Thiourea-Catalyzed Reductive Amination of Ketones

Significance

An efficient, non-asymmetric, organocatalytic, direct reductive amination of ketones is described. This reaction proceeds under mild and acid-free conditions and is catalyzed by commercially available thiourea 1. It is assumed to proceed via activation of the in situ generated ketimine through hydrogen bonding interactions with thiourea 1 followed by reduction with commercially available Hantzsch ester 2. The reaction works well with a wide range of ketones in combination with aryl or heteroaromatic primary amines providing the corresponding secondary amines in moderate to excellent yields within 48 hours.