Synthesis of new C-2-symmetsic bioxazoles and application as chiral ligands in asymmetric hydrosilylation

Abstract

New C-2-symmetric chiral (4S,4'S)-bioxazoles 3a and 3b, possessing chirality on their backbone, were synthesized efficiently starting from L-tartaric acid. The structure of 3a was determined by X-ray crystal structure analysis. With these novel chiral bioxazole ligands, as a preliminary investigation for their effects on the enantioselectivity, rhodium(I)-catalyzed enantioselective hydrosilylations of acetophenone were carried out. (C) 1997 Published by Elsevier Science Ltd.