Copper-Catalyzed Asymmetric Hydrogenation of Aryl and Heteroaryl Ketones

Abstract

High throughput screening enabled the development of a Cu-based catalyst system for the asymmetric hydrogenation of prochiral aryl and heteroaryl ketones that operates at H₂ pressures as low as 5 bar. A ligand combination of (<i>R</i>,<i>S</i>)-<i>N-</i>Me-3,5-xylyl-BoPhoz and tris(3,5-xylyl)phosphine provided benzylic alcohols in good yields and enantioselectivities. The electronic and steric characteristics of the ancillary triarylphosphine were important in determining both reactivity and selectivity