N-Benzyl-norephedrine derivatives as new, efficient ligands for ruthenium-catalyzed asymmetric transfer hydrogenation of functionalized ketones

摘要

Significant catalytic activities (up to 600 h~(-1) at 20 deg C) and enantiomeric excesses ranging from 56 to 89% for the asymmetric transfer hydrogenatio of #beta#-ketoesters,methoxyacetone and 2-acetylpyridine to the corresponding alcohols are achieved in the presence of catalytic combinations of [RuCl_2 (#eta#~6 -arene)]_2 and N-substituted derivatives of (1S,2R)-norephedrine such as N-benzyl-norephedrine and N-(4-biphenyl)methyl-norephedrine.