Asymmetric Hydrogenation of β-Secondary Amino Ketones Catalyzed by a Ruthenocenyl Phosphino-oxazoline-ruthenium Complex (RuPHOX-Ru): the Synthesis of γ-Secondary Amino Alcohols

A ruthenocenyl phosphino-oxazoline-ruthenium complex (RuPHOX-Ru) was applied successfully to the asymmetric hydrogenation of beta-secondary amino ketones, directly affording the corresponding chiral gamma-secondary amino alcohols in up to 99% yield and with 99% ee. Reaction with beta-(benzylamino)-1-phenylpropan-1-one could be performed on a gram-scale with a relatively low catalyst loading (up to 2000 S/C). The resulting hydrogenated product could be used for the synthesis of synthetically useful compounds.