Highly Enantioselective Asymmetric Hydrogenation of α-Phthalimide Ketone: An Efficient Entry to Enantiomerically Pure Amino Alcohols

摘要

Chiral amino alcohol is a key function group in biologically active molecules. Consequently, the construction of this structural motif attracts extensive efforts by organic chemists. Developing highly enantioselective methods to prepare amino alcohols with efficiency remains one of the major challenges. Without any doubt, asymmetric hydrogenation is the most powerful method to make chiral molecules. For example, asymmetric hydrogenation of ketones is regarded as the most successful method to form chiral alcohols. However, there are few successes in ketone hydrogenation with an α-NH_2 group. Very recently, Noyori applied RuCl2(bisphosphine)(1,2-diamine) complexes, efficient catalysts for reducing unfunctionalized ketones, to the asymmetric hydrogenation of amino ketones in the presence of a strong base. Herein, we describe our highly enantioselective asymmetric hydrogenation of α-phthalimide ketones to form α-phthalimide alcohols, the masked α-primary amino alcohols.