Asymmetric hydroformylation of vinylarenes with rhodium diphosphite catalyst

Chiral diphosphite based on binaphthol, which chelate with rhodium complexe s forming a nine-membered ring, led to an efficient hydroformylation of vin ylarenes, (e.e.. up to 46%), at moderate pressure and temperature reaction conditions. High pressure H-1 NMR experiments to elucidate intermediate met al species have been performed. (C) 2000 Published by Elsevier Science S.A.