Carbonylation (hydroformylation and hydroalkoxycarbonylation) of styrene in the presence of transition metal–ferrocene-based aminophosphine systems

Abstract

The PtCl 2(L)-type platinum complexes of the ferrocenyl ligands, ( S c, S m)-1-diphenylphosphino- α- N, N-dimethylamino[2,3]tetramethyleneferrocene ( 1) and ( S c, S m)-1,1′-bis(diphenylphosphino)- α- N, N-dimethylamino[2,3]tetramethylene ferrocene ( 2) have been synthesised. Both the ‘preformed’ and in situ catalysts have been used in hydroformylation of styrene. In spite of low enantioselectivities and activities, the ferrocenyl based systems proved to be of interest from theoretical point of view. The ligand influence on regio- and enantioselectivity has been investigated in systems containing either only one of the ferrocenyl ligands or one ferrocenyl ligand together with bdpp ((2 S,3 S)-2,4-bis(diphenylphosphino)pentane). The coordination of the respective ligands to platinum in the catalytic process can be deduced from results obtained with the ‘mixed ligand system’. The rhodium in situ catalysts containing either 1 or 2 are active in hydroformylation but the ee-s obtained with styrene are low. In the presence of ligand 1, the palladium-catalysed hydromethoxycarbonylation of styrene resulted in the predominant formation of the branched regioisomer, in case of 2 mostly the linear product was formed.