Direct l-Proline-Catalyzed Asymmetric α-Amination of Ketones

The first direct catalytic asymmetric alpha-amination of ketones catalyzed by l-proline has been developed. The reactions proceed with various azodicarboxylates as the nitrogen source in high yields and excellent enantioselectivities (up to 99% ee). The scope and potential of the reaction are demonstrated by further transformation of the alpha-hydrazino ketones formed to both optically active syn and anti-alpha-amino alcohol derivatives.