Asymmetric Synthesis of α-Amino Ketones by Brønsted Acid Catalysis.

The highly efficient, regioselective, and enantioselective transfer hydrogenation of α-keto ketimines and reductive amination of diketones by Brønsted acid catalysis is described. A series of chiral α-amino ketones is prepared in high yields (up to >99%), excellent regioselectivities (up to >99:1), and enantioselectivities (up to 98% ee). This method has broad substrate scope.