Asymmetric Hydrogenation. Rhodium Chiral Bisphosphine Catalyst

Abstract

Enantiomeric excesses of 95-96% are obtained by the asymmetric hydrogenation of a-acylaminoacrylic acids. The olefin configuration, whether E or Z, has a profound influence on the rate and stereospecificity. Excellent selectivity (~90% ee) was obtained with an a-enol ester, which is the first outstanding resuit with a nonamide substrate. A catalyst picture is presented and the stereochemical results are discussed. © 1977, American Chemical Society. All rights reserved.