New Synthetic Strategy for High-Enantiopurity N-Protected α-Amino Ketones and their Derivatives by Asymmetric Hydrogenation

Asymmetric hydrogenation of alpha-dehydroamino ketones catalyzed by a rhodium-chiral phosphorus ligand complex (up to 99% ee, 1000 TON), represents an efficient approach to chiral alpha-amino ketones. The reduction of alpha-amino ketones catalyzed by palladium on carbon (Pd/C) leads to amphetamine precursors with quantitative yield and no significant enantioselectivity loss.