Microwave-assisted conversion of carbonyl compounds into formylated secondary amines: new contribution to the Leuckart reaction mechanism in N-methylformamide

The reductive amination of several carbonyl compounds (Leuckart reaction) has been performed using N-methylformamide and microwave technology. Under these conditions, a new mechanism is proposed via the initial formation of an imine, followed by reduction to the amine by 'in situ' generated formic acid, and further formylation of the amine. Using this methodology, the formyl derivatives of several secondary amines were obtained in good to excellent yields.