unsaturated carboxylic acid or the salt thereof comprise contacting the reaction mixture with any suitable solvent, or any solvent disclosed herein, e.g., carbonyl-containing solvents such as ketones, esters, amides, etc. (e.g., acetone, ethyl acetate, N,N-dimethylformamide), alcohols, water, etc.
Aspect 47. The process according to any one of Aspects 2-17 or 30-46, wherein the reaction conditions suitable to form the α,β-unsaturated carboxylic acid or the salt thereof comprise heating the reaction mixture to any suitable temperature, or a temperature in any range disclosed herein, e.g., from 50 to 1000° C., from 100 to 800° C., from 150 to 600° C., from 250 to 550° C., etc.
Aspect 48. The process according to any one of Aspects 2-17 or 30-47, wherein the molar yield of the α,β-unsaturated carboxylic acid, or the salt thereof, based on the metalalactone (in those preceding Aspects comprising a metalalactone) or based on the transition metal precursor compound (in those preceding Aspects comprising a transition metal precursor compound) is in any range disclosed herein, e.g., at least 20%, at least 40%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, at least 200%, at least 250%, at least 300%, at least 350%, at least 400%, at least 450%, or at least 500%, etc.
Aspect 49. The process according to any one of Aspects 2-17 or 30-48, wherein the contacting step and/or the applying step is/are conducted at any suitable pressure or at any pressure disclosed herein, e.g., from 5 psig (34 KPa) to 10,000 psig (68,948 KPa), from 45 psig (310 KPa) to 1000 psig (6,895 KPa), etc.
Aspect 50. The process according to any one of Aspects 2-17 or 30-49, wherein the contacting step and/or the applying step is/are conducted at any suitable temperature or at any temperature disclosed herein, e.g., from 0° C. to 250° C., from 0° C. to 95° C., from 15° C. to 70° C., etc.
Aspect 51. The process according to any one of the Aspects 2-17 or 30-50, wherein the contacting step and/or the applying step is conducted at any suitable weight hourly space velocity (WHSV) or any WHSV disclosed herein, e.g., from 0.05 to 50 hr−1, from 1 to 25 hr−1, from 1 to 5 hr−1, etc., based on the amount of the porous crosslinked polyphenoxide resin.
Aspect 52. The process according to any one of Aspects 2-17 or 30-51, wherein the process further comprises a step of isolating the α,β-unsaturated carboxylic acid, or the salt thereof, e.g., using any suitable separation/purification procedure or any separation/purification procedure disclosed herein, e.g., evaporation, distillation, chromatography, etc.
Aspect 53. The process according to any one of Aspects 2-17 or 30-52, wherein the porous crosslinked polyphenoxide resin of the contacting step a) comprises a fixed bed.
Aspect 54. The process according to any one of Aspects 2-17 or 30-52, wherein the porous crosslinked polyphenoxide resin of the contacting step a) is supported onto beads or is used in the absence of a support.
Aspect 55. The process according to any one of Aspects 2-17 or 30-54, wherein the contacting step a) is carried out by mixing/stirring the porous crosslinked polyphenoxide resin in the diluent.
Aspect 56. The process according to any one of Aspects 2-17 or 30-55, wherein the α,β-unsaturated carboxylic acid or the salt thereof comprises any suitable α,β-unsaturated carboxylic acid, or any α,β-unsaturated carboxylic acid disclosed herein, or the salt thereof, e.g., acrylic acid, methacrylic acid, 2-ethylacrylic acid, cinnamic acid, sodium acrylate, potassium acrylate, magnesium acrylate, sodium (meth)acrylate, etc.
Aspect 57. The process according to any one of Aspects 3-17 or 30-56, further comprising a step of contacting the transition metal precursor compound comprising at least one first ligand, the olefin, and carbon dioxide (CO2) to form the metalalactone compound.
Aspect 58. The process according to any one of Aspects 3-17 or 30-56, further comprising a step of contacting the transition metal precursor compound comprising at least one first ligand, at least one second ligand, the olefin, and carbon dioxide (CO2) to form the metalalactone compound.
Aspect 59. The process according to Aspect 58, wherein the metalalactone ligand comprises the at least one first ligand, the at least one second ligand, or a combination thereof.
Aspect 60. The process according to any one of Aspects 3-17 or 30-59, wherein the metalalactone compound comprises the at least one second ligand.
Aspect 61. The process according to any one of Aspects 3-17 or 30-60, wherein the olefin comprises any suitable olefin or any olefin disclosed herein, e.g. ethylene, propylene, butene (e.g., 1-butene), pentene, hexene (e.g., 1-hexene), heptane, octene (e.g., 1-octene), styrene, etc.
Aspect 62. The process according to any one of Aspects 3-17 or 30-61, wherein the olefin is ethylene, and the step of contacting the transition metal precursor compound with the olefin and carbon dioxide (CO2) is conducted using any suitable pressure of ethylene, or any pressure of ethylene disclosed herein, e.g., from 10 psig (69 KPa) to 1,000 psig (6895 KPa), from 25 psig (172 KPa) to 500 psig (3,447 KPa), or from 50 psig (345 KPa) to 300 psig (2,068 KPa), etc.
Aspect 63. The process according to any one of Aspects 3-17 or 30-62, wherein the olefin is ethylene, and the step of contacting the transition metal precursor compound with the olefin and carbon dioxide (CO2) is conducted using a constant addition of the olefin and carbon dioxide to provide the reaction mixture.
Aspect 64. The process according to Aspect 63, wherein the ethylene and carbon dioxide (CO2) are constantly added in an ethylene:CO2 molar ratio of from 3:1 to 1:3, to provide the reaction mixture.
Aspect 65. The process according to any one of Aspects 3-17 or 30-64, wherein the step of contacting the transition metal precursor compound with the olefin and carbon dioxide (CO2) is conducted using any suitable pressure of CO2, or any pressure of CO2 disclosed herein, e.g., from 20 psig (138 KPa) to 2,000 psig (13,790 KPa), from 50 psig (345 KPa) to 750 psig (5,171 KPa), or from 100 psig (689 KPa) to 300 psig (2,068 KPa), etc.
Aspect 66. The process according to any one of Aspects 3-17 or 30-65, further comprising a step of monitoring the concentration of at least one reaction mixture component, at least one elimination reaction product, or a combination thereof.
Aspect 67. The process according to any one of Aspects 2-17 or 30-66, wherein the metal of the metalalactone or the metal of the transition metal precursor compound is a Group 8-11 transition metal.
Aspect 68. The process according to any one of Aspects 2-17 or 30-66, wherein the metal of the metalalactone or the metal of the transition metal precursor compound is Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Pt, or Au.
Aspect 69. The process according to any one of Aspects 2-17 or 30-66, wherein the metal of the metalalactone or the metal of the transition metal precursor compound is Ni, Fe, or Rh.
Aspect 70. The process according to any one of Aspects 2-17 or 30-66, wherein the metal of the metalalactone or the metal of the transition metal precursor compound is Ni.
Aspect 71. The process according to any one of Aspects 2-17 or 30-66, wherein the metalalactone is a nickelalactone, e.g., any suitable nickelalactone or any nickelalactone disclosed herein.
Aspect 72. The process according to any one of Aspects 2-17 or 30-71, wherein any ligand of the metalalactone compound, the first ligand, or the second ligand is any suitable neutral electron donor group and/or Lewis base, or any neutral electron donor group and/or Lewis base disclosed herein.
Aspect 73. The process according to any one of Aspects 2-17 or 30-71, wherein any ligand of the metalalactone compound, the first ligand, or the second ligand is a bidentate ligand.
Aspect 74. The process according to any one of Aspects 2-17 or 30-71, wherein any ligand of the metalalactone compound, the first ligand, or the second ligand comprises at least one of a nitrogen, phosphorus, sulfur, or oxygen heteroatom.
Aspect 75. The process according to any one of Aspects 2-17 or 30-71, wherein any ligand of the metalalactone compound, the first ligand, or the second ligand comprises or is selected from a diphosphine ligand, a diamine ligand, a diene ligand, a diether ligand, or dithioether ligand.
Aspect 76. The process according to any one of Aspects 2-17 or 30-75, further comprising the step of regenerating the porous crosslinked polyphenoxide resin by contacting a porous crosslinked polyphenol resin that is generated from the process with a base comprising a metal cation following the formation of the α,β-unsaturated carboxylic acid or the salt thereof, or by contacting a porous crosslinked polyphenol resin that is generated from the process with a metal-containing salt following the formation of the α,β-unsaturated carboxylic acid or the salt thereof.
Aspect 77. The process according to Aspect 76, further comprising a step of washing the porous crosslinked polyphenoxide resin with a solvent or the diluent following its regeneration.
Aspect 78. The process according to Aspect 76, wherein:
the metal-containing base comprises any suitable base, or any base disclosed herein, e.g., carbonates (e.g., Na2CO3, Cs2CO3, MgCO3), hydroxides (e.g., Mg(OH)2, NaOH), alkoxides (e.g., Al(OiPr)3, Na(OtBu), Mg(OEt)2), sulfates (e.g. Na2SO4), etc.; and
the metal-containing salt comprises sodium chloride, potassium chloride, etc.
Aspect 79. The process according to Aspect 76, wherein the step of regenerating the porous crosslinked polyphenoxide resin is carried out in the absence of an alkoxide, an aryloxide, an amide, an alkylamide, an arylamide, an amine, a hydride, a phosphazene, and/or substituted analogs thereof.
Aspect 80. The process according to Aspect 76, wherein the step of regenerating the porous crosslinked polyphenoxide resin is carried out in the absence of an alkoxide, an aryloxide, a hydride, and/or a phosphazene.
Aspect 81. The process according to Aspect 76, wherein the step of regenerating the porous crosslinked polyphenoxide resin is carried out in the absence of an aryloxide or a metal hydride.
Aspect 82. The process according to Aspect 76, wherein the step of regenerating the porous crosslinked polyphenoxide resin is carried out in the absence of a non-nucleophilic base.
Aspect 83. The process according to Aspect 76, wherein the porous crosslinked polyphenoxide resin is unsupported.
Aspect 84. The process according to Aspect 76, wherein the porous crosslinked polyphenoxide resin is supported.
Aspect 85. The process according to any one of the preceding Aspects, wherein the metalalactone, metalalactone ligand (that is, any ligand of the metalalactone compound other than the metalalactone moiety), transition metal precursor compound, first ligand, second ligand, porous crosslinked polyphenoxide resin, or metal cation is any suitable metalalactone, metalalactone ligand, transition metal precursor compound, first ligand, second ligand, porous crosslinked polyphenoxide resin, or metal cation or is any metalalactone, metalalactone ligand, transition metal precursor compound, first ligand, second ligand, porous crosslinked polyphenoxide resin, or metal cation disclosed herein.
Aspect 86. A porous crosslinked polyphenol resin, the resin comprising
a phenol-formaldehyde resin, a polyhydroxyarene-formaldehyde resin, a polyhydroxyarene- and fluorophenol-formaldehyde resin, or any combination thereof, and having an average particle size from about 2 μm (micrometers) to about 50 μm and an average pore diameter from about 2 nm (nanometers) to about 250 nm.
Aspect 87. A porous crosslinked polyphenoxide resin, the resin comprising
a phenoxide-formaldehyde resin, a polyhydroxidearene-formaldehyde resin, a polyhydroxidearene- and fluorophenoxide-formaldehyde resin, or any combination thereof; and
associated metal cations comprising lithium, sodium, potassium, magnesium, calcium, strontium, barium, aluminum, or zinc;
wherein the porous crosslinked polyphenoxide resin has an average particle size from about 2 μm (micrometers) to about 50 μm and an average pore diameter from about 2 nm (nanometers) to about 250 nm.
This application claims the benefit of priority of U.S. Provisional Patent Application No. 62/519,549, filed Jun. 14, 2017, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62519549 | Jun 2017 | US |
