摘要:
Axially 4,4'-di-tert-butyl TunePhos-type chiral diphosphine ligand was designed and synthesized by means of central-to-axial chirality transfer. Up to 99% and 98% ee have been achieved in Ru-catalyzed hydrogenation of beta-alkyl and beta-aryl-substituted beta-keto esters, respectively. (C) 2008 Elsevier Ltd. All rights reserved.