A new C-3-symmetric chiral bisphosphine ligand containing a bioxazole backbone: highly enantioselective hydrosilylation of ketones

Abstract

C-2-Symmetric (4S,4'S)-2,2'-bis(o-diphenylphosphinophenyl)-4,4',5,5'- tetrahydro-4,4'-bi(1,3-oxazole) (1, Phos-Bidx) has been designed and synthesized as a chiral ligand for metal-catalyzed reactions. The Phos-Biox 1 was found to be an efficient ligand for rhodium(I)-catalyzed asymmetric reduction of prochiral acetophenones with diphenylsilane to give optically active secondary alcohols of up to 97% ee. (C) 1997 Elsevier Science Ltd. All rights reserved.