Organometallic complex catalyst

Abstract

An organometallic complex catalyst is disclosed for use in a cross-coupling reaction. In formula (1), M is the coordination center and represents a metal atom such as Pd or an ion thereof. R1, R2, and R3 may be the same or different and are a substituent such as a hydrogen atom. R4, R5, R6, and R7 may be the same or different and are a substituent such as a hydrogen atom. X represents a halogen atom. R8 represents a substituent that has a n bond and 3-20 carbon atoms. With regard to the electron-donating properties of R1-R7 with respect to the coordination center M of the ligand containing R1-R7 that is indicated in formula (2), R1-R7 are arranged in combination such that the TEP value obtained from infrared spectroscopy shifts toward the high frequency side compared to the TEP value of the ligand of formula (2-1).

1 . A ligand which comprises a nitrogen-containing heterocyclic carbene structure represented by the following formula (2) and is a structural material of an organometallic complex catalyst for use in a cross-coupling reaction having a structure represented by the following formula (1). 
       
         
           
           
               
               
           
         
       
       wherein, in the formulae (1) and (2),
 M is a coordination center and represents any one of metal atoms selected from the group consisting of Pd, Pt, Rh, Ru and Cu, or an ion thereof; 
 R 2  and R 3  is optionally the same or different, and each represents at least one substituent selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, alkenyl group, an alkynyl group and an aryl group; 
 R 4 , R 5 , R 6  and R 7  is optionally the same or different, and each represents at least one substituent selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkenyl group, an alkynyl group, an aryl group, a hydroxy group, hydroxylate group, a thiocarboxyl group, a dithiocarboxyl group, a sulfo group, a sulfino group, an oxycarbonyl group, a carbamoyl group, a hydrazinocarbonyl group, an amidino group, a cyano group, an isocyano group, a cyanato group, an isocyanato group, a thiocyanato group, an isothiocyanato group, a formyl group, an oxo group, a thioformyl group, a thioxo group, a mercapto group, an amino group, an imino group, a hydrazino group, an aryloxy group, a sulfide group, a nitro group and a silyl group; 
 X represents a halogen atom which is capable of coordinating to the coordination center M; 
 R 8  represents a substituent having a π bond and 3 to 20 carbon atoms which is capable of coordinating to the coordination center M; 
 provided that, with regard to electron-donating property with respect to the coordination center M, R 1 , R 2 , R 3 , R 4 , R 5 , R 6  and R 7  are so combined and arranged that a TEP value (Tolman electronic parameter) [cm −1 ] obtained by an infrared spectroscopy of a ligand having a nitrogen-containing heterocyclic carbene structure represented by the following formula (2) which contains R 1  to R 7 , sifts toward a high frequency side compared to the TEP value [cm −1 ] of a ligand represented by the formula (2-1). 
 
       
         
           
           
               
               
           
         
       
       wherein, in the formula (2-1), R 4 , R 5 , R 6  and R 7  represent the same substituents as R 4 , R 5 , R 6  and R 7  in the formula (1). 
     
     
         2 . The ligand according to  claim 1 , wherein the TEP value of the ligand having the nitrogen-containing heterocyclic carbene structure represented by the following formula (2) is a value calculated from a stretching frequency of a carbonyl group obtained from an infrared absorption spectrum measured on an Rh carbonyl complex represented by the following formula (1-1), which is a complex where, in the formula (1), the portion of the -MR 8 X is substituted by —Rh (CO) 2 Cl. 
       
         
           
           
               
               
           
         
       
     
     
         3 . The ligand according to  claim 1 , wherein the organometallic complex catalyst represented by the formula (1) is used in a C—N cross-coupling reaction. 
     
     
         4 . The ligand according to  claim 1 , wherein the organometallic complex catalyst represented by the formula (1) has a structure represented by any one of the following formula (3), the formula (4) or the formula (5). 
       
         
           
           
               
               
           
         
       
       wherein, in the formulae (3) to (5),  i Pr represents an isopropyl group, Me represents methyl group.