A study has been made of asymmetric hydroformylation of styrene with PtCl2(PPh3)2 + bisphosphine + SnCl2 (bisphosphine: BDPP = (-)-(2S,4S)-2,4-bis(diphenylphosphino)pentane or DIOP = (-)-(4R,5R)-2,2-dimethyl-4,5-bis(diphenylphosphinomethyl)-1,3-dioxolane) and PtCl2(bisphosphine) + PPh3 + SnCl2 catalysts prepared "in situ". The presence of an excess of the phosphine ligand slightly lowered the reaction rate, but the enantioselectivity of these systems is significantly higher than those involving PtCl(SnCl3)(bisphosphine) catalysts. Under mild reaction conditions 88.8% enantiomeric excess was achieved. Replacing SnCl2 in these catalysts by CuCl2 or CuCl gave a new homogeneous catalytic system which is active at higher reaction temperature (> 100°C), but has a rather moderate enantioselectivity.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry