Patent Application
20240150384
The present invention relates to a series of long shelf life stable metal complexes, their use as (pre)catalysts in the metathesis reaction as well as the process for carrying out the metathesis reaction. More specifically, the present invention relates to a series of organoruthenium compounds which exhibit long shelf life stability and when activated under suitable conditions exhibit high catalytic activity for a wide range of metathesis reactions. This invention also relates to methods of making these compounds. Accordingly, the compounds of this invention find utility as (pre)catalysts for carrying out a variety of olefin metathesis reactions, including ring-opening metathetic polymerization (ROMP), among others.
The metathesis of olefins is an important tool in the organic synthesis (R. H. Grubbs (Ed.), A G Wenzel (Ed.), D. J. O'Leary (Ed.), E. Khosravi (Ed.), Handbook of Olefin Metathesis, 2nd edition, 3 Volumes, 2015, John Wiley & Sons, Inc. 1608 pages]).
Many ruthenium complexes actively catalyzing the olefin metathesis reactions are well known in the art (see, for example, Vougioukalakis, G. C.; Grubbs, R. H. Chem. Rev. 2010, 110, 1746). The third generation complexes (such as Gm-III, Ind-III) were shown to be highly useful (pre)catalysts of the ring-opening metathetic polymerization (ROMP) reaction.
The third-generation catalysts initiate the metathesis reactions very promptly, whereas, in some metathesis applications, such as mold ROMP polymerization, it is advantageous to use a (pre)catalyst that does not initiate the reaction immediately after adding it to the substrate but only after an appropriate initiation by chemical agents, temperature or light. The complexes characterized by delayed initiation are often termed “dormant catalysts” or “latent catalysts” (Monsaert, S.; Vila, A. L.; Drozdzak, R.; Van Der Voort, P.; Verpoort, F., Chem. Soc. Rev., 2009, 38, 3360; R. Drozdzak, N. Nishioka, G. Recher, F. Verpoort, Macromol. Symp. 2010, 293, 1-4). Exemplary “dormant catalysts” are the complexes A-F, as well as the recently obtained P-1 and P-2 (Pietraszuk, C.; Rogalski, S.; Powala, B.; Mitkiewski, M.; Kubicki, M.; Spolnik, G.; Danikiewicz, W.; Wozniak, K.; Pazio, A.; Szadkowska, A.; Kozlowska, A.; Grela, K., Chem. Eur. J, 2012, 18, 6465-6469).
The mold ROMP polymerization allows obtaining finished articles. Dicyclopentadiene is one of the monomers frequently used for the mold polymerization. Polydicyclopentadiene, being obtained by polymerization of dicyclopentadiene, features, inter alia, a low moisture absorption as well as resistance to stress and high temperature. This is why parts of vehicles and specialized containers for the chemical industry are more and more frequently manufactured by the (mold) ROMP polymerization of dicyclopentadiene.
U.S. Pat. No. 9,328,132 B2 addresses some of these deficiencies faced by the art in providing more robust “dormant catalysts” for olefin metathesis reactions, pertinent portions of which are incorporated herein by reference. However, there is still a need for improved “dormant catalysts” which can be activated under desirable ROMP polymerization conditions and based on the intended end applications.
Moreover, there is still a need for latent catalysts which are dormant and can readily be activated with higher activity upon activation.
Accordingly, it is an object of this invention to provide a series of improved “dormant catalysts,” which are stable at ambient temperatures for several months on the shell (as solid) as well as in the mixture with highly reactive monomer(s) (eg. DCPD), and exhibit higher activity only upon activation.
It is also an object of this invention to provide processes for the preparation of such organoruthenium dormant catalysts as disclosed herein.
Other objects and further scope of the applicability of the present invention will become apparent from the detailed description that follows.
From the viewpoint of practical industrial applications, it is of extreme importance that the (pre)catalysts are stable in the presence of oxygen as well as moisture, during both their synthesis, purification, preparation of mixture with monomer, handling, storing, transporting it and also during their use in the metathesis reaction. Development of stable and active (pre)catalysts for metathesis of olefins as reported in the literature allowed to broaden significantly the scope of possible uses of this transformation. Nevertheless, these complexes are still prepared and used in metathesis reactions in atmosphere of inert gas, in dry solvents, since their stability against oxygen and moisture is limited.
Surprisingly, it has now been found that the ruthenium complexes depicted by the formula I are stable in the presence of air and moisture and do not initiate the RO1VIP of active monomers (without activation) for several days to several months. Additionally, the complexes depicted by the formula I show improved activity upon activation.
R2 is selected from the group consisting of (C4-C16)alkenyl, (C6-C14)aryl, (C6-C14)perhaloaryl and (C3-C12)heterocyclyl; or wherein
It should further be noted that all forms of stereoisomers, including without limitation enantiomeric and diastereomeric forms of the compounds of formula (I) are part of this invention.
Following their suitable activation, the complexes of the general formula (I) actively catalyze the metathesis reactions carried out in the presence of air. Moreover, the complexes of the general formula (I) actively catalyze the metathesis reactions only after being activated by chemical agents, and they are very hardly susceptible to thermal activation. These properties enable excellent control of the time of initiating the reaction; such a property is very useful especially for the ROMP-type reactions. It was unexpectedly observed that the complexes of the general formula (I) are extremely stable at ambient conditions and can be stored as such or in combination with a variety of polymerizable olefinic monomers for several days to several months, for example, up to three months or longer.
Further, it has been surprisingly observed that the compounds of formula (I) allowed obtaining polydicyclopentadiene (poly-DCPD) via the ROMP-type reaction carried out in the air, the amount of the (pre)catalyst used being significantly lower than that in the case of using classical complexes. Even an amount of 100 ppm (parts per million, by weight) of the complex according to the invention, that contains an NHC ligand (an N-Heterocyclic Carbene ligand as described hereafter), effectively catalyzes polymerization of dicyclopentadiene (DCPD). This amount corresponds to the mole ratio of the monomer to the (pre)catalyst being of about 65,000:1. Thus, this amount of the (pre)catalyst is less than half of that in the case of the catalyst G (M. Perring, N. B. Bowden Langmuir, 2008, 24, 10480-10487).
Unexpectedly, it has now been found that the thio-derivatives of the general formula (I) as described herein provide unusually high storage stability than when compared to various analogous compounds reported in the art. In spite of their storage stability the compounds of formula (I) exhibit very high catalytic activity as evidenced by the examples provided hereinbelow.
Accordingly, there is provided the compounds of the general formula (I) in accordance with the present invention as described hereinabove as (pre)catalysts for the olefin metathesis reactions.
In some embodiments, the compound of formula (I) is having:
for example
In some other embodiments, the organoruthenium compound within the scope of the formula (I) is of the formula (II):
In some embodiments, the compounds of formula (II) is having:
is of the formula (III):
In yet some other embodiments, the compound of the formula (II) according to this invention is having:
selected from the group consisting of:
and
In some embodiments, any of the known N-heterocyclic carbene compounds can be used as L3 ligands. Non-liming examples of such N-heterocyclic compounds are selected from the group consisting of: pyridine, 4-(N,N-dimethylamino)pyridine, 3-bromopyridine, piperidine, morpholine, pyridazine, pyrimidine, pyrazine, piperazine, 1,2,3-triazole, 1,3,4-triazole, 1,2,3-triazine as well as 1,2,4-triazine. Accordingly, in some embodiments, the compounds of the formulae (I) or (II) according to this invention are having:
Representative non-limiting examples of the compound of the formula (II) may be enumerated as follows:
The compounds of the general formula (I) can be prepared by any of the known procedures in the art. For example, WO2005/082819 A2 discloses a procedure for the preparation of a variety of organometallic compounds similar to that of the compounds of formula (I) but having the bidentate ligands, which involves reacting a suitable precursor with a thallium salt of the desirable bidentate ligand (i.e., a Schiff base) to form the organometallic compounds as described therein. WO2011/009721 A1 discloses a similar approach using silver salts of the Schiff bases to prepare Schiff base based bidentate ligand containing compounds. However, both of these approaches involve utilization of hazardous thallium or expensive silver salts and thus not industrially practical.
Advantageously, it has now been found that the compounds of this invention can be prepared very readily using a variety of easily available alkali metal salts, such as potassium or sodium salts, for example, potassium tert-butoxide, potassium tert-pentoxide, sodium tert-butoxide, sodium tert-pentoxide, and the like.
Scheme I shows the method in accordance with the present invention for the preparation of the compounds of formula (Ib) which is within the scope of the formula (I).
As shown in Scheme I, a suitable organoruthenium precursor compound of formula (Ia) is reacted with a suitable Schiff Base of formula (IIIa) with a suitable alkali metal alkoxide of formula ROAl. In the formulae (Ia) and (IIIa) a, b, Y, Z, L3, R3, R4, R5, R6, R7, R8, R9, R10 and R11 are as defined hereinabove. Xa is halogen selected from chlorine, bromine and iodine; L4 is any suitable neutral ligand including tri(C1-C6)alkylphosphine, tri(C3-C8)cycloalkylphosphine and tri(C6-C14)arylphosphine. Representative ligands of such type include tricyclohexylphosphine and triphenylphosphine without any limitation. R is (C1-C8)alkyl and (C6-C14)aryl, specific examples include methoxide, ethoxide, n-propoxide, iso-propoxide, tert-butoxide, tert-pentoxide, and the like. Al is alkali metal including lithium, sodium, potassium and cesium. The compound of formula (Ia) can be reacted with compound of formula (IIIa) in the presence of ROAl at ambient or super-ambient conditions. Generally, such reactions are carried out in a suitable organic solvents at a temperature from about 20° C. to about 100° C. or higher. In some embodiments such reactions are carried out at a temperature from about 30° C. to about 50° C. Any of the solvents that would dissolve compound of formula (Ia), compound of formula (IIIa) and ROAl can be employed in this reaction. Suitable solvents include toluene, tetrahydrofuran, 1,4-dioxane, dichloromethane, dichloroethane, and mixtures in any combination thereof.
The invention is related also to use of the compounds of the general formula (I) as defined hereinabove as (pre)catalysts in the metathesis reactions. In some embodiments, the compounds of the general formula (I) are used as (pre)catalysts in the reactions of ring-closing metathesis, cross metathesis, homometathesis, alkene-alkyne type metathesis. In some other embodiments, the compounds of the general formula (I) are used as (pre)catalysts in the reaction of ring-opening metathetic polymerization.
The invention concerns also a process for carrying out the metathesis reaction of olefins, wherein at least one olefin is contacted with a compound of the general formula (I) as a (pre)catalyst.
Generally, the metathesis reaction is carried out in an organic solvent. Any of the organic solvents that would allow such polymerization reaction to be carried out can be used. Non-limiting examples of such organic solvents include dichloromethane, dichloroethane, toluene, ethyl acetate and mixtures in any combination thereof.
In some embodiments, the metathesis reaction is carried out without any solvent. In some other embodiments, the metathesis reaction is carried out in the presence of a chemical activator. In general, the chemical activator is a Bronsted or Lewis acid or a halo-derivative of alkane or silane. Non-limiting examples of such activators include hydrogen chloride, chlorotrimethylsilane or p-toluenesulfonic acid.
In some embodiments, the metathesis reaction is a ring-opening metathetic polymerization of dicyclopentadiene.
In yet some other embodiments, the (pre)catalyst of the general formula (I) is added in the solid form to dicyclopentadiene.
In one embodiment, the polymerization reaction is initiated by heating the mixture of dicyclopentadiene and the (pre)catalyst of the general formula (I) to a temperature of 30° C. or higher.
In some embodiments, the starting material contains at least 94 wt. % of dicyclopentadiene.
In another embodiment, the metathesis reaction is carried out at a temperature of from 20 to 120° C. In yet another embodiment, the metathesis reaction is carried out in a period of from 1 minute to 24 hours.
In some embodiments, the metathesis reaction is carried out in the presence of an additive promoting formation of cross bonds.
In one embodiment, the metathesis reaction is carried out using the amount of the (pre)catalyst equal to or less than 1000 ppm.
Throughout the description of the invention and patent claims, if ppm (parts per million) units are used with relation to amount of substance, these are on a weight basis.
Since the inventors do not wish to be bound by any particular mechanism of catalysis, the “(pre)catalyst” term is used to indicate that the compound according to the invention may be either the catalyst itself or a precursor of the active species being the actual catalyst.
The definitions of groups not defined below should have the broadest meanings known in the art.
The term “optionally substituted” means that one or more hydrogen atoms of the group in question have been replaced with the specified groups, provided that such a substitution results in formation of a stable compound.
The term “halo” or “halogen” represents an element selected from F, Cl, Br, I.
The term “alkyl” concerns a saturated, straight-chain or branched-chain hydrocarbon substituent having the specified number of carbon atoms. The non-limiting examples of alkyls are: methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl.
The term “alkoxy” concerns the alkyl substituent, as defined above, bound via an oxygen atom.
The term “perhaloalkyl” represents the alkyl, as defined above, wherein all hydrogens have been replaced with halogen atoms, where the halogen atoms may be identical or different.
The term “cycloalkyl” concerns a saturated mono- or polycyclic hydrocarbon substituent having the specified number of carbon atoms. The non-limiting examples of a cycloalkyl substituent are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl.
The term “alkenyl” concerns a non-cyclic, straight or branched hydrocarbon chain having the specified number of carbon atoms and containing at least one carbon-carbon double bond. The non-limiting examples of alkenyls are: vinyl, allyl, 1-butenyl, 2-butenyl.
The term “aryl” concerns an aromatic mono- or polycyclic hydrocarbon substituent having the specified number of carbon atoms. The non-limiting examples of aryl are: phenyl, mesityl, anthracenyl.
The term “heterocyclyl” concerns aromatic as well as non-aromatic cyclic substituents having the specified number of carbon atoms, wherein one or more carbon atoms have been replaced with a heteroatom such as nitrogen, phosphorus, sulfur, oxygen, provided that there are no two directly connected oxygen or sulfur atoms in the ring. Non-aromatic heterocyclyls can contain from 4 to 10 atoms in the ring, whereas aromatic heterocyclyls must have at least 5 atoms in the ring. The benzo-fused systems also belong to heterocyclyls. The non-limiting examples of non-aromatic heterocyclyls are: pyrrolidinyl, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothienyl, tetrahydropyranyl, dihydropyranyl, tetrahydrothiopyranyl, piperidinyl, morpholinyl, thiomorpholinyl, 2-pyrrolinyl, indolinyl. The non-limiting examples of aromatic heterocyclyls are: pyridinyl, imidazolyl, pyrimidinyl, pyrazolyl, triazolyl, pyrazinyl, furyl, thienyl. The above-mentioned groups may be bound via a carbon atom or a nitrogen atom. For example, the substituent obtained by binding pyrrole may be either pyrrol-1-yl (N-bound) or pyrrol-3-yl (C-bound).
The term “neutral ligand” concerns a substituent having no electrical charge, capable of coordinating to a ruthenium atom. The non-limiting examples of such ligands are: N-heterocyclic carbene ligands, amines, imines, phosphines and oxides thereof, alkyl and aryl phosphites and phosphates, ethers, alkyl and aryl sulfides, coordinated hydrocarbons, haloalkanes and haloarenes. The term “neutral ligand” encompasses also N-heterocyclic compounds; their non-limiting examples are: pyridine, 4-(N,N-dimethylamino)pyridine (DMAP), 3-bromopyridine, piperidine, morpholine, pyridazine, pyrimidine, pyrazine, piperazine, 1,2,3-triazole, 1,3,4-triazole, 1,2,3-triazine and 1,2,4-triazine.
The term “anionic ligand” concerns the substituent capable to co-ordination with a metal center, bearing an electrical charge capable to compensate the charge of the metal center, wherein such a compensation may be complete or partial. The non-limiting examples of anionic ligands are: fluoride, chloride, bromide or iodide anions, carboxylic acid anions, alcohol and phenol anions, thiol and thiophenol anions, (organo)sulfuric and (organo)phosphoric acid anions as well as anions of esters thereof.
The term “carbene” concerns a molecule containing a neutral carbon atom having the valence number of 2 and two non-paired valence electrons. The term “carbene” encompasses also carbene analogues, wherein the carbon atom is replaced with another chemical element such as: boron, silicon, nitrogen, phosphorus, sulfur. The term “carbene” relates particularly to N-heterocyclic carbene (NHC) ligands. The non-limiting examples of the NHC ligands are:
The expression “stereoisomers” as used herein is a general term used for all isomers of the individual molecules that differ only in the orientation of their atoms in space. Typically it includes mirror image isomers that are usually formed due to at least one asymmetric center, (enantiomers). Where the compounds according to the invention possess two or more asymmetric centers, they may additionally exist as diastereomers, also certain individual molecules may exist as geometric isomers (cis/trans). Similarly, certain compounds of this invention may exist in a mixture of two or more structurally distinct forms that are in rapid equilibrium, commonly known as tautomers. Representative examples of tautomers include keto-enol tautomers, phenol-keto tautomers, nitroso-oxime tautomers, imine-enamine tautomers, etc. It is to be understood that all such isomers and mixtures thereof in any proportion are encompassed within the scope of the present invention.
The non-limiting examples of preferred agents promoting formation of cross bonds are tert-butyl peroxide, di-tert-butyl peroxide, and also mixtures thereof.
The following examples describe the procedures used for the preparation of the compounds of this invention and their use in olefin metathesis. The following examples are only intended to illustrate the invention and to explain its particular aspects. The activity of the catalyst (1B) according to the invention was compared to the LatMetSIMes3D3, which structure is presented below:
DCPD used in the following Examples was purchased from commercial sources (Ultrene 99-6 from Cymetech) and contained six mass percent of tricyclopentadiene (TCPD), triphenylphosphine, solution of lithium bis(trimethylsilyl)amide, solution of potassium tert-pentoxide, hydrogen chloride solution in 1,4-dioxane were purchased from commercially sources. All reactions were carried out under argon. The toluene was washed with citric acid, water, dried with 4 Å molecular sieves and deoxidized with argon. The THF was dried with 4 Å molecular sieves and deoxidized with argon.
A toluene solution of lithium bis(trimethylsilyl)amide (1 M, 12 mL, 1.1 eq.) was added to a suspension of SIMesHBF4 (5.1 g, 1.15 eq.) in toluene (82 mL). The resulting mixture was stirred at room temperature for 30 min and then placed in an oil bath heated to a temperature of 80° C. After 10 minutes a compound of formula M10 (10 g, 11.3 mmol, 1 eq.) was added and the mixture was stirred for 10 minutes. Next, (E/Z)-2-(prop-1-en-1-yl)phenol (2.27 g, 1.5 eq.) was added and after additional 30 minutes triphenylphosphine was added (1.48 g, 0.5 eq.). The reaction mixture was stirred at 80° C. for 90 minutes, then cooled down to room temperature and filtered through a short pad of silica gel. The silica gel pad was washed with toluene. The crude product was purified by crystallization and recrystallization from dichloromethane/n-heptane mixture, green solid, 4.2 g, 46% yield.
A toluene solution of potassium tert-pentoxide (1.7 M, 1.74 mL, 1.2 eq.) was added to a solution of imine 1 (0.72 g, 1.2 eq.) in tetrahydrofuran (23 mL) and the resulting mixture was stirred at room temperature for 30 min. After that, LatMetSIMesPPh3 (2 g, 2.47 mmol, 1 eq.) was added and the reaction was stirred at 41° C. for 45 min. The reaction mixture was filtered through a short pad of celite. The celite pad was washed with THF. The solvents were evaporated to dryness and the crude product was crystallized from a dichloromethane/methanol mixture, black crystals, 0.95 g, 51% yield. The compound was characterized by 1H and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=13.94 (s, 1H), 8.46 (s, 1H), 7.50 (d, 1H), 7.36 (ddd, 1H), 7.33 (dd, 1H), 7.18-7.14 (m, 1H), 7.13 (dd, 1H), 7.05 (ddd, 1H), 6.94 (ddd, 1H), 6.77 (s, 2H), 6.64 (s, 2H), 6.54-6.47 (m, 2H), 6.44 (ddd, 1H), 6.26 (d, 1H), 6.20 (ddd, 1H), 3.87-3.75 (m, 4H), 2.30 (s, 6H), 2.21 (s, 6H), 2.07 (s, 6H), 1.23 (s, 3H).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=297.4, 215.4, 178.2, 170.7, 158.2, 152.9, 151.7, 139.6, 138.0, 137.8, 137.5, 136.8, 133.2, 132.9, 130.7, 129.6, 129.4, 129.3, 126.1, 125.5, 124.4, 122.4, 118.6, 118.2, 113.4, 112.2, 52.8, 23.1, 21.4, 18.7, 18.6.
A toluene solution of potassium tert-pentoxide (1.7 M, 5.23 mL, 1.2 eq.) was added to a solution of imine 2 (2.41 g, 1.2 eq.) in tetrahydrofuran (68.8 mL) and the resulting mixture was stirred at room temperature for 30 minutes. After that, LatMetSIMesPPh3 (6 g, 7.4 mmol, 1 eq.) was added and the reaction was stirred at 41° C. for 1 hour. The reaction mixture was filtered through a short pad of celite. The celite pad was washed with THF. The solvents were evaporated to dryness and the crude product was crystallized from a dichloromethane/methanol mixture, black crystals, 4.76 g, 82% yield. The compound was characterized by 1H and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=13.89 (s, 1H), 7.59 (s, 1H), 7.29 (dd, 1H), 7.22 (ddd, 1H), 7.00-6.90 (m, 4H), 6.81 (s, 2H), 6.77 (dd, 1H), 6.68 (ddd, 1H), 6.52 (s, 2H), 6.37-6.31 (m, 2H), 6.09 (d, 1H), 6.01 (ddd, 1H), 3.77-3.67 (m, 2H), 3.60-3.50 (m, 2H), 2.37 (s, 6H), 2.35 (s, 6H), 2.13 (s, 6H), 0.87 (d, 3H), 0.67 (hept, 1H), 0.26 (d, 3H).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=292.0, 207.8, 181.3, 172.7, 161.7, 158.4, 152.1, 138.1, 137.9, 137.8, 137.3, 135.7, 135.6, 133.8, 131.8, 129.5, 129.4, 129.2, 128.5, 125.3, 124.8, 123.7, 122.6, 118.7, 115.8, 111.9, 111.6, 52.8, 41.9, 23.5, 21.3, 19.2, 18.7, 18.4.
A toluene solution of potassium tert-pentoxide (1.7 M, 0.44 mL, 1.2 eq.) was added to a solution of imine 3 (0.23 g, 1.2 eq.) in tetrahydrofuran (11.9 mL) and the resulting mixture was stirred at room temperature for 30 minutes. After that, LatMetSIMesPPh3 (0.5 g, 0.62 mmol, 1 eq.) was added and the reaction was stirred at 41° C. for 1 hour. The reaction mixture was filtered through a short pad of celite. The celite pad was washed with THF. The solvents were evaporated to dryness and the crude product was crystallized from a dichloromethane/methanol mixture, black crystals, 0.23 g, 45% yield. The compound was characterized by 1H and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=13.86 (s, 1H), 7.59 (s, 1H), 7.28 (dd, 1H), 7.21 (ddd, 1H), 6.98-6.88 (m, 4H), 6.78 (s, 2H), 6.75 (dd, 1H), 6.67 (ddd, 1H), 6.53 (s, 2H), 6.34 (ddd, 1H), 6.31 (dd, 1H), 6.08 (d, 1H), 6.00 (ddd, 1H), 3.75-3.65 (m, 2H), 3.58-3.48 (m, 2H), 2.36 (s, 6H), 2.35 (s, 6H), 2.15 (s, 6H), 1.71-1.63 (m, 1H), 1.62-1.55 (m, 1H), 1.55-1.48 (m, 1H), 1.34-1.23 (m, 1H), 1.22-1.12 (m, 1H), 1.03 (qt, 1H), 0.88 (qd, 1H), 0.77 (qt, 1H), 0.53-0.41 (m, 2H), -0.25 (qd, 1H).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=291.7, 208.0, 181.2, 172.7, 161.5, 158.4, 152.1, 138.2, 137.9, 137.7, 137.3, 136.1, 135.5, 133.7, 131.8, 129.4 (2×C), 129.0, 128.8, 125.3, 124.6, 123.7, 122.6, 118.6, 115.8, 111.8, 111.6, 52.9, 49.8, 33.9, 29.5, 27.2, 27.0, 25.7, 21.5, 18.7, 18.4.
A toluene solution of potassium tert-pentoxide (1.7 M, 0.44 mL, 1.2 eq.) was added to a solution of imine 4 (0.22 g, 1.2 eq.) in tetrahydrofuran (13.9 mL) and the resulting mixture was stirred at room temperature for 30 minutes. After that, LatMetSIMesPPh3 (0.5 g, 0.62 mmol, 1 eq.) was added and the reaction was stirred at 41° C. for 1 hour. The reaction mixture was filtered through a short pad of celite. The celite pad was washed with THF. The solvents were evaporated to dryness and the crude product was crystallized from a dichloromethane/methanol mixture, brown powder, 0.20 g, 40% yield. The compound was characterized by 1H and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=14.11 (s, 1H), 9.52 (s, 1H), 8.07 (d, 1H), 7.67 (d, 1H), 7.59 (d, 1H), 7.50-7.38 (m, 3H), 7.32 (dd, 1H), 7.19 (ddd, 1H), 7.15 (ddd, 1H), 6.94 (ddd, 1H), 6.72-6.61 (m, 5H), 6.58 (dd, 1H), 6.26 (d, 1H), 6.21 (ddd, 1H), 3.87-3.74 (m, 4H), 2.21 (s, 6H), 2.19 (s, 6H), 2.08 (s, 6H), 1.26 (s, 3H).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=299.1, 214.9, 178.4, 171.2, 153.0, 152.9, 151.2, 139.5, 137.9, 137.7, 137.3, 136.8, 133.4, 133.0, 132.6, 130.7, 129.5, 129.4, 129.3 (2×C), 127.8, 127.3, 125.7, 125.2, 121.7, 119.4, 118.8, 118.5, 112.2, 111.4, 52.7, 22.8, 21.3, 18.7, 18.6.
A toluene solution of potassium tert-pentoxide (1.7 M, 139 mL, 1.05 eq.) was added to a suspension of SIPrHBF4 (113 g, 1.05 eq.) in toluene (2050 mL). The resulting mixture was stirred at room temperature for 30 minutes and then placed in an oil bath heated to a temperature of 85° C. After 20 minutes M10 (200 g, 226 mmol, 1 eq.) was added followed by an addition of toluene (50 mL). The mixture was stirred for 30 minutes. After that, (E/Z)-2-(prop-1-en-1-yl)phenol (45.4 g, 1.5 eq.) in toluene (50 mL) was added followed by an addition of triphenylphosphine (59.2 g, 1 eq.). The reaction mixture was stirred at 85° C. for 90 minutes, then cooled down to room temperature and filtered through a short pad of silica. The silica gel pad was washed with toluene. The solvents were evaporated to dryness and the crude product was crystallized from a dichloromethane/methanol mixture, 38.6 g, 19% yield.
A toluene solution of potassium tert-pentoxide (1.7 M, 22 mL, 1.21 eq.) was added to a solution of imine 1 (9.18 g, 1.22 eq.) in tetrahydrofuran (288 mL) and the resulting mixture was stirred at room temperature for 30 minutes. After that, LatMetSIPrPPh3 (27.73 g, 31 mmol, 1 eq.) was added and the reaction was stirred at 61° C. for one hour, then cooled down to room temperature and filtered through a short pad of celite. The celite pad was washed with tetrahydrofuran and dichloromethane. The solvents were evaporated to dryness and the crude product was crystallized from a dichloromethane/n-heptane mixture yielded 1B as a mixture of diastereomers, brown powder, 27.05 g, 104% yield of crude product. The brown powder was dissolved in dichloromethane (500 mL). Then, methanol (150 mL) was added portion-wise over a period of 5 hours to a stirring brown solution. The resulting solution was stirred at room temperature for one hour and filtered through a filter paper. Dichloromethane was slowly evaporated to yield 1B as a single diastereomer, black crystals. The product was recrystallized from a dichloromethane/methanol mixture, black crystals, 20.82 g, 80% yield. The compound was characterized by 1H and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=15.12 (s, 1H), 8.55 (s, 1H), 7.59 (d, 1H), 7.36 (ddd, 1H), 7.15-7.06 (m, 3H), 7.06-6.98 (m, 4H), 6.96 (dd, 1H), 6.94-6.88 (m, 3H), 6.65 (ddd, 1H), 6.36 (d, 1H), 6.29 (ddd, 1H), 6.24 (ddd, 1H), 5.71 (d, 1H), 4.16-4.06 (m, 2H), 3.93-3.82 (m, 2H), 3.60 (hept, 2H), 3.26 (hept, 2H), 1.21 (d, 6H), 1.17 (d, 6H), 1.11 (s, 3H), 1.00 (d, 6H), 0.67 (d, 6H).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=294.1, 215.5, 179.6, 171.6, 161.6, 153.7, 152.2, 146.8, 146.7, 141.1, 135.8, 133.0, 132.5, 132.2, 132.1, 130.8, 128.5, 126.2, 125.3, 124.8, 124.6, 124.3, 122.1, 118.9, 117.9, 113.1, 112.3, 56.0, 28.9, 28.7, 26.6, 26.5, 23.5, 23.2, 21.1.
A compound of this invention was used to show the shelf life stability of the compounds of this invention when compared with an organoruthenium compound disclosed in the art as shown in the Comparative Example 1 below.
A compound of Example 5, compound 1B, was used in this study: 1B (14.93 mg, 40 mol ppm) was dissolved in 60 mL of Ultrene 99-6, which was designated as formulation A. The resulting solution was stored under argon at room temperature. The shelf life of formulation A was monitored in a test reaction with a freshly prepared formulation B containing HCl (200 mol ppm) once every two weeks.
A test procedure:
A solution of hydrogen chloride (4 M solution in 1,4-dioxane, 1.85 μL, 200 mol ppm) in 5 mL of Ultrene 99-6 was prepared, and was designated as formulation B. The formulation B as formed was added to 5 mL of freshly prepared formulation A (1.244 mg, 40 mol ppm of 1B). The final, reactive formulation contained 20 mol ppm of 1B and 100 mol ppm of HCl. The results are summarized in Table 1.
The formulation A was then stored at room temperature for 30 weeks. After which time a freshly prepared formulation B (5 mL of Ultrene 99-6 with hydrogen chloride; 4 M solution in 1,4-dioxane, 1.85 μL, 200 mol ppm) was added to 5 mL of formulation A (1.244 mg, 40 mol ppm of 1B). The final, reactive formulation contained 20 mol ppm of 1B and 100 mol ppm of HCl. The results are summarized in Table 2.
It is evident from the data presented in Tables 1 and 2, the catalytic activity of the compound of this invention, i.e., 1B is not negatively affected even after storing at room temperature for 30 weeks. In fact, the solution of formulation A is even more active after 30 weeks than it was immediately after it was prepared.
LatMetSIMes3D3 (14.11 mg, 40 mol ppm) was dissolved in 60 mL of Ultrene 99-6 giving formulation A. The resulting solution was stored under argon at room temperature. The shelf life of formulation A was monitored in a test reaction with a freshly prepared formulation B containing HCl (200 mol ppm) once every two weeks.
A test procedure:
5 mL of Ultrene 99-6 with hydrogen chloride (4 M solution in 1,4-dioxane, 1.85 μL, 200 mol ppm) was prepared and designated as formulation B. Formulation B was added to 5 mL of formulation A (1.176 mg, 40 mol ppm of 1B). The final, reactive formulation contained 20 mol ppm of LatMetSIMes3D3 and 100 mol ppm of HCl. The results are summarized in Table 3.
5 mL of fresh formulation B was prepared as described above. Formulation B was added to formulation A (5 mL, 40 mol ppm of LatMetSIMes3D3) which was stored for 2 weeks. The final, reactive concentration contained 20 mol ppm of LatMetSIMes3D3 and 100 mol ppm of HCl. The reactive formulation was gelled and no peak exotherm was observed which was the result of partial catalyst decomposition.
A toluene solution of potassium tert-pentoxide (1.7 M, 4.26 mL, 1.2 eq.) was added to a solution of imine 5 (2.27 g, 1.2 eq.) in 1,4-dioxane (56.0 mL) and the resulting mixture was stirred at room temperature for 30 minutes. After that, LatMetSIMesPCy3 (5 g, 6.0 mmol, 1 eq.) was added and the reaction was stirred at 95° C. for 2 hours. The reaction mixture was cooled down to room temperature and filtered through a short pad of celite. The celite pad was washed with 1,4-dioxane and dichloromethane. The solvents were evaporated to dryness and the crude product was crystallized from a dichloromethane/n-heptane mixture yielded 5A as a mixture of diastereomers, brown powder, 4.16 g, 84% yield of crude product. The product was recrystallized from a dichloromethane/methanol mixture yielded pure 5A as a mixture of diastereomers, deep brown or black crystals 3.05 g, 61% yield. The pure mixture of diastereomers was dissolved in dichloromethane (30 mL). Then, methanol (45 mL) was added slowly. The resulting solution was stirred at room temperature overnight. The solvents were evaporated slowly to dryness yielded 5A as a single diastereomer, deep brown or black crystals, 3.01 g, 61% yield. The compound was characterized by 1H and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=14.07 (s, 1H), 8.36 (s, 1H), 7.62 (d, 1H), 7.45-7.41 (m, 1H), 7.40 (d, 1H), 7.19-7.14 (m, 1H), 6.97-6.89 (m, 2H), 6.84 (d, 1H), 6.76-6.71 (m, 2H), 6.69-6.62 (m, 3H), 6.38 (d, 1H), 6.26 (d, 1H), 6.24-6.19 (m, 1H), 3.89-3.67 (m, 4H), 2.79 (hept, 1H), 2.28 (s, 6H), 2.19 (s, 6H), 2.07-1.99 (m, 7H), 1.28-1.22 (m, 6H), 0.49 (d, 3H), 0.30 (d, 3H).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=296.1, 214.7, 177.9, 169.5, 157.6, 152.9, 152.8, 139.5, 138.1, 137.7, 137.6, 133.1, 133.1, 132.4, 132.3, 131.9, 130.5, 129.6, 129.4, 128.9, 125.5, 125.1, 124.1, 121.8, 118.6, 118.2, 112.0, 52.6, 45.2, 33.3, 24.6, 24.4, 22.4, 21.4, 20.6, 19.0, 18.7.
A toluene solution of potassium tert-pentoxide (1.7 M, 4.26 mL, 1.2 eq.) was added to a solution of imine 6 (2.36 g, 1.2 eq.) in 1,4-dioxane (56.0 mL) and the resulting mixture was stirred at room temperature for 30 minutes. After that, LatMetSIMesPCy3 (5 g, 6.0 mmol, 1 eq.) was added and the reaction was stirred at 95° C. for 2 hours. The reaction mixture was cooled down to room temperature and filtered through a short pad of celite. The celite pad was washed with 1,4-dioxane and dichloromethane. The solvents were evaporated to dryness and the crude product was crystallized from a dichloromethane/n-heptane mixture yielded 6A as a mixture of diastereomers, brown powder, 4.74 g, 94% yield of crude product. The brown powder was dissolved in a mixture of dichloromethane (30 mL) and methanol (150 mL). The resulting solution was stirred at room temperature overnight. Dichloromethane was slowly evaporated to yield 6A as a single diastereomer, black crystals, 3.18 g, 63% yield. The compound was characterized by 1H and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=14.14 (s, 1H), 8.41 (s, 1H), 7.39 (ddd, 1H), 7.33 (dd, 1H), 7.22-7.14 (m, 1H), 7.08-6.99 (m, 2H), 6.95 (ddd, 1H), 6.72 (d, 4H), 6.61 (dd, 1H), 6.46 (d, 1H), 6.40 (ddd, 1H), 6.30 (d, 1H), 6.23 (ddd, 1H), 3.88-3.70 (m, 4H), 2.29 (s, 6H), 2.19 (s, 6H), 2.09 (s, 6H), 1.76-1.58 (m, 1H), 1.56-1.44 (m, 2H), 1.38-1.28 (m, 1H), 1.03 (qt, 1H), 0.94 (qt, 1H), 0.79 (qt, 1H), 0.60 (qd, 1H), 0.40-0.31 (m, 1H), 0.26-0.08 (m, 2H).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=297.0, 296.9, 214.7, 178.2, 170.5, 158.3, 153.0, 152.0, 139.5, 138.0, 137.6, 136.8, 133.2, 133.0, 132.8, 131.5, 129.5, 129.2, 129.1, 126.1, 125.8, 124.3, 122.2, 118.8, 118.2, 113.2, 112.5, 52.6, 48.5, 36.4, 32.8, 32.2, 26.8, 26.8, 26.5, 21.4, 18.8, 18.7.
The structure of complex 1B, as illustrated below, was determined by X-ray crystallographic analysis. Crystals of 1B for this analysis were grown from a dichloromethane/n-heptane solution.
SIMesHBF4 (7.81 g, 19.8 mmol, 1.1 eq.) was placed under argon in a round bottomed flask. Toluene (160 mL) was added and the resulted suspension was heated up to 80° C. Next, LiHMDS (1 M in toluene, 19.8 mL, 1.1 eq.) was added and the mixture was stirred for 3 minutes before an addition of M10 (15.96 g, 18.0 mmol, 1 eq.). After 15 min full conversion of M10 was observed on TLC plate (AcOEt/c-C6H12, 1:9, v/v). The temperature was raised to 110° C. and (E/Z)-2-(prop-1-en-1-yl)-6-isopropylphenol (7.29 g, 36.0 mmol, 2 eq.) was added. The resulted mixture was stirred for 20 min before tricyclohexylphosphine (5.55 g, 19.8 mmol, 1.1 eq.) was added. The stirring was continued for additional 2.5 hours. After that time, the reaction mixture was cooled down to room temperature and was filtered through a short pad of celite. The filtrate was concentrated and the crude product was purified by column chromatography (c-C6H12 to c-C6H12/AcOEt, 98:2, v/v). Solvents were removed and the crude product was crystalized two times from a dichloromethane/methanol mixture, green solid, 5.26 g, 33% yield. The compound was characterized by 1H, 31P and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=15.72 (d, J=1.3 Hz, 1H), 7.09 (bs, 1H), 7.01 (bs, 1H), 6.67 (bs, 1H), 6.93-6.89 (dd, J=7.0, 1.6 Hz, 1H), 6.27 (dd, J=7.7, 1.7 Hz, 2H), 6.22-6.20 (m, 1H), 3.98 (ddd, J=11.5, 9.0, 7.2 Hz, 1H), 3.81-3.68 (m, 3H), 3.60 (ddd, J=10.4, 9.2, 7.2 Hz, 1H), 2.67 (s, 3H), 2.53 (d, J=9.1 Hz, 6H), 2.35 (s, 3H), 2.28 (s, 3H), 1.67-1.64 (m, 3H), 1.62-1.54 (m, 9H), 1.44-1.41 (m, 3H), 1.19-1.16 (m, 9H), 1.10-1.00 (m, 9H), 0.97-0.94 (m, 3H), 0.84 (qt, J=12.4, 2.8 Hz, 3H), 0.67 (qt, J=12.8, 3.0 Hz, 3H).
31P NMR (CD2Cl2, 240 MHz): δ [ppm]=28.05.
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=281.4, 222.5, 222.0, 178.1, 147.9, 139.9, 139.5, 138.9, 137.7, 137.6, 137.5, 137.1, 135.9, 134.7, 130.4, 130.3, 129.9, 129.1, 125.8, 120.5, 111.7, 51.8, 51.7, 32.3, 32.2, 29.4, 29.1, 28.2, 28.2, 28.1, 28.1, 27.1, 25.8, 24.0, 23.8, 21.7, 21.3, 19.6, 19.2, 18.8, 16.9.
A toluene solution of potassium tert-pentoxide (1.7 M, 0.34 mL, 1.2 eq.) was added to a solution of imine 2 (0.157 g, 1.2 eq.) in 1,4-dioxane (5 mL) and the resulting mixture was stirred at room temperature for 30 minutes. After that, LatMet(6-iPr)SIMesPCy3 (0.42 g, 0.48 mmol, 1 eq.) was added and the reaction was stirred at 95° C. for 3 hours. The reaction mixture was filtered through a short pad of celite. The celite pad was washed with 1,4-dioxane. The solvents were evaporated to dryness. Crude product was dissolved in dichloromethane (3 mL) and heptane (15 mL). Brownish solid was filtered off and rejected. The filtrate was concentrated to dryness and crude product was crystalized from a dichloromethane/methanol mixture. Dark-brown crystals were filtered off, washed with methanol and dried, 0.19 g, 40% yield. The compound was characterized by 1H and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=13.68 (s, 1H); 7.56 (s, 1H); 7.28-7.25 (m, 1H); 7.21-7.16 (m, 1H); 6.98-6.86 (m, 4H); 6.76-6.69 (m, 3H); 6.55-6.49 (m, 3H); 6.31-6.26 (m, 1H); 6.19-6.14 (m, 1H); 5.96-5.91 (m, 1H); 3.76-3.66 (m, 2H); 3.58-3.48 (m, 2H); 2.82 (sept, 1H, J=7.2 Hz); 2.39 (s, 6H); 2.37 (s, 6H); 2.10 (s, 6H); 1.05 (d, 3H, J=7.2 Hz); 0.86 (d, 3H, J=7.2 Hz); 0.63 (d, 3H, J=7.2 Hz); 0.55 (sept, 1H, J=7.2 Hz); 0.35 (d, 3H, J=7.2 Hz).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=289.1, 208.4, 179.2, 172.8, 160.9, 157.4, 151.2, 138.0, 137.7, 137.1, 136.8, 136.7, 135.3, 134.9, 133.0, 131.1, 129.2, 128.7, 128.5, 128.0, 124.4, 124.0, 123.9, 122.7, 121.2, 115.1, 111.0, 110.7, 52.3, 25.9, 24.3, 22.9, 20.8, 20.2, 18.6, 18.3, 17.8.
A toluene solution of potassium tert-pentoxide (1.7 M, 0.81 mL, 1.2 eq.) was added to a solution of imine 1 (0.33 g, 1.2 eq.) in 1,4-dioxane (11 mL) and the resulting mixture was stirred at room temperature for 30 minutes. After that, LatMet(4-NO2)SIMesPCy3 (1.0 g, 1.14 mmol, 1 eq.) was added and the reaction was stirred at 95° C. for 1.5 hour. The reaction mixture was cooled down to room temperature and concentrated to 40% of original volume. Crude product was filtered off, washed with toluene and methanol and recrystallized from a dichloromethane/methanol mixture, dark-green crystals, 0.72 g, 79% yield. The product was characterized by 1H and 13C NMR.
Two diastereomers were observed. The minor diastereomer with the characteristic benzylidene proton signal at 14.57 ppm and the major diastereomer (95%) with the characteristic benzylidene proton signal at 14.02 ppm.
Peaks of the major diastereomer in 1H and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=14.02 (s, 1H); 8.52 (s, 1H); 7.87-7.81 (m, 1H); 7.50-7.42 (m, 2H); 7.41-7.34 (m, 2H); 7.25-7.17 (m, 2H); 7.14-7.08 (m, 1H); 6.84 (s, 2H); 6.63 (s, 2H); 6.59-6.50 (m, 2H); 6.17 (d, 1H, J=9.0 Hz); 3.90-3.78 (m, 4H); 2.33 (s, 6H); 2.21 (s, 6H); 2.08 (s, 6H); 1.25 (s, 3H).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=295.5, 295.4, 211.6, 181.4, 170.6, 158.9, 151.3, 150.3, 138.9, 138.4, 137.9, 137.5, 136.9, 134.9, 133.8, 131.4, 130.6, 129.6, 129.5, 129.5, 127.6, 126.7, 123.9, 122.2, 120.2, 118.2, 117.0, 114.3, 52.5, 24.9, 21.4, 18.4, 18.3.
Toluene (30 mL) was added to the G2 (3 g, 3.53 mmol, 1 eq.) placed in a round bottomed flask. Next, (E/Z)-2-(prop-1-en-1-yl)-4-methoxyphenol (0.75 g, 4.59 mmol, 1.3 eq.) and tricyclohexylphosphine (1.29 g, 4.59 mmol, 1.3 eq.) were added. The reaction mixture was stirred at 80° C. for 6 hours and then cooled down to room temperature. Half of the toluene was removed on rotavapor and heptane (15 mL) was added. The sticky solid was filtered off on Celite and rejected. The filtrate was evaporated to dryness and a solid residue was further dried on high vacuum. The crude product was crystalized from a dichloromethane/methanol mixture, olive-green solid, 2.6 g, 86% yield. The compound was characterized by 1H and 31P NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=15.59 (s, 1H), 7.06 (s, 1H), 6.69 (d, J=8.4 Hz, 2H); 6.83-6.75 (m, 1H); 6.56 (d, J=9.0 Hz, 1H); 6.34 (s, 1H); 5.96 (d, J=3 Hz, 1H); 4.02-3.93 (m, 1H); 3.83-3.69 (m, 2H); 3.67 (s, 3H); 3.65-3.58 (m, 1H); 2.61 (s, 3H); 2.53 (s, 3H); 2.51 (s, 3H); 2.34 (s, 3H); 2.28 (s, 3H); 1.72-1.38 (m, 15H); 1.29 (s, 3H); 1.14-0.97 (m, 9H), 0.97-0.66 (m, 9H).
31P NMR (CD2Cl2, 240 MHz): δ [ppm]=28.45.
A toluene solution of potassium tert-pentoxide (1.7 M, 0.49 mL, 1.2 eq.) was added to a solution of imine 2 (0.23 g, 1.2 eq.) in 1,4-dioxane (7 mL) and the resulting mixture was stirred at room temperature for 30 minutes. After that, LatMet(4-OMe)SIMesPCy3 (0.6 g, 0.7 mmol, 1 eq.) was added and the reaction was stirred at 95° C. for 5 hours. The reaction mixture was filtered through a short pad of celite. The celite pad was washed with 1,4-dioxane. The solvents were evaporated to dryness. Crude product was dissolved in dichloromethane (3 mL) and heptane (15 mL) was added. Brownish solid was filtered off and rejected. The filtrate was concentrated to ca. 10 mL and stored overnight in a fridge. Dark-brown crystals were filtered off and dried, 0.53 g, 93% yield. The compound was characterized by 1H and 13C NMR. Two diastereomers of the product were observed. Only characteristic benzylidene protons and carbene carbons signals are provided:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=13.67 (s, 0.93H), 13.60 (s, 1.06H).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=292.3, 287.4.
A toluene solution of potassium tert-pentoxide (1.7 M, 0.49 mL, 1.2 eq.) was added to a solution of imine 1 (0.20 g, 1.2 eq.) in 1,4-dioxane (7 mL) and the resulting mixture was stirred at room temperature for 30 minutes. After that, LatMet(4-OMe)SIMesPCy3 (0.6 g, 0.7 mmol, 1 eq.) was added and the reaction was stirred at 95° C. for 3.5 hours. The reaction mixture was filtered through a short pad of celite. The celite pad was washed with 1,4-dioxane. The solvents were evaporated to dryness. Crude product was dissolved in dichloromethane (3 mL) and filtered through Celite again. Heptane (15 ml) was added and dichloromethane was removed on a rotavapor. Crude product was filtered off, washed with heptane and recrystallized from a dichloromethane/methanol mixture, dark-brown crystals, 0.44 g, 80% yield. The compound was characterized by 1H and 13C NMR:
1H NMR (CD2Cl2, 5.32 ppm; 600 MHz): δ [ppm]=13.63 (s, 1H), 8.45 (s, 1H), 7.49 (d, 1H), 7.38-7.31 (m, 2H), 7.19-7.10 (m, 2H), 7.05 (ddd, 1H), 6.79 (bs, 2H), 6.73 (dd, 1H), 6.65 (bs, 2H), 6.50 (d, 1H), 6.44 (ddd, 1H), 6.20 (d, 1H), 6.00 (d, 1H), 3.87-3.75 (m, 4H), 3.66 (s, 3H), 2.30 (s, 6H), 2.21 (s, 6H), 2.08 (s, 6H), 1.24 (s, 3H).
13C NMR (CD2Cl2, 54.00 ppm; 150 MHz): δ [ppm]=293.4, 215.4, 174.2, 170.4, 157.9, 151.5, 150.9, 148.5, 139.6, 138.0, 137.7, 137.5, 136.8, 133.1, 132.9, 130.6, 129.4, 129.3, 129.1, 126.0, 124.2, 122.8, 122.3, 118.4, 118.1, 113.3, 106.3, 56.2, 52.6, 22.9, 21.4, 18.6, 18.5.
Although the invention has been illustrated by certain of the preceding examples, it is not to be construed as being limited thereby; but rather, the invention encompasses the generic area as hereinbefore disclosed. Various modifications and embodiments can be made without departing from the spirit and scope thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21154875.5 | Feb 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2022/050893 | 2/2/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63144610 | Feb 2021 | US |
