Patent ID: 6914161

Claim:
Process for the preparation of a multidentate phosphine compound represented by the general formula (1), wherein the two carbon atoms forming the bridging group between the 9-phospha-bicyclononane groups each are substituted by one hydrogen atom, and further, independently, are substituted by substituents A and B, which may be linked together so as to form a ring with the bridging carbon atoms and are selected from the group consisting of C 1 to C 12 alkyl, C 1 to C 12 alkoxy, carboxylic esters thereof and amides thereof, C 6 to C 14 aryl and C 4 to C 14 heteroaryl groups, and wherein the bicyclononane groups optionally may be substituted by two lower alkyl (C 1 to C 6 ) or phenyl substituents at positions (1,4), (1,5) or (2,6), which comprises reacting a 9-phosphabicyclononane, in the presence of an acidic catalyst, with an alkenylmonophosphine compound of formula (2) wherein any of the 9-phospha-bicyclononane groups in the compounds of formula (1) and/or the compounds of formula (2) may optionally be substituted by two lower alkyl (C 1 to C 6 ) or phenyl substituents at positions (1,4), (1,5) or (2,6) wherein R 1 and one of the R 2 and R 3 represent a substituent selected from the group consisting of C 1 to C 12 alkyl, C 1 to C 12 alkoxy, carboxylic esters thereof and amides thereof, C 6 to C 14 aryl and C 4 to C 14 heteroaryl groups and the other of the R 2 and R 3 represents a hydrogen atom.