Highly enantioselective asymmetric hydrogenation of alpha-phthalimide ketone: an efficient entry to enantiomerically pure amino alcohols.

A new type of alpha-phthalimide ketones was hydrogenated in excellent enantioselectivity by using a Ru-(C3-TunePhos) complex as the catalyst. Up to 10 000 turnovers have been achieved in more than 99% ee in the hydrogenation reaction. A dynamic kinetic resolution study for the synthesis of threonine was performed, and high anti selectivity (>97:3) was observed for the first time. An efficient method to synthesize enantiomerically pure amino alcohols has been developed.