THE ROLE OF ADDITIVES IN PLATINUM-CATALYZED HYDROFORMYLATION

A study has been made of hydroformylation of styrene derivatives catalysed by several Pt-bisphosphine systems modified with various additives. The chain length of the chelating phosphines and the quality of the Lewis-acid type additives strongly influences the activity and the chemo- and regio-selectivity of the catalysts. The most active PtCl2(bisphosphine) + SnCl2 system was modified with amines of different basicities, and it was found that a strong base such as Et3N stops the catalytic reaction by abstracting HSnCl3 from the active platinum species. This reaction was monitored by NMR spectroscopy. Complexation of the chiral aminophosphine ((S)-(-)-N,N-dimethyl-1(2′-diphenylphosphinophenyl)-ethylamine, (S)-(-)-AMPHOS) with platinum has also been studied, and a chemical shift anisotropy relaxation mechanism observed. © 1990.