Metal-mediated cross-coupling with ring-metalated porphyrins

FIELD OF THE INVENTION
This invention relates to substituted porphyrins and to techniques and intermediates useful in preparing substituted porphyrins. The invention also relates to polymers and macromolecules prepared from the porphyrins, and to new and improved uses for the porphyrins and their polymers.
BACKGROUND OF THE INVENTION
Porphyrins are derivatives of porphine, a conjugated cyclic structure of four pyrrole rings linked through their 2- and 5-positions by methine bridges. Porphyrins can be covalently attached to other molecules. The electronic features of the porphyrin ring system can be altered by the attachment of one or more substituents. The term "porphyrin" includes derivatives wherein a metal atom is inserted into the ring system, as well as molecular systems in which ligands are attached to the metal. The substituents, as well as the overall porphyrin structure, can be neutral, positively charged, or negatively charged.
Numerous porphyrins have been isolated from natural sources. Notable porphyrin-containing natural products include hemoglobin, the chlorophylls, and vitamin B.sub.12. Also, many porphyrins have been synthesized in the laboratory, typically through condensation of suitably substituted pyrroles and aldehydes. However, reactions of this type generally proceed in low yield, and cannot be used to produce many types of substituted porphyrins.
Accordingly, there exists a need in the art for synthetic methods capable of producing a greater variety of porphyrins than presently available.
OBJECTS OF THE INVENTION
It is one object of the present invention to provide improved methods for synthesizing substituted porphyrins.
It is another object of the invention to provide novel substituted porphyrins.
It is yet another object to provide novel porphyrin-containing compounds.
It is a further object of the invention to provide polymers containing linked porphyrin units.
It is still another object to provide new applications for substituted porphyrins and porphyrin-containing compounds.
SUMMARY OF THE INVENTION
These and other objects are satisfied by the present invention, which provides porphyrins having formula (1), (2), or (3): ##STR1## wherein M and M' are metal atoms and R.sub.A1 -R.sub.A4 and R.sub.B1 -R.sub.B8 are, independently, H or chemical functional groups that can bear a negative charge prior to attachment to a porphyrin compound. In certain preferred embodiments, at least one of R.sub.A1 -R.sub.A4 has formula CH.dbd.CH.sub.2 or at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 has formula C(R.sub.C).dbd.C(R.sub.D) (R.sub.E), provided that at least one of R.sub.C, R.sub.D, and R.sub.E is not H, where R.sub.C, R.sub.D, and R.sub.E are, independently, H, F, Cl, Br, I, alkyl or heteroalkyl having from 1 to about 20 carbon atoms, aryl or heteroaryl having about 4 to about 20 carbon atoms, alkenyl or heteroalkenyl having from 1 to about 20 carbon atoms, alkynyl or heteroalkynyl having from 1 to about 20 carbon atoms, trialkylsilyl or porphyrinato; M is a transition metal, a lanthanide, actinide, rare earth or alkaline metal. R.sub.C, R.sub.D, and R.sub.E also can include peptides, nucleosides, and/or saccharides.
In other preferred embodiments, at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 has formula C.ident.C(R.sub.D). In further preferred embodiments, at least one of R.sub.A1 -R.sub.A4 is haloalkyl having from 1 to about 20 carbon atoms. In further preferred embodiments, at least one of R.sub.B1 -R.sub.B8 is haloalkyl having 2 to about 20 carbon atoms or at least five of R.sub.B1 -R.sub.B8 are haloalkyl having from 1 to about 20 carbon atoms or haloaryl having from about 4 to about 20 carbon atoms. In further preferred embodiments, at least one of R.sub.B1 -R.sub.B8 is haloaryl or haloheteroaryl having about 4 to about 20 carbon atoms. In still further preferred embodiments, at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 includes an amino acid, peptide, nucleoside, or saccharide.
The present invention also provides processes and intermediates for preparing substituted porphyrins. In certain embodiments, the processes comprise providing a porphyrin compound having formula (1), (2), or (3) wherein at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 is a halogen and contacting the porphyrin compound with a complex having formula Y(L).sub.2 wherein Y is a metal and L is a ligand. This produces a first reaction product, which is contacted with an organometallic compound having general formula T(R.sub.L).sub.z (R.sub.O), T(R.sub.L).sub.z (R.sub.O).sub.y (X.sub.B).sub.w, T(R.sub.O) (X.sub.B) or T(R.sub.O).sub.y where T is a metal; X.sub.B is a halogen; R.sub.L is cyclopentadienyl or aryl having about 6 to about 20 carbon atoms; R.sub.O is alkyl having 1 to about 10 carbon atoms, alkenyl or alkynyl having 2 to about 10 carbon atoms, aryl having about 6 to about 20 carbon atoms; z and w are greater than or equal to 0; and y is at least 1. This contacting produces a second reaction product which, through reductive elimination, yields a third reaction product that contains a porphyrin substituted with R.sub.O.
In further embodiments, the processes comprise providing a porphyrin compound having formula (1), (2), or (3) wherein at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 is a halogen and contacting the porphyrin compound with an activated metal Z. This produces a ring-metalated porphyrin wherein metal Z has inserted into the porphyrin/halogen covalent bond. Alternatively, ring metalation of the halogenated porphyrin can be carried out with a catalytic amount of Y(L).sub.2 and an alkyltin reagent having formula (R).sub.3 Sn-Sn(R).sub.3, where R is alkyl having 1 to about 10 carbon atoms, to yield trialkyltin-substituted porphyrin. Either metalated porphyrin can be contacted with a compound having formula R.sub.P -R.sub.Z, where R.sub.P is cyclopentadienyl or aryl having about 6 to about 20 carbon atoms, alkyl having 1 to about 10 carbon atoms, alkenyl having 2 to about 10 carbon atoms, or porphyrinato and R.sub.Z is a leaving group such as a halogen, a tosylate, or a triflate. Such contacting should be performed in the presence of a catalyst having formula Y(L).sub.2, as defined above. This produces a porphyrin substituted with R.sub.P. Alternatively, the first reaction product can be contacted with an organic or organometallic quenching reagent.
In another aspect, the invention provides polymers comprising linked porphyrin units. In certain embodiments, porphyrin units having formula (1), (2), or (3) share covalent bonds. In other embodiments, at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 function as linking groups. In these embodiments, at least a portion of a linking group can have formula [C(R.sub.C).dbd.C(R.sub.D) (R.sub.E)].sub.x, [C.ident.C(R.sub.D)].sub.x, [CH.sub.2 (R.sub.C)--CH(R.sub.D)(R.sub.E)].sub.x or [CH.dbd.CH(R.sub.D)].sub.x where x is at least 1. The remaining of R.sub.A1 -R.sub.A4 and R.sub.B1 -R.sub.B8 can be H, halogen, alkyl or heteroalkyl having 1 to about 20 carbon atoms or aryl or heteroaryl having 4 to about 20 carbon atoms, C(RC).dbd.C(R.sub.D) (R.sub.E), C.ident.C(R.sub.D), or a chemical functional group that includes a peptide, nucleoside, and/or saccharide. In other preferred embodiments, the linking group is cycloalkyl or aryl having about 6 to about 22 carbon atoms.
The invention also provides processes for preparing porphyrin-containing polymers. In certain embodiments, the processes comprise providing at least two compounds that, independently, have formula (1), (2), or (3) wherein at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 in each of the compounds contains an olefinic carbon-carbon double bond or a chemical functional group reactive therewith. In other embodiments, at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 in each of the compounds contains a carbon-carbon triple bond or a chemical functional group reactive therewith. The compounds are then contacted for a time and under reaction conditions effective to form covalent bonds through the carbon-carbon double and/or triple bonds.
The porphyrins and porphyrin-containing polymers of the invention can be used, for example, as dyes, catalysts, contrast agents, antitumor agents, antiviral agents, and in chemical sensors and electrooptical devices.

BRIEF DESCRIPTION OF THE FIGURES
The numerous objects and advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures, in which:
FIG. 1 shows a linear polymer of the invention wherein R.sub.F1 is a covalent bond or a divalent functional group.
FIG. 2 shows a linear polymer of the invention having diacetylenic linking groups.
FIG. 3 shows a linear polymer of the invention having monoacetylenic and phenoxy linking groups, wherein R' is alkyl having from 1 to about 20 carbon atoms.
FIG. 4 shows a cross-linked polymer of the invention, wherein n, m, v, x, and y are at least 1.

DETAILED DESCRIPTION OF THE INVENTION
It has been found in accordance with the present invention that a wide variety of novel porphyrins can be prepared through metal-mediated cross coupling of a halogenated porphyrin core and a suitable organometallic moiety. In general, the resulting porphyrins have formula (1), (2), or (3): ##STR2## wherein M and M' are metal atoms and R.sub.A1 -R.sub.A4 and R.sub.B1 -R.sub.B8 are, independently, H or a variety of chemical functional groups that can bear a negative charge prior to attachment to a porphyrin compound. M preferably is a lanthanide or actinide or a metal such as Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, La, Hf, Ta, W, Re, Os, Ir, Pt. Cd, Hg, Li or Au. More preferably, M is a metal having a full valence shell, even more preferably Zn or Mg. M' can be a metal such as Li, Na, K, Rb, or Cs, preferably Li.
R.sub.A1 -R.sub.A4 and R.sub.B1 -R.sub.B8 can be virtually any chemical functional group or covalent assemblage of functional groups which, prior to attachment to a porphyrin compound, can bear a negative charge. In certain embodiments wherein R.sub.A1 -R.sub.A4 and R.sub.B1 -R.sub.B8 are appended to a porphyrin compound using the methods of the invention, these groups should be capable of bearing a carbon-centered negative charge (i.e., exist as a carbocentric anion in solution or otherwise). Preferably, R.sub.A1 -R.sub.A4 and R.sub.B1 -R.sub.B8 are primary or secondary alkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, aryl or heteroaryl. R.sub.A1 -R.sub.A4 and R.sub.B1 -R.sub.B8 should contain functionality that can withstand the reaction conditions associated with metal-mediated cross coupling. Those skilled in the art will recognize that chemical protecting groups can be attached to any sensitive functionality found within R.sub.A1 -R.sub.A4 and R.sub.B1 -R.sub.B8 and then removed after the coupling reactions have been completed.
Compounds having formulas (1)-(3) preferably bear 1, 2, 4, 8, or 12 substituents (i.e., 1, 2, 4, 8, or 12 of R.sub.A1 -R.sub.A4 and R.sub.B1 -R.sub.B8 are not H). More preferably, these compounds bear 2 or 4 substituents that contain alkenyl or alkynyl functionality.
In certain embodiments, at least one of R.sub.A1 -R.sub.A4 has formula CH.dbd.CH.sub.2. In other embodiments, at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 has formula C(R.sub.C).dbd.C(R.sub.D) (R.sub.E), provided that at least one of R.sub.C, R.sub.D, and R.sub.E is not H, or at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 has formula C.ident.C(R.sub.D). In further preferred embodiments, at least one of R.sub.A1 -R.sub.A4 is haloalkyl having from 1 to about 20 carbon atoms. In further preferred embodiments, at least one of R.sub.B1 -R.sub.B8 is haloalkyl having 2 to about 20 carbon atoms or at least five of R.sub.B1 -R.sub.B8 are haloalkyl having from 1 to about 20 carbon atoms. In further preferred embodiments, at least one of R.sub.B1 -R.sub.B8 is haloaryl or haloheteroaryl having about 4 to about 20 carbon atoms. Preferred halogenated moieties are fully halogenated (e.g., CF.sub.3). In still further embodiments, at least one of R.sub.A1 -R.sub.A4 or R.sub.B1 -R.sub.B8 is a single amino acid or a terminal amino acid of a polypeptide.
R.sub.C, R.sub.D, and R.sub.E can be any of a wide variety of chemical functional groups. Preferably, R.sub.C, R.sub.D, and R.sub.E are, independently, H, F, Cl, Br, I, alkyl or heteroalkyl having from 1 to about 20 carbon atoms, aryl or heteroaryl having about 4 to about 20 carbon atoms, alkenyl or heteroalkenyl having from 2 to about 20 carbon atoms, alkynyl or heteroalkynyl having from 2 to about 20 carbon atoms, trialkylsilyl, or porphyrinato. The terms heteroalklyl and heteroaryl are intended to denote moieties wherein a heteroatoms is inserted into the carbon backbone of an alkyl or aryl structure (e.g., ether, thioether, and pyridinyl groups). Representative heteroatoms include N, O, S, Se, and Te. The terms alkyl, aryl, alkenyl, and alkynyl are intended to include moieties substituted with, for example, halogens or nitro, acid, alkyl, or ester groups. Preferred alkyl and aryl groups have from 1 to about 10 carbon atoms and about 6 to about 14 carbon atoms, respectively. Preferred alkenyl and alkynyl groups have from 2 to about 10 carbon atoms. R.sub.C, R.sub.D, and R.sub.E preferably are alkyl, aryl, or trialkylsilyl.
R.sub.C, R.sub.D, and/or R.sub.E also can be chemical functional groups that include at least one peptide, nucleoside, and/or saccharide. For example, R.sub.C, R.sub.D, and R.sub.E can include a polymethylene chain connecting a DNA- or RNA-cleaving compound having formula (1), (2), or, in the absence of water, (3) with an oligonucleotide. (see, e.g., Stein, et al., Cancer Research 1988, 48, 2659). As will be recognized, peptides are compounds comprising two or more amino acids covalently bound through an amide linkage (e.g., glycylalanine), nucleosides are glycosides comprising covalently bound pentoses and heterocyclic bases (e.g., cytidine), and saccharides are hemiacetal forms of polyhydroxy aldehydes and ketones (e.g., sucrose). Each of these terms is intended to include both naturally occurring and non-naturally occurring moieties.
In preferred embodiments, each of R.sub.A1 -R.sub.A4 is alkyl or aryl and either R.sub.B5, R.sub.B5 and R.sub.B1, or R.sub.B5 and R.sub.B2 have formula C.ident.C(R.sub.D). In other preferred embodiments, each of R.sub.A1 -R.sub.A4 is alkyl or aryl and each of R.sub.B1 -R.sub.B8 have formula C.ident.C(R.sub.D). In still other preferred embodiments, R.sub.A1 has formula C.ident.C(R.sub.D), each of R.sub.A2 -R.sub.A4 are alkyl or aryl, at least one of R.sub.B1 -R.sub.B8 is H, alkyl or aryl, and R.sub.D is H, F, Cl, Br, I, alkyl, aryl, alkenyl, alkynyl, trialkylsilyl, or porphyrinato. In other preferred embodiments, R.sub.A1 and R.sub.A3 have formula C.ident.C(R.sub.D), R.sub.A2 and R.sub.A4 are alkyl, aryl or a halogen, at least one of R.sub.B1 -R.sub.B8 is H, alkyl, aryl or a halogen, and R.sub.D is H, F, Cl, Br, I, alkyl, aryl, alkenyl, alkynyl, trialkylsilyl, or porphyrinato; more preferably R.sub.D is 3,4,5-trialkyl-substituted phenyl or 3,4,5-trialkyloxy-substituted phenyl with the alkyl and alkoxy substituents having about 7 to about 20 carbon atoms. In still other preferred embodiments, R.sub.A1 -R.sub.A4 have formula C.ident.C(R.sub.D), at least one of R.sub.B1 -R.sub.B8 is H, alkyl, aryl or a halogen, and R.sub.D is H, F, Cl, Br, I, alkyl, aryl, alkenyl, alkynyl, trialkylsilyl, or porphyrinato, more preferably R.sub.D is H, 3,4,5-trialkyl-substituted phenyl, or 3,4,5-trialkoxy-substituted phenyl with the alkyl and alkoxy substituents having about 7 to about 20 carbon atoms.
In certain embodiments, the porphyrins of the invention are prepared by metal-mediated cross coupling of a halogenated, preferably brominated, chlorinated, or iodinated, porphyrin with an organometallic moiety. In other embodiments, the porphyrins of the invention are prepared by metal-mediated cross coupling of a metalated porphyrin with an organic moiety bearing a suitable leaving group. As will be recognized, the latter methods provide a means for attaching chiral substituents to a porphyrin core. Both metalated porphyrins (e.g., formulas (2) and (3)) and non-metalated porphyrins (e.g., formula (1)) can be used in the processes of the invention; the cross-coupling products can be metalated and de-metalated, as desired. The principles and techniques relating to metal-mediated cross coupling are well known to those skilled in the art to consist of three general steps: (1) oxidative addition, (2) transmetalation, and (3) reductive elimination. (See, e.g., Collman, et al., Principles and Applications of Organotransition Metal Chemistry, University Science Books, 1987, Mill Valley, Calif.; Kumada, Pure & Appl. Chem., 1980, 52, 669; Hayashi, et al., Tetrahedron Letters, 1979, 21, 1871.)
In accordance with certain embodiments of the invention, a halogenated porphyrin, P.sub.N -X.sub.A, is contacted with a catalyst having formula Y(L).sub.2 where Y is a metal such as, for example, Pd, Ni, Pt, Ru, or Cu and L is a ligand appropriate for that metal. When Y is Pd or Ni, L should be a phosphorous-, nitrogen-, arsenic-, or antimony-containing Lewis base such as an alkyl- or arylphosphine, an alkyl or arylarsenine, an alkyl- or arylstibene, a nitrogen-containing heterocycle such as pyridine, or a mixture thereof. The terms alkylphosphine, arylphosphine, alkylarsenine, arylarsenine, alkylstibene, and arylstibene are intended to describe moieties having at least one alkyl or aryl substituent such as, for example, monoalkylphosphines, trialkylphosphines, and dialkylmonoarylphosphines. Contacting the halogenated porphyrin with the catalyst complex is believed to produce a second compound having formula P.sub.N -Y(L).sub.2 X.sub.A, which is contacted with an organometallic compound having formula T(R.sub.L).sub.z (R.sub.O), T(R.sub.L).sub.z (R.sub.O).sub.t (X.sub.B).sub.w, T(R.sub.O) (X.sub.B) or T(R.sub.O).sub.t where T is a metal such as, for example, Li, Na, K, Rb, Cs, Hg, Sn, Al, B, Si, Zn, Zr, Cd, Cu, or Mg; X.sub.B is a halogen or an alkoxy group; R.sub.L is cyclopentadienyl or aryl having about 6 to about 20 carbon atoms; R.sub.O is alkyl, alkenyl or alkynyl having 1 to about 10 carbon atoms, aryl having about 6 to about 20 carbon atoms such as C(R.sub.C).dbd.C(R.sub.D) (R.sub.E), C.ident.C(R.sub.D), haloalkyl groups or haloaryl groups; z and w are greater than or equal to 0; and t is at least 1. T can be any metal that does not participate in an outer sphere electron transfer reaction with the porphyrin. Representative organometallic compounds are CuR.sub.O, Zn(R.sub.O).sub.2, ZnR.sub.O X.sub.B, (nBu).sub.3 SnR.sub.O, and Cp.sub.2 ZrR.sub.O X.sub.B (Cp=cyclopentadienyl). This contacting is believed to produce a third compound having formula P.sub.N -Y(L).sub.2 R.sub.O which, through reductive elimination, is transformed into substituted porphyrin P.sub.N -R.sub.O.
In other embodiments of the invention, metalated porphyrins are prepared by contacting halogenated porphyrins, P.sub.N -X.sub.A, with an activated metal Z. Alternatively, ring metalation of the halogenated porphyrin can be carried out with a catalytic amount of Y(L).sub.2 and an alkyltin reagent having formula (R).sub.3 Sn-Sn(R).sub.3, where R is alkyl having 1 to about 10 carbon atoms, to yield trialkyltin-substituted porphyrin. Z can be any metal that does not participate in an outer sphere electron transfer reaction with the porphyrin. Z preferably is Zn, Mg, Ca, Cd, Cu, Sn, Sr, Ba, or Zr. Preferably, the activated metal is prepared by contacting a metal reagent having formula Z(X.sub.C).sub.c where Z is a metal, X.sub.C is a halogen, and c is 1-4, with a reducing agent under conditions effective to reduce the metal reagent. In embodiments wherein the metal reagent is reduced in the presence of the porphyrin compound, the reducing agent should be effective to reduce the metal reagent but ineffective to reduce the porphyrin compound. Activated metals according to the invention can be prepared by, for example, the method of Ebert and Rieke, J. Org. Chem. 1984, 49, 5280 and J. Org. Chem. 1988, 53, 4482.
The metalated porphyrins can be contacted with compounds having formula R.sub.P -R.sub.Z, where R.sub.P is cyclopentadienyl or aryl having about 6 to about 20 carbon atoms, alkyl having 1 to about 10 carbon atoms, alkenyl having 2 to about 10 carbon atoms, or porphyrinato and R.sub.Z is a leaving group. Leaving groups include but are not limited halogen, alkyl-sulfonyl, substituted alkylsulfonyl, arylsulfonyl, substituted arylsulfonyl, hetercyclcosulfonyl or trichloroacetimidate. Preferred leaving groups include chloro, fluoro, bromo, iodo, p-(2,4-dinitroanilino)benzenesulfonyl, benzenesulfonyl, methylsulfonyl (mesylate), p-methylbenzenesulfonyl (tosylate), p-bromobenzenesulfonyl, trifluoromethylsulfonyl (triflate), trichloroacetimidate, acyloxy, 2,2,2-trifluoroethanesulfonyl, imidazolesulfonyl, and 2,4,6-trichlorophenyl. Contacting should be performed in the presence of a catalyst having formula Y(L).sub.2 where Y is a metal such as, for example, Pd, Ni, Pt, Ru, or Cu and L is a ligand appropriate for that metal. When Y is Pd or Ni, L should be a phosphorous-, nitrogen-, arsenic-, or antimony-containing Lewis base such as an alkyl- or arylphosphine, an alkyl or arylarsenine, an alkyl- or arylstibene, a nitrogen-containing heterocycle such as pyridine, or a mixture thereof.
Ring-metalated porphyrins alternatively can be contacted with organic or organometallic quenching reagents. Representative organic quenching reagents include those commonly used in the well known Grignard reaction, such as, for example, CO.sub.2, esters, aldehydes, ketones, acid chlorides, and amides. (see, e.g., J. March, Advanced organic Chemistry, John Wiley & Sons, 1985, New York) Organometallic quenching reagents include those disclosed by Azizian, et al., J. Organomet. Chem. 1981, 215, 49 and Barbero, et al., J. Chem. Soc. Chem. Commun. 1992, 351, such as, for example, trialkyl tin halides and trialkyl borates.
In general, the coupling reactions of the present invention proceed rapidly and in excellent yield, contrary to teaching in the prior art that reactions of this type should not work well with electron-rich systems such as porphyrins. It has been found that not all of the metals known for use in metal-mediated cross coupling reactions can be used to prepare substituted porphyrins. For example, coupling reactions wherein the metal T is lithium or magnesium have been found to proceed, if at all, in very low yield and with destruction of the porphyrin starting material. Also, coupling reactions wherein the metal Z is lithium, potassium, or sodium preferably are avoided.
The use of metal-mediated cross coupling in accordance with the invention can produce monomeric compounds suitable for incorporation into porphyrin-containing homopolymers or copolymers or into macromolecular or supramolecular species containing, for example, one or more peptides, nucleosides, or saccharides. Alternatively, metal-mediated cross-coupling can be used to directly prepare porphyrin-containing homopolymers or copolymers. The polymers according to the invention can contain as few as 2 porphyrin units, but more preferably contain at least 3 porphyrin units, more preferably at least 5 porphyrin units. In certain embodiments, polymers of the invention comprise a plurality of porphyrin units that, independently, have formula (1), (2), or (3) wherein at least one of R.sub.B1 -R.sub.B8 or R.sub.A1 -R.sub.A4 includes a linking group selected from [C(R.sub.C).dbd.C(R.sub.D)(R.sub.E)].sub.x, [C.ident.C(R.sub.D)].sub.x, [CH.sub.2 (R.sub.C)--CH(R.sub.D) (R.sub.E)].sub.x or [CH.dbd.CH(R.sub.D)].sub.x where x is at least 1. Preferably, the remaining of R.sub.A1 -R.sub.A4 are, independently, H, alkyl, alkenyl, alkynyl, or aryl and the remaining of R.sub.B1 -R.sub.B8 are, independently, H, alkyl, aryl, C(R.sub.C).dbd.C(R.sub.D)(R.sub.E), or C.ident.C(R.sub.D).
In other embodiments, polymers according to the invention comprise a plurality of porphyrin units that, independently, have formula (1), (2), or (3) wherein at least one of R.sub.B1 -R.sub.B8 or R.sub.A1 -R.sub.A4 is a cycloalkyl, cycloalkenyl, aryl or heteroaryl linking group having about 6 to about 22 carbon atoms.
Those skilled in the art will recognize the wide variety of polymers that can be prepared from the porphyrin-containing compounds of the invention. In certain embodiments, cofacial polymers are formed having, for example, formula (4). (see, e.g., Durand, et al., J. Am. Chem. Soc., 1983, 105, 2710). ##STR3##
In other embodiments, somewhat linear polymer chains are formed wherein a portion of the polymer has general formula (P.sub.N).sub.r where P.sub.N is a porphyrin unit and r is at least 2. In further embodiments, linear polymer chains have general formula:
[--(Q.sub.L).sub.l --(P.sub.N).sub.s --].sub.h
where Q.sub.L is a linking group, P.sub.N is a porphyrin unit, and h, l, and s are independently selected to be at least 1. For example, a portion of such polymers can have formula:
[--(P.sub.N1).sub.s' --(Q.sub.L1).sub.l' --(P.sub.N2).sub.s" --(Q.sub.L2).sub.l" ].sub.l
wherein P.sub.N1 and P.sub.N2 are independently selected porphyrin units, Q.sub.L1 and Q.sub.L2 are independently selected linking groups, and l', l", s', and s" are at least 1. These essentially linear polymer chains can be cross-linked such that a portion of the polymer has general formula:
[--(Q.sub.H).sub.h --(P.sub.N).sub.u --].sub.v
wherein Q.sub.H is a linking group, and h, u, and v are independently selected to be at least 1. A portion of these cross-linked polymers can have formula:
[--(P.sub.N3).sub.u' --(Q.sub.H1).sub.h' --(P.sub.N1).sub.u" --(Q.sub.H2).sub.h' --].sub.v
wherein P.sub.N3 is a porphyrin unit, Q.sub.H1 and Q.sub.H2 are independently selected linking groups, and h', h", u', and u" are at least 1. Thus, cross-linked polymers can have formulas: ##STR4## where r' is at least 1.
The polymers of the invention can be formed by contacting a substituted porphyrin with a second compound containing functionality that is reactive with the functionality contained within the porphyrin. Preferably, the porphyrin contains an olefinic carbon-carbon double bond, a carbon-carbon triple bond or some other reactive functionality. The contacting should be performed under conditions effective to form a covalent bond between the respective reactive functionalities. Preferably, porphyrin-containing polymers are formed by metal-mediated cross-coupling of, for example, dibrominated porphyrin units. Also, porphyrin-containing polymers can be synthesized using known terminal alkyne coupling chemistry. (see, e.g., Patai, et al., The Chemistry of Functional Groups, Supplement C, Part 1, pp. 529-534, Wiley, 1983; Cadiot, et al., Acetylenes, pp. 597-647, Marcel Dekker, 1964; and Eglinton, et al., Adv. Org. Chem., 1963, 4, 225) As will be recognized, the second compound noted above can be a substituted porphyrin of the invention or some other moiety such as an acrylate monomer. Thus, a wide variety of copolymeric structures can be synthesized with the porphyrins of the invention. Through careful substituent selection the porphyrins of the invention can be incorporated into virtually any polymeric matrix known in the art, including but not limited to polyacetylenes, polyacrylates, polyolefins, polyethers, polyurethanes, polycarbonates, polyanilines, polypyrroles, and polythiophenes. For example, fluorescent porphyrins can be incorporated into such polymers as end-capping groups.
The porphyrins and porphyrin-containing polymers of the invention can be used, for example, as dyes, catalysts, contrast agents, antitumor agents, antiviral agents, liquid crystals, in chemical sensors and in electrooptical and solar energy conversion devices. They also can be incorporated into supramolecular structures. The polymers and supramolecular structures, which anchor porphyrin units in a relatively stable geometry, should improve many of the known uses for porphyrins and even provide a number of new uses, such as in a solid phase system for sterilizing virus-containing solutions. Representative uses are disclosed by, for example, the following patents, which are incorporated herein by reference: U.S. Pat. No. 4,895,682 (Ellis, et al.); U.S. Pat. No. 4,986,256 (Cohen); U.S. Pat. No. 4,668,670 (Rideout, et al.); U.S. Pat. No. 3,897,255 (Erickson); U.S. Pat. No. 3,899,334 (Erickson); U.S. Pat. No. 3,687,863 (Wacher); U.S. Pat. No. 4,647,478 (Formanek, et al.); and U.S. Pat. No. 4,957,615 (Ushizawa, et al.). Further uses are disclosed are disclosed by, for example, U.K. Patent Application 2,225,963 (Casson, et al.); International Application WO 89/11277 (Dixon, et al.); International Application WO 91/09631 (Matthews, et al.); European Patent Application 85105490.8 (Weishaupt, et al.); European Patent Application 90202953.7 (Terrell, et al.); European Patent Application 89304234.1 (Matsushima, et al.); Lehn, Angew. Chem. Int. Ed. Engl., 1988, 27, 89; Wasielewski, Chem. Rev., 1992, 92, 435; Mansury, et al., J. Chem. Soc., Chem. Comm., 1985, 155; Groves, et al., J. Am. Chem. Soc., 1983, 105, 5791; and Giroud-Godquin, et al., Angew. Chem. Int. Ed. Engl., 1991, 30, 375. It is believed that the porphyrins of the invention can be substituted for the porphyrins disclosed in each of the foregoing publications.
Additional objects, advantages, and novel features of this invention will become apparent to those skilled in the art upon examination of the following examples thereof, which are not intended to be limiting.
EXAMPLE 1
5,15-Diphenylporphyrin
A flame-dried 1000 ml flask equipped with a magnetic stirring bar was charged with 2,2-dipyrrylmethane (458 mg, 3.1 mmol), benzaldehyde (315 .mu.l, 3.1 mmol), and 600 ml of freshly distilled (CaH.sub.2) methylene chloride. The solution was degassed with a stream of dry nitrogen for 10 minutes. Trifluoroacetic acid (150 .mu.l, 1.95 mmol) was added via syringe, the flask was shielded from light with aluminum foil, and the solution was stirred for two hours at room temperature. The reaction was quenched by the addition of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ, 900 mg, 3.96 mmol) and the reaction was stirred for an additional 30 minutes. The reaction mixture was neutralized with 3 ml of triethylamine and poured directly onto a silica gel column (20.times.2 cm) packed in hexane. The product was eluted in 700 ml of solvent. The solvent was evaporated, leaving purple crystals (518 mg., 1.12 mmol, 72.2%). This product was sufficiently pure for further reactions. Vis(CHCl.sub.3): 421 (5.55), 489 (3.63), 521 (4.20), 556 (4.04), 601 (3.71), 658 (3.73).
EXAMPLE 2
5,15-Dibromo-10,20-Diphenylporphyrin
5,15-Diphenylporphyrin (518 mg, 1.12 mmol) was dissolved in 250 ml of chloroform and cooled to 0.degree. C. Pyridine (0.5 ml) was added to act as an acid scavenger. N-Bromosuccinimide (400 mg, 2.2 mmol) was added directly to the flask and the mixture was followed by thin-layer chromatography (TLC; 50% CH.sub.2 Cl.sub.2 /hexanes eluant). After 10 minutes the reaction reached completion and was quenched with 20 ml of acetone. The solvents were evaporated and the product was washed with several portions of methanol and pumped dry to yield 587 mg (0.94 mmol, 85%) of reddish-purple solid. The compound was sufficiently pure to use in the next reaction. Vis(CHCl.sub.3): 421 (5.55), 489 (3.63), 521 (4.20), 556 (4.04), 601 (3.71), 658 (3.73).
EXAMPLE 3
5,15-Dibromo-10,20-Diphenylporphyrinato Zinc
5,15-Dibromo-10,20-diphenylporphyrin (587 mg, 0.94 mmol) was suspended in 30 ml DMF containing 500 mg ZnCl.sub.2. The mixture was heated at reflux for 2 hours and poured into distilled water. The precipitated purple solid was filtered through a fine fritted disk and washed with water, methanol, and acetone and dried in vacuo to yield 610 mg (0.89 mmol, 95%) of reddish purple solid. The compound was recrystallized from tetrahydrofuran (THF)/heptane to yield large purple crystals of the title compound (564 mg, 0.82 mmol, 88%). Vis(THF): 428 (5.50), 526 (3.53), 541 (3.66), 564 (4.17), 606 (3.95).
EXAMPLE 4
Meso-Substituted Porphyrins
General Procedure
In each of the following examples, 5,15-Dibromo-10,20-diphenylporphyrinato zinc (0.1 mmol), and Pd(PPh.sub.3).sub.4 (0.0025 mmol) were dissolved in 35 ml of distilled, degassed THF in a sealed storage tube with the 1 mmol of the indicated organometallic reagent and warmed at 60.degree. C. for 48 hours. The reaction was monitored by TLC on withdrawn aliquots. The mixture was quenched with water, extracted with chloroform, dried over CaCl.sub.2, evaporated and purified by column chromatography.
A. 5,15-Diphenyl-10,20-dimethylporphyrinato zinc
The organometallic reagent was methyl zinc chloride prepared from methyl lithium and anhydrous zinc chloride in THF.
The crude solid was dissolved in THF/heptane, poured onto 10 g silica gel and evaporated to dryness. This silica gel was loaded onto a column packed in 50% CH.sub.2 Cl.sub.2 /hexane. A single band was eluted (50% CH.sub.2 Cl.sub.2 /hexane) to yield pure 5,15-diphenyl-10,20-dimethylporphyrinato zinc (48 mg, 88%). An analytical sample was recrystallized from THF/heptane by slow evaporation under N.sub.2. .sup.1 H NMR (500 MHz, 3:1 CDCl.sub.3, D.sub.8 -THF) .delta. 9.34 (d, 4H, J=4.6); 8.71 (d, 4H, J=4.6); 8.02 (dd, 4H, J.sub.1 =7.5, J.sub.2 =1.4); 7.57 (m, 6H); 4.51 (s, 6H). .sup.13 C NMR (125 MHz, 3:1 CDCl.sub.3, D.sub.8 -THF) .delta. 150.07(0), 148.88(0), 143.34(0), 134.18(1), 131.42(1), 128.09(1), 126.73(1), 125.88(1), 119.29(0), 113.74(0), 20.81(3). Vis (THF) 424 (5.58), 522 (3.40), 559 (4.12); 605 (3.88).
B. 5,15-Diphenyl-10,20-divinylporphyrinato zinc
The organometallic reagent was tri-n-butylvinyl tin.
The crude product was absorbed on silica and loaded onto a column packed in hexane. Elution was carried out with CH.sub.2 Cl.sub.2 (0-50%)/hexane. A small quantity of purple material led the main fraction. The main band was evaporated to yield pure 5,15-diphenyl-10,20-divinylporphyrinato zinc (53 mg, 91%). An analytical sample was recrystallized from chloroform. .sup.1 H NMR (500 MHz, CDCl.sub.3) .delta. 9.52 (d, 4H, J=4.7); 9.24(dd, 2H, J.sub.1 =17.3, J.sub.2 =9.1); 8.92 (d, 4H, J=4.7); 8.19 (dd, 4H, J.sub.1 =6.8, J.sub.2 =2.0); 7.75 (m, 6H); 6.48 (dd, 2H, J.sub.1 =11.0, J.sub.2 =1.9); 6.05 (dd, 2H, J.sub.1 =17.3, J.sub.2 =2.0). .sup.13 C NMR (125 MHz, CDCl.sub.3) .delta. 163.40(1), 149.90(0), 149.21(0), 142.83(0), 137.97(0), 134.40(1), 132.10(1), 130.39(1), 127.50(1), 126.73(2), 126.57(1), 121.05(0).
C. 5,15-Bis (2,5-dimethoxyphenyl) -10,20-diphenylporphyrinato zinc
The organometallic reagent was 2,5-dimethoxyphenyl lithium, prepared from 1,4-dimethoxybenzene and t-butyl lithium in ether at -78.degree. C. The organolithium reagent was added to a solution of ZnCl.sub.2 in THF to yield the organozinc chloride reagent. This reagent was used immediately.
At the completion of the reaction two highly fluorescent spots were visible by TLC. The crude product was chromatographed on silica using CHCl.sub.3 as eluant. The first band off the column proved to be the C.sub.2h isomer of 5,15-bis(2,5-dimethoxyphenyl)-10,20-diphenylporphyrinato zinc. This band was evaporated leaving 33 mg (42%) of pure product. An analytical sample was recrystallized from chloroform. .sup.1 H NMR (500 MHz, CDCl.sub.3) .delta. 8.91 (s, 8H); 8.22 (d, 4H, J=6.5); 7.75 (m, 6H); 7.59 (d, 2H, J=2.2); 7.26 (broad s, 4H); 3.86 (s, 6H); 3.54 (s, 6H). .sup.13 C NMR (125 MHz, CDCl.sub.3) .delta. 154.10(0), 152.30(0), 150.13(0), 143.00(0), 134.10(1), 132.62(0), 132.00(1), 131.44(1), 127.35(1), 126.44(1), 121.34(1), 120.69(0), 116.59(0), 114.76(1), 112.31(1), 56.70(3), 55.95(3). Vis - 424 (5.64), 551 (4.34), 584 (3.43).
The C.sub.2v isomer followed the C.sub.2h isomer off the column. The solvent was evaporated leaving 30 mg (32%) of pure 5,15-bis(2,5-dimethoxyphenyl)-10,20-diphenylporphyrinato zinc. This compound is much more soluble in chloroform than the C.sub.2h isomer. The assignment of stereochemistry was made from the NMR data. .sup.1 H NMR (500 MHz, CDCl.sub.3) .delta. 8.90 (s, 8H); 8.21 (d, 2H, J=7.9); 8.19 (d, 2H, J=6.5);7.73 (m, 6H); 7.58 (s, 2H); 7.24 (broad s, 4H); 3.84(s, 6H); 3.53 (s, 6H). .sup.13 C NMR (125 MHz CDCl.sub.3) .delta. 154.14(0); 152.31(0), 150.15(0), 142.94(0), 134.40(1), 132.66(0), 132.02(1), 131.48(1), 127.37(1), 126.46(1), 126.44(1), 121.30(1), 120.72(0), 116.69(0), 114.73(1), 112.28(1), 56.75(3), 55.92(3).
D. 5,15-Bis[(4-methyl)-4'methyl-2,2'-dipyridyl)]-10,20-diphenylporphyrinato zinc
The organometallic reagent was tri-n-butyl[(4-methyl) -4'methyl-2,2'-dipyridyl)] tin, prepared by lithiating 4,4'-dimethyl-2,2'-dipyridyl with one equivalent of lithium diisopropylamide in THF at -78.degree. C. and warming the reaction mixture to room temperature. The organolithium reagent was treated with 1.1 equivalent of tributyltin chloride. The resulting organotin reagent was used without further purification.
Chromatography of the crude reaction mixture was carried out on silica with a mixture of CH.sub.2 Cl.sub.2, isopropanol, and triethylamine. The porphyrin was eluted in one broad band. The product obtained from this procedure (68% yield) was contaminated with a small amount (0.2 eq per eq of porphyrin) of triphenylphosphine. .sup.1 H NMR (500 MHz, CDCl.sub.3) .delta. 9.37 (d, 4H, J=4.7); 8.87 (d, 4H, J=4.7); 8.52 (s, 2H); 8.29 (d, 2H, J=5.1); 8.20 (d, 2H, J=5.2); 8.10 (m, 6H); 7.71 (m, 6H); 7.01 (d, 2H, J=5.0); 6.88 (d, 2H, J=4.2); 6.46 (s, 4H); 2.32 (s, 6H).
E. 5,15-Bis(trimethylsilylethynyl)-10,20-diphenylporphyrinato zinc
The organometallic reagent was trimethylsilyl ethynyl zinc chloride prepared from trimethylsilylethynyl lithium and anhydrous zinc chloride in THF.
After 48 hours the reaction was bright green. The crude solid was absorbed on silica gel, loaded onto a column packed in hexane, and chromatographed with 20%-30% CH.sub.2 Cl.sub.2 /hexane. Clean separation of the product from the small quantities of deprotected products were obtained by this method. The solvents were evaporated and the purple solid was washed twice with hexane and dried in vacuo. .sup.1 H NMR (500 MHz, CDCl.sub.3) .delta. 9.68 (d, 4H, J=4.6); 8.89 (d, 4H, J=4.6); 8.15 (dd, 4H, J.sub.1 =7.9, J.sub.2 =1.7); 7.75 (m, 6H); 0.58 (s, 18H). .sup.13 C NMR (125 MHz, CDCl.sub.3) .delta. 152.22, 150.26, 142.10, 134.39, 132.77, 131.29, 127.69, 126,67, 115.08, 107.34, 102.00, 0.32.
EXAMPLE 5
Pyrrole-Substituted Porphyrins
General Procedure
2-Bromo-5,10,15,20-tetraphenylporphyrinato zinc (0.1 mmol) and palladium 1,1'-bis(diphenylphosphino)ferrocene) dichloride (Pd(dppf)Cl.sub.2, 7 mg) were combined with 1.0 mmol of the organometallic reagent indicated below in 35 ml dry, degassed THF. The solution was allowed to stand for 12 hours, the solvent evaporated, and the compound purified by flash chromatography.
A. 2-Vinyl-5,10,15,20-tetraphenyl porphyrinato zinc
The organometallic reagent was tributylvinyl tin.
The crude reaction mixture was chromatographed on silica and eluted with 50% CH.sub.2 Cl.sub.2 /hexane. .sup.1 H NMR (250 MHz, CDCl.sub.3) .delta. 8.97 (s, 1H); 8.90 (m, 4H); 8.87 (d, 1H, J=4.7); 8.79 (d, 1H, J=4.7); 8.20 (m, 6H); 8.06 (d, 2H, J=6.6); 7.74 (m, 12H); 6.39 (dd, 1H, J.sub.1 =17.0, J.sub.2 =9.1); 5.83 (dd, 1H, J.sub.1 =17.1, J.sub.2 =2.0); 5.01 (dd, 1H, J.sub.1 =10.7, J.sub.2 =2.0). Vis (CHCl.sub.3) 426 (5.53), 517 (3.68); 555 (4.22), 595 (3.68).
B. 2-(2,5-dimethoxyphenyl)-5,10,15,20-tetraphenyl porphyrinato zinc
The organometallic reagent was 2,5-dimethoxyphenyl zinc chloride, prepared from the corresponding lithium reagent and anhydrous zinc chloride in THF/diethyl ether.
Flash chromatograph of the crude reaction mixture was carried out with chloroform. The title compound was isolated in 78% yield. .sup.1 H NMR (500 MHz, CDCl.sub.3) .delta.=8.94 (d, 1H, J=4.7); 8.93 (s,2H); 8.92 (d, 1H, J=4.8); 8.85 (s, 1H); 8.84 (d, 1H, J=4.7); 8.70 (d, 1H, J=4.7); 8.23 (m, 6H); 7.98 (d, 1H, J=7.0); 7.70 (m, 10H); 7.25 (quintet, 2H, J=7.4); 7.15 (t, 1H, J=7.0; 6.92 (d, 2H, J=3.1); 6.54 (dd, 1H, J.sub.1 =9.0, J.sub.2 =3.2); 6.40 (d, 1H, J=9.1); 3.68 (s, 3H); 3.42 (s, 3H). .sup.13 C NMR (125 MHz, CDCl.sub.3) .delta.=152.59(0), 151.33(0), 150.46(0), 150.31(0), 150.27(0), 150.15(0), 150.12(0), 150.03(0), 148.30(0), 147.16(0), 143.32(0), 142.97(0), 142.86, 140.71(0), 135.63(1), 135.20(1), 134.45(1), 134.13(1), 132.52(1), 132.02(1), 131.91(1), 131.82(1), 131.32(1), 129.27(0), 127.44(1), 127.38(1), 127.18(1), 126.53(1), 126.50(1), 124.91(1), 124.70(1), 122.36(0), 121.30(0), 120.91(0), 120.54(0), 118.15(1), 113.03(1), 110.35(1), 55.98(3), 54.87(3). Vis (CHCl.sub.3) 421.40 (5.60), 513.2 (3.45), 549.75 (4.28), 587.15 (3.45).
C. 2-(Trimethylsilyl ethynyl)-5,10,15,20-tetraphenyl porphyrinato zinc
The organometallic reagent, trimethylsilylacetylide zinc chloride, was prepared from the corresponding lithium reagent and anhydrous zinc chloride in THF.
The crude reaction mixture was chromatographed on silica and eluted with 50% CH.sub.2 Cl.sub.2 /hexane. .sup.1 H NMR (250 MHz, CDCl.sub.3) .delta. 9.25 (s, 1H); 8.89 (m, 4H); 8.85 (d, 1H, J=4.9); 8.76 (d, 1H, J=4.9); 8.16 (m. 6H); 8.09 (d, 2H, J=7.1); 7.67 (m, 12H); 0.21 (s, 9H). Vis (CHCl.sub.3) 431 (5.43), 523 (shoulder); 559 (4.18), 598 (3.67).
D. 2-n-butyl-5,10,15,20-tetraphenyl porphyrinato zinc
Butylzinc chloride was prepared from n-butyllithium and anhydrous zinc chloride in THF.
The crude reaction mixture was chromatographed on silica and eluted with 50% CH.sub.2 Cl.sub.2 /hexane. .sup.1 H NMR (250 MHz, CDCl.sub.3) .delta. 8.97 (m, 4H); 8.91 (d, 1H, J=4.7); 8.77 (d, 1H, J=4.7); 8.74 (s, 1H); 8.22 (m, 6H); 8.13 (d, 2H, J=7.3); 7.77 (m, 12H); 2.81 (t, 2H, J=7.7); 1.83 (quint, 2H, J=7.8); 1.30 (quint, 2H, J=7.6); 0.91 (t, 3H, J=8.2).
EXAMPLE 6
Vinylic-Bridged Porphyrins and their Polymers
A. cis-Bis-1,2-[5-(10,15,20-triphenylporphyrinato) zinc] ethene
5-Bromo-10,15,20-triphenylporphyrinato zinc (0.2 mmol) and Pd(PPh.sub.3).sub.4 (0.02 mmole) are dissolved in 25 ml dry, degassed THF. A solution of cis-bis(tri-n-butyltin)ethene (0.2 mmol) in 5 ml THF is added and the solution heated at reflux for 2 days. The reaction is quenched with water, extracted with methylene chloride, dried over calcium chloride, and the solvents are evaporated. The crude solid is chromatographed on silica using methylene chloride/hexane eluant to isolate a dimer having formula (3), wherein R.sub.A1, R.sub.A3, and R.sub.A4 are phenyl and M is Zn.
B. cis-Bis-1,2-{5-[10,15,20-tris(pentafluorophenyl)]-2,3,7,8,12,13,17,18-octakis-(trifluoromethyl)porphyrinato zinc}-1,2-difluoroethene
5-Bromo-10,15,20-tris (pentafluorophenyl) porphyrinato zinc (0.2 mmol) and Pd(PPh.sub.3).sub.4 (0.02 mmol) are dissolved in 25 ml dry THF. A solution of cis-bis(tri-n-butyltin)-1,2-difluoroethene (0.2 mmol) in 5 ml THF is added and the solution heated at reflux for 2 days. The reaction is quenched with water, extracted with methylene chloride, dried over calcium chloride, and the solvents evaporated. The crude solid is chromatographed on silica using methylene chloride/hexanes eluent to isolate cis-bis-1,2-{5-[10,15,20-tris(pentafluorophenyl)porphyrinatozinc}-1,2-difluoroethene. This material is dissolved in chloroform and reacted with a large excess of N-bromosuccinimide as in Example 2 to perbrominate positions R.sub.B1 -R.sub.B8 on both porphyrins. The resulting material filtered through a fine fritted disk and washed with water, methanol, and acetone, dried in vacuo, and then recrystallized from THF/heptane. cis-Bis-1,2-{5-[10,15,20-tris(pentafluoro-phenyl)-2,3,7,8,12,13,17,18-octabromoporphyrinato zinc is reacted with Pd(dppf) and a large excess of CuCF.sub.3 in the dark as in Example 4. After a reaction time of about 48 hours, the product is chromatographed on silica with CH.sub.2 Cl.sub.2 /CCl.sub.4 eluent to yield the title compound.
C. Cofacial-bis-[cis-ethenyl meso-bridged] porphyrin [CEBP] (Formula (5)) and Polymeric-bis-[cis-ethenyl meso-bridged] porphyrin [PABP] (Formula (6))
5,15-Dibromo-10,20-diphenylporphyrinato zinc (0.2 mmol) and Pd(PPh.sub.3).sub.4 (0.02 mmole) are dissolved in 25 ml dry, degassed THF. A solution of cis-bis(tri-n-butyltin)ethene (0.2 mmol) in 5 ml THF is added and the solution heated at reflux for 2 days. The reaction is quenched with water, extracted with methylene chloride, dried over calcium chloride, and the solvents are evaporated. The crude solid is chromatographed on silica using methylene chloride/hexane eluant to isolate the Cofacial-bis-[cis-ethenyl meso-bridged] zinc porphyrin complex of formula (5) and Polymeric-bis-[cis-ethenyl meso-bridged] porphyrin species of formula (6), wherein R.sub.A1 and R.sub.A3 are phenyl and M is Zn. ##STR5##
D. Fluorinated Cofacial-bis-[cis-ethenyl meso-bridged] porphyrin [FCEBP] and Fluorinated Polymeric-bis-[cis-ethenyl meso-bridged] porphyrin [FPEBP]
5,15-Dibromo-10,20-bis(pentafluorophenyl) porphyrinato zinc (0.2 mmol) and Pd(PPh.sub.3).sub.4 (0.02 mmol) are dissolved in 25 ml dry THF. A solution of cis-bis(tri-n-butyltin)-1,2-difluoroethene (0.02 mmol) in 5 ml THF is added and the solution heated at reflux for 2 days. The reaction is quenched with water, extracted with methylene chloride, dried over calcium chloride, and the solvents evaporated. The crude solid is chromatographed on silica using methylene chloride/hexanes eluent to isolate the Cofacial-bis-[cis-ethenyl meso-bridged] zinc porphyrin complex as well as the Polymeric-bis-[cis-ethenyl meso-bridged] porphyrin species. The cofacial and polymeric species are dissolved separately in chloroform. The cofacial porphyrin complex dissolved in chloroform and reacted with a large excess of N-bromosuccinimide as in Example 2 to perbrominate positions R.sub.B1 -R.sub.B8 on both porphyrins. The resulting material filtered through a fine fritted disk and washed with water, methanol, and acetone, dried in vacuo, and then recrystallized from THF/heptane to yield the title compound. The isolated material is reacted with Pd(dppf) and a large excess of CuCF.sub.3 in the dark in a manner as in Example 4. After a reaction time of about 48 hours, the product is chromatographed on silica with CH.sub.2 Cl.sub.2 /CCl.sub.4 eluent to yield a perfluorinated CEPB analogous to formula (5). Perfluorinated PEBP is synthesized in a similar manner, yielding a species analogous to formula (6) where highly fluorinated porphyrins are linked via fluorovinyl units.
E. Cofacial-bis-1,8-anthracenyl-meso-bridged] porphyrin [CBAP] (Formula (7)) and Polymeric-bis-[1,8-anthracenyl-meso-bridged] [PBAP] porphyrin (Formula (8))
5,15-(Dibromoporphyrinato)zinc (0.2 mmol) and Pd(PPh.sub.3).sub.4 (0.02 mmol) are dissolved in 25 ml dry, degassed THF. A solution of 1,8-anthracenyl-bis-(tributyl tin) (0.2 mmol) in 5 ml THF is added and the solution heated at reflux for 2 days. The reaction is quenched with water, extracted with methylene chloride, dried over calcium chloride, and the solvents are evaporated. The crude solid is chromatographed on silica using methylene chloride/hexane eluant to isolate the Cofacial-bis-[1,8-anthracenyl-meso-bridged] zinc porphyrin complex of formula (7) and the Polymeric-bis-[1,8-anthracenyl-meso-bridged] zinc porphyrin species of formula (8), where R.sub.A1 and R.sub.A3 are phenyl and M is Zn. ##STR6##
EXAMPLE 7
Acetylenic Porphyrin Polymers
A. Poly(5,15-bis(ethynyl)-10,20-diphenyl-porphyrinato zinc)
5,15-Bis(ethynyl)-10,20-diphenylporphyrinato zinc (0.2 mmol) in pyridine (20 ml) is slowly added to a solution of cupric acetate (0.4 mmol) in 20 ml 1:1 pyridine/methanol generally according to the procedure of Eglinton, et al., The Coupling of Acetylenic Compounds, p. 311 in Advances in Organic Chemistry, Raphael, et al., eds., 1963, Interscience Publishers.
B. Poly(5,15-bis (ethynylphenyl) -10,20-diphenyl-porphyrinato zinc)
5,15-Diethynyl-10,20-diphenylporphinato zinc (0.2 mmol) and 1,4-dibromobenzene are combined in a mixture of 30 ml toluene and 10 ml diisopropylamine. Cul (0.4 mmol) and Pd(Ph.sub.3).sub.4 (0.02 mmol) are added and the mixture is heated at 65.degree. C. for 3 days. The crude solid is washed with methanol and acetone and dried in vacuo.
Alternatively, the polymer is prepared from 1,4-diethynylbenzene and 5,15-dibromo-10,20-diphenylporphinato zinc via the identical procedure.
EXAMPLE 8
Doped Porphyrin Polymers
5,15-Bis(ethynyl)-10,20-diphenylporphyrinato zinc is polymerized according to the generally procedure provided by Skotheim, ed., Handbook of Conducting Polymers, Volume 1, pp. 405-437, Marcel Dekker, 1986 using a catalytic amount of MoCl.sub.5, Mo(CO).sub.6, WCl.sub.6, or W(CO).sub.6. The resultant polymer is then doped with an oxidant such as iodine or SbF.sub.5.
EXAMPLE 9
Metalation of Brominated Porphyrins
Finely divided zinc metal was prepared generally according to the method of Rieke (J. Org. Chem. 1984, 49, 5280 and J. Org. Chem. 1988, 53, 4482) from sodium naphthalide and zinc chloride (0.18 mmol each) in THF. A solution of [5-bromo-10,20-diphenylporphinato]zinc (100 mg, 0.17 mmol) dissolved in 40 mL THF was added by syringe to the zinc metal suspension, and the mixture was stirred at room temperature overnight; during this time all of the zinc metal dissolved. The ring-metalated porphyrin is suitable for palladium-catalyzed coupling with a variety of aryl and vinyl halides.
EXAMPLE 10
Palladium-Catalyzed Cross-Coupling with Ring-Metalated Porphyrins
5-[(10,20-Diphenylporphinato)zinc]zinc bromide(0.2 mmol) is prepared in 15 mL of THF as in Example 9 above and is placed in a dry 100 mL Schlenk tube. A solution of 2-iodothiophene (0.4 mmol) in 5 mL of THF is added via syringe. Pd(dppf) (3 mg) is prepared by stirring a suspension of Pd(dppf)Cl.sub.2 in THF over Mg turnings for 20 min. and is transferred into the reaction mixture by canula. The solution is stirred overnight, quenched with aqueous ammonium chloride, extracted with CH.sub.2 Cl.sub.2, and dried over CaCl.sub.2. The solvent is evaporated to dryness and chromatography is carried out with 1:1 CH.sub.2 Cl.sub.2 as eluant. The product, [5-(2-thiophenyl)-10,20-diphenylporphinato]zinc, elutes in one band and is isolated in 90% yield.
EXAMPLE 11
Polymerization with Ring-Metalated Porphyrin Derivatives
[5,15-Bis(zinc bromide)-10,20-diphenylporphinato]-zinc (0.2 mmol) is prepared in 15 mL of THF as in Example 9 and is placed in a dry 100 mL Schlenk tube. A solution of [5,15-dibromo-10,20-diphenylporphinato]zinc (0.2 mmol) in 15 mL of THF is added by syringe. Pd(dppf) (3 mg) is prepared by stirring a suspension of Pd(dppf)Cl.sub.2 in THF over Mg turnings for 20 min. and is transferred into the reaction mixture by canula. The mixture is heated at 60.degree. C. for 3 days, cooled to room temperature and filtered through a fine-fritted glass disk. The filtered polymer is washed with hexane followed by methanol and dried in vacuo.
EXAMPLE 12
Carbonylation of [5-Bromo-10,20-Diphenylporphinato]Zinc
5-[(10,20-Diphenylporphinato)zinc]magnesium bromide (0.2 mmol) is prepared in 15 mL of THF as in Example 9 and is placed in a dry 100 mL Schlenk tube. The vessel is cooled to 0.degree. C. and dry CO.sub.2 gas is bubbled through the solution. The solution is stirred for 1 h at room temperature, quenched with 0.1 M HCl, extracted with CH.sub.2 Cl.sub.2, and dried over CaCl.sub.2. The solvent is evaporated to dryness and chromatography is carried out with THF:CH.sub.2 Cl.sub.2 as eluant. Upon evaporation of the solvent [5-carboxy-10,20-diphenylporphinato]zinc is isolated in 85% yield.
EXAMPLE 13
Coupling on Unmetalated Porphyrin Derivatives
A. Using Organozinc Chloride Reagents
Trimethylsilylacetylene (3 mmol) was deprotonated with n-butyl lithium (3 mmol) at -78.degree. C. in THF and warmed slowly to room temperature. Excess ZnCl.sub.2 (650 mg) in 5 mL of THF was transferred into the solution via canula. Pd(dppf) (3 mg) was prepared by stirring a suspension of Pd(dppf)Cl.sub.2 in THF over Mg turnings for 20 min. and transferred into the solution by canula. The entire reaction mixture was transferred to a dry 100 mL Schlenk tube containing 340 mg of 5,15-dibromo-10,20-diphenylporphyrin. The solution was heated to 40.degree. C. and left sealed overnight. TLC of the reaction mixture after 18 h shows a mixture of fluorescent products. The mixture was quenched with aqueous ammonium chloride, extracted with CH.sub.2 Cl.sub.2, and dried over CaCl.sub.2. The solvent was evaporated to dryness and chromatography was carried out with 1:1 CH.sub.2 Cl.sub.2 :hexane as eluant. The majority of the material was collected in two bands which proved to be (5-(2-trimethylsilylethynyl)-10,20-diphenylporphinato]zinc and [5,15-bis (2-trimethylsilylethynyl) -10,20-diphenylporphinato]-zinc. The two products were isolated in 83% overall yield.
B. Using Organotrialkyltin Reagents
5,15-Dibromo-10,20-diphenylporphyrin is placed in a dry 100 mL Schlenk tube and dissolved in 30 mL of THF. A solution of vinyltributyltin (3 mmol) in 5 mL THF is added to the reaction mixture. Pd(dppf) (3 mg) is prepared by stirring a suspension of Pd(dppf)Cl.sub.2 in THF over Mg turnings for 20 min. and is transferred into the reaction mixture by canula. The solution is stirred overnight, quenched with aqueous ammonium chloride, extracted with CH.sub.2 Cl.sub.2, and dried over CaCl.sub.2. The solvent is evaporated to dryness and chromatography is carried out with 1:1 CH.sub.2 Cl.sub.2 :hexane as eluant. The product, 5,15-diphenyl-10,20-divinylprophyrin, elutes in one band and is isolated in 90% yield.
EXAMPLE 14
Coupling on Dilithialated Porphyrin Derivatives
A solution of N,N"-dilithio-5,15-dibromo-10,20-diphenylporphyrin (0.2 mmol) in 15 mL of THF is prepared generally according to the method of Arnold, J. Chem. Soc. Commun. 1990, 976. A solution of vinyltributyltin (2 mmol) in 5 mL THF is added to the reaction mixture. Pd(dppf) (3 mg) is prepared by stirring a suspension of Pd(dppf)Cl.sub.2 in THF over Mg turnings for 20 min. and is transferred into the reaction mixture by canula. The solution is stirred overnight, and quenched with a solution of anhydrous NiCl.sub.2 in THF. Aqueous ammonium chloride is added, the solution is extracted with CH.sub.2 Cl.sub.2, and dried over CaCl.sub.1. The solvent is evaporated to dryness and chromatography is carried out with 1:1 CH.sub.2 Cl.sub.2 :hexane as eluant. The product, [5,15-diphenyl-10,20-divinylporphinato]nickel, elutes in one band and is isolated in 90% yield.
Those skilled in the art will appreciate that numerous changes and modifications may be made to the preferred embodiments of the invention and that such changes and modifications may be made without departing from the spirit of the invention. For example, it is believed that the methods of the present invention can be practiced using porphyrin-related compounds such as chlorins, phorbins, bacteriochlorins, porphyrinogens, sapphyrins, texaphrins, and pthalocyanines in place of porphyrins. It is therefore intended that the appended claims cover all such equivalent variations as fall within the true spirit and scope of the invention.

Number	Name	Date
5438071	Clauss et al.	Aug 1995
5675001	Hoffman et al.	Oct 1997
5756723	Therien et al.	May 1998

	Number	Date	Country
Parent	600207	Feb 1996
Parent	064468	May 1993

Metal-mediated cross-coupling with ring-metalated porphyrins

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