Cyclopentadienyl, indenyl or fluorenyl substituted phosphine compounds and their use in catalytic reactions

Abstract

A phosphine compound represented by general formula (1) wherein R′ and R″ independently are selected from alkyl, cycloalkyl and 2-furyl radicals, or R′ and R″ are joined together to form with the phosphorous atom a carbon-phosphorous monocycle including at least 3 carbon atoms or a carbon-phosphorous bicycle; the alkyl radicals, cycloalkyl radicals, and carbon-phosphorous monocycle being unsubstituted or substituted by at least one radical selected from the group of alkyl, cycloalkyl, aryl, alkoxy, and aryloxy radicals; Cp s is a partially substituted or completely substituted cyclopentadien-1-yl group, including substitutions resulting in a fused ring system, and wherein a substitution at the 1-position of the cyclopentadien-1-yl group is mandatory when the cyclopentadien-1-yl group is not part of a fused ring system or is part of an indenyl group. These phosphines can be used as ligands in catalytic reactions.

1 . A phosphine compound represented by the general formula (1) 
     
       
         
         
             
             
         
       
     
     or a corresponding phosphonium salt represented by the general formula (1a) 
     
       
         
         
             
             
         
       
     
     wherein
 R′ and R″ independently are selected from alkyl, cycloalkyl and 2-furyl radicals, or R′ and R″ are joined together to form with the phosphorous atom a carbon-phosphorous monocycle comprising at least 3 carbon atoms or a carbon-phosphorous bicycle; the alkyl radicals, cycloalkyl radicals, and carbon-phosphorous monocycle being unsubstituted or substituted by at least one radical selected from the group of alkyl, cycloalkyl, aryl, alkoxy, and aryloxy radicals; 
 Cp s  is a partially substituted or completely substituted cyclopentadien-1-yl group, including substitutions resulting in a fused ring system, and wherein a substitution at the 1-position of the cyclopentadien-1-yl group is mandatory when the cyclopentadien-1-yl group is not part of a fused ring system or is part of an indenyl group; and 
 Y −  represents an anion; 
 excluding a phosphine compound represented by formula (A) 
 
     
       
         
         
             
             
         
       
     
     or formula (B) 
     
       
         
         
             
             
         
       
     
     and their corresponding phosphonium salts (Aa) and (Ba), wherein Me represents a methyl radical and tBu represents a t-butyl radical. 
   
   
       2 . The phosphine compound or its corresponding phosphonium salt according to  claim 1  wherein Cp s  is a partially substituted or completely substituted ind-2-en-1-yl or ind-2-en-2-yl group, preferably a partially substituted or completely substituted ind-2-en-1-yl group, including substitutions resulting in an enlarged fused ring system. 
   
   
       3 . The phosphine compound or its corresponding phosphonium salt according to  claim 2  wherein Cp s  is an unsubstituted, partially substituted or completely substituted fuoren-9-yl group, including substitutions resulting in an enlarged fused ring system. 
   
   
       4 . The phosphine compound according to  claim 1  represented by the general formula (2) 
   
   
       5 . 
     
       
         
         
             
             
         
       
     
     or its corresponding phosphonium salt represented by the general formula (2a) 
     
       
         
         
             
             
         
       
     
     wherein
 R is selected from the group consisting of aliphatic, heteroaliphatic, aromatic, alicyclic, heterocyclic radicals, heteroatom-containing radicals comprising an aromatic, alicyclic, or heterocyclic radical and an additional heteroatom linking the aromatic, alicyclic, or heterocyclic radical atom with the carbon atom of the cyclopentadienyl group, all the foregoing radicals being unsubstituted or substituted by further carbon and/or heteroatoms; and organosilyl radicals; and 
 R 1 , R 2 , R 3 , and R 4  independently are selected from the group consisting of H; aliphatic, heteroaliphatic, aromatic, alicyclic, heterocyclic radicals, heteroatom-containing radicals comprising an aromatic, alicyclic, or heterocyclic radical and an additional heteroatom linking the aromatic, alicyclic, or heterocyclic radical atom with the carbon atom of the cyclopentadienyl group, all the foregoing radicals being unsubstituted or substituted by further carbon and/or heteroatoms; halogens; and heteroatom-containing groups; or adjacent groups selected from R 1 , R 2 , R 3 , and R 4  together form a divalent radical thereby forming a fused ring system. 
 
   
   
       6 . The phosphine compound according to  claim 2  represented by the general formula (3) 
     
       
         
         
             
             
         
       
     
     or its corresponding phosphonium salt represented by the general formula (3a) 
     
       
         
         
             
             
         
       
     
     wherein
 R is selected from the group consisting of aliphatic, heteroaliphatic, aromatic, alicyclic, heterocyclic radicals, heteroatom-containing radicals comprising an aromatic, alicyclic, or heterocyclic radical and an additional heteroatom linking the aromatic, alicyclic, or heterocyclic radical atom with the carbon atom of the indenyl group, all the foregoing radicals being unsubstituted or substituted by further carbon and/or heteroatoms; and organosilyl radicals; and 
 R 5 , R 6 , R 7 , R 8 , R 9 , and R 10  independently are selected from the group consisting of H; aliphatic, heteroaliphatic, aromatic, alicyclic, heterocyclic radicals, heteroatom-containing radicals comprising an aromatic, alicyclic, or heterocyclic radical and an additional heteroatom linking the aromatic, alicyclic, or heterocyclic radical atom with the carbon atom of the indenyl group, all the foregoing radicals being unsubstituted or substituted by further carbon and/or heteroatoms; halogens; and heteroatom-containing groups; or adjacent groups selected from R 5 , R 6 , R 7 , R 8 , R 9 , and R 10  together form a divalent radical thereby forming a fused ring system. 
 
   
   
       7 . The phosphine compound according to  claim 3  represented by the general formula (4): 
     
       
         
         
             
             
         
       
     
     or its corresponding phosphonium salt represented by the general formula (4a): 
     
       
         
         
             
             
         
       
     
     wherein
 R is selected from the group consisting of hydrogen; aliphatic, heteroaliphatic, aromatic, alicyclic, heterocyclic radicals, heteroatom-containing radicals comprising an aromatic, alicyclic, or heterocyclic radical and an additional heteroatom linking the aromatic, alicyclic, or heterocyclic radical atom with the carbon atom of the fluorenyl group, all the foregoing radicals being unsubstituted or substituted by further carbon and/or heteroatoms; and organosilyl radicals; 
 R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , and R 18  independently are selected from the group consisting of H; aliphatic, heteroaliphatic, aromatic, alicyclic, heterocyclic radicals, heteroatom-containing radicals comprising an aromatic, alicyclic, or heterocyclic radical and an additional heteroatom linking the aromatic, alicyclic, or heterocyclic radical atom with the carbon atom of the fluorenyl group, all the foregoing radicals being unsubstituted or substituted by further carbon and/or heteroatoms; halogens; and heteroatom-containing groups; or adjacent groups selected from R 11 , R 12 , R 13 , R 14 , R 15 R 16 , R 17 , and R 18  together form a divalent radical thereby forming a fused ring system. 
 
   
   
       8 . The phosphine compound or its corresponding phosphonium salt according to  claim 4  wherein
 R is selected from the group consisting of alkyl, cycloalkyl, aryl, aralkyl, alkenyl, alkynyl, alkoxy, and alkylsilyl radicals that are unsubstituted or substituted by further carbon and/or heteroatoms; and   R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , and R 18  independently are selected from the group consisting of H, alkyl, cycloalkyl, aryl, and alkoxy radicals that are unsubstituted or substituted; halogens, and heteroatom-containing groups imparting water-solubility.   
   
   
       9 . The phosphine compound or its corresponding phosphonium salt according to  claim 7  wherein
 R is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-octadecyl, benzyl, and phenyl radicals that are unsubstituted or substituted, preferably unsubstituted;   and R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , and R 18  independently are selected from the group consisting of H, a methyl radical, a methoxy radical, and —SO 3 H.   
   
   
       10 . The phosphine compound or its corresponding phosphonium salt according to  claim 1  wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17  and R 18  are hydrogen. 
   
   
       11 . The phosphine compound or its corresponding phosphonium salt according to  claim 1  wherein R is an unbranched alkyl radical or a benzyl radical. 
   
   
       12 . The phosphine compound or its corresponding phosphonium salt according to  claim 10  wherein R is a methyl or ethyl radical. 
   
   
       13 . The phosphine compound or its corresponding phosphonium salt according to  claim 1  wherein R′ and R″ independently are selected from the group consisting of isopropyl, n-butyl, t-butyl, neopentyl, cyclohexyl, and adamantyl radicals, or R′ and R″ are joined together to form a [3.3.1] or [4.2.1]-phobyl radical with the phosphorous atom. 
   
   
       14 . The phosphine compound or its corresponding phosphonium salt according to  claim 12  wherein R′ and R″ independently are selected from the group consisting of isopropyl and cyclohexyl radicals. 
   
   
       15 . The phosphine compound or its corresponding phosphonium salt according to  claim 1  wherein R′ and R″ are the same radicals. 
   
   
       16 . The phosphine compound or its corresponding phosphonium salt according to  claim 6  which is selected from the group consisting of 
     (9-methylfluoren-9-yl)diisopropylphosphine (9-MeFluPiPr 2 ) (5), 
     
       
         
         
             
             
         
       
     
     (9-ethylfluoren-9-yl)diisopropylphosphine (9-EtFluPiPr 2 ) (6), 
     
       
         
         
             
             
         
       
     
     (9-benzylfluoren-9-yl)diisopropylphosphine (9-BnFluPiPr 2 ) (26), 
     
       
         
         
             
             
         
       
     
     (9-octadecylfluoren-9-yl)diisopropylphosphine (9-C 18 H 37 FluPiPr 2 ) (7), 
     
       
         
         
             
             
         
       
     
     (9-methylfluoren-9-yl)dicyclohexylphosphine (9-MeFluPCy 2 ) (8), 
     
       
         
         
             
             
         
       
     
     (9-ethylfluoren-9-yl)dicyclohexylphosphine (9-EtFluPCy 2 ) (9), 
     
       
         
         
             
             
         
       
     
     (9-benzylfluoren-9-yl)dicyclohexylphosphine (9-BnFluPCy 2 ) (10), 
     
       
         
         
             
             
         
       
     
     (9-octadecylfluoren-9-yl)dicyclohexylphosphine (9-C 18 H 37 FluPCy 2 ) (11), 
     
       
         
         
             
             
         
       
     
     (1-methyl-9-ethylfluoren-9-yl)dicyclohexylphosphine (9-Et-1-MeFluPCy 2 ) (12), 
     
       
         
         
             
             
         
       
     
     (9-ethyl-2-sulfofluoren-9-yl)dicyclohexylphosphine (2-SO 3 H-9-EtFluPCy 2 ) (13), 
     
       
         
         
             
             
         
       
       and their corresponding phosphonium salts 
       9-MeFluPiPr 2 .H+Y −  (5a), 
       9-EtFluPiPr 2 .H + Y −  (6a), 
       9-BnFluPiPr 2 .H + Y −  (26a), 
       9-C 18 H 37 FluPiPr 2 .H + Y −  (7a), 
       9-MeFluPCy 2 .H + Y −  (8a), 
       9-EtFluPCy 2 .H + Y −  (9a), 
       9-BnFluPCy 2 .H + Y −  (10a), 
       9-C 18 H 37 FluPCy 2 .H + Y −  (11a), 
       9-Et-1-MeFluPCy 2 .H + Y −  (12a), and 
       9-Et-2-SO 3 HFluPCy 2 .H + Y −  (13a), 
       wherein Flu represents a fluoren-9-yl radical, Me represents a methyl radical, Et represents an ethyl radical, Bn represents a benzyl radical, iPr represents an isopropyl radical, and Cy represents a cyclohexyl radical. 
     
   
   
       17 . The phosphonium salt according to  claim 1  wherein Y −  is BF 4   − . 
   
   
       18 . A coordination compound comprising
 (i) a phosphine compound phosphine compound represented by the general formula (1)   
     
       
         
         
             
             
         
       
     
     wherein
 R′ and R″ independently are selected from alkyl, cycloalkyl and 2-furyl radicals, or R′ and R″ are joined together to form with the phosphorous atom a carbon-phosphorous monocycle comprising at least 3 carbon atoms or a carbon-phosphorous bicycle; the alkyl radicals, cycloalkyl radicals, and carbon-phosphorous monocycle being unsubstituted or substituted by at least one radical selected from the group of alkyl, cycloalkyl, aryl, alkoxy, and aryloxy radicals; 
 Cp s  is a partially substituted or completely substituted cyclopentadien-1-yl group, including substitutions resulting in a fused ring system, and wherein a substitution at the 1-position of the cyclopentadien-1-yl group is mandatory when the cyclopentadien-1-yl group is not part of a fused ring system or is part of an indenyl group; and 
 (ii) a transition metal selected from groups 8, 9, 10, and 11 of the Periodic Table of the Elements. 
 
   
   
       19 . The coordination compound according to  claim 17  wherein the transition metal is selected from Pd, Ni, Pt, Rh, Ir, Ru, Co, Fe, Cu, and Au. 
   
   
       20 . The coordination compound according to  claim 18  wherein the transition metal is Pd or Ni, preferably Pd. 
   
   
       21 . The coordination compound according to  claim 17  wherein the phosphine compound is defined as above. 
   
   
       22 . A process for preparing an organic compound comprising carrying out a reaction to produce said organic compound in the process of a coordination compound according to  claim 17  as a catalyst or a part of a catalyst system. 
   
   
       23 . A composition comprising a phosphine compound represented by the general formula (1) 
     
       
         
         
             
             
         
       
     
     or a corresponding phosphonium salt represented by the general formula (1a) 
     
       
         
         
             
             
         
       
     
     wherein
 R′ and R″ independently are selected from alkyl, cycloalkyl and 2-furyl radicals, or R′ and R″ are joined together to form with the phosphorous atom a carbon-phosphorous monocycle comprising at least 3 carbon atoms or a carbon-phosphorous bicycle; the alkyl radicals, cycloalkyl radicals, and carbon-phosphorous monocycle being unsubstituted or substituted by at least one radical selected from the group of alkyl, cycloalkyl, aryl, alkoxy, and aryloxy radicals; 
 Cp s  is a partially substituted or completely substituted cyclopentadien-1-yl group, including substitutions resulting in a fused ring system, and wherein a substitution at the 1-position of the cyclopentadien-1-yl group is mandatory when the cyclopentadien-1-yl group is not part of a fused ring system or is part of an indenyl group; and 
 Y −  represents an anion; 
 in combination with a transition metal compound as a catalyst or a part of a catalyst system for the preparation of an organic compound wherein the transition metal is defined as in  claim 17 . 
 
   
   
       24 . The process according to  claim 22  wherein the phosphine compound and its corresponding phosphonium salt are defined as above. 
   
   
       25 . The process according to  claim 22  wherein preparation of the organic compound includes the formation of a C—C bond or C-heteroatom bond. 
   
   
       26 . The process according to  claim 24  wherein the transition metal is Pd. 
   
   
       27 . The process according to  claim 22  which includes the formation of a C—C bond, the organic compound being prepared by a reaction selected from the group consisting of:
 (a) Suzuki cross-coupling of organoboron compounds with aryl, heteroaryl or vinyl halides or pseudohalides;   (b) Stille cross-coupling of organotin compounds with carbon electrophiles comprising a halogen or pseudohalogen as leaving group;   (c) Hiyama cross-coupling of organosilanes with aryl, heteroaryl or vinyl halides or pseudohalides;   (d) Negishi cross-coupling of organozinc compounds with aryl, heteroaryl or vinyl halides or pseudohalides;   (e) Kumada cross-coupling of Grignard compounds with aryl, heteroaryl or vinyl halides or pseudohalides;   (f) Sonogashira cross-coupling of terminal alkynes with aryl, heteroaryl or vinyl halides or pseudohalides;   (g) α-arylation of enolates and other stabilized carbanions with aryl or heteroaryl halides or pseudohalides;   (h) cyanation of aryl or heteroaryl halides or pseudohalides;   (i) carbonylation of aryl or heteroaryl halides or pseudohalides; and   (j) Heck coupling of aryl, heteroaryl or vinyl halides or pseudohalides to olefins.   
   
   
       28 . The process according to  claim 24  wherein the transition metal is Pd and the preparation of the organic compound includes the formation of a C—N bond, the organic compound being prepared by Buchwald-Hartwig coupling of an aryl or heteroaryl halide or pseudohalide with an amine (Buchwald-Hartwig amination). 
   
   
       29 . The process-according to  claim 24  wherein the transition metal is Pd. 
   
   
       30 . The process according to  claim 24  which includes the formation of a C—O bond, the organic compound being prepared by coupling of an aryl or heteroaryl halide or pseudohalide with an alcohol. 
   
   
       31 . The process according to  claim 22  wherein organic compound is prepared by hydrodehalogenation of an aryl or heteroaryl halide. 
   
   
       32 . The process according to  claim 25  wherein the pseudohalogen or pseudohalide is selected from —COCl, —SO 2 Cl, —N 2 X, —OP(O)(OR) 2 , triflate, and tosylate. 
   
   
       33 . The process according to  claim 29  wherein the pseudohalogen or pseudohalide is triflate. 
   
   
       34 . The process according to  claim 25  wherein the halogen or halide is —Cl or —Br. 
   
   
       35 . A process for the preparation of a phosphine compound according to  claim 1  comprising the steps of: deprotonating a compound according to the formula HCp s  by the use of a strong base and reacting the resulting anion with a phosphinous halide according to the formula R′R″PX to form the phosphine compound R′R″PCp s , wherein Cp s , R′ and R″ are defined as above and X is Cl or Br. 
   
   
       36 . A process for the preparation of a phosphine compound according to  claim 1  comprising the steps of: deprotonating a compound according to the formula HCp s  by the use of a strong base and reacting the resulting anion with a phosphonous dihalide according to the formula R′PX 2  to form the phosphinous halide according to the formula Cp s R′PX, and alkylating the
 phosphinous halide with an appropriate organometallic alkylation agent to introduce the R″ group and to form the phosphine compound R′R″PCp s , wherein Cp s , R′ and R″ are defined as above and X is Cl or Br.   
   
   
       37 . A process for the preparation of a phosphonium salt according to  claim 1  comprising the steps of: preparing a phosphine compound as described above and converting the phosphine compound to its corresponding phosphonium salt by reaction with H + Y −  wherein Y −  is defined above.