Direct reductive amination of aldehydes and ketones mediated by a thiourea derivative as an organocatalyst

Abstract

The direct reductive arylamination of arylaldehydes and ketones has been achieved using a selective imine activation by a hydrogen bond of a thiourea derivative. This mild, acid- and metal-free process requires a catalytic amount of N,N'-bis[3,5-bis(trifluoromethyl)phenyl]thiourea, the Hantzsch 1,4-dihydropydine diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate as hydride source and activated 5Å-molecule sieve as dehydrant. The method is adaptable for the synthesis of various amines.