Journal of the American Chemical Society, Vol.129, No.45, 13798-13798, 2007
N-heterocyclic carbene-catalyzed redox amidations of alpha-functionalized aldehydes with amines
A catalytic method for the direct synthesis of carboxylic acid amides from amines and alpha-functionalized aldehydes is possible through the synergistic role of a N-heterocyclic carbene catalyst and imidazole, affording amides via activated carboxylates catalytically generated via an internal redox reaction of the aldehyde substrates. The use of imidazole or other N-heterocycles as an additive is essential to overcoming imine formation and serves as a uniquely reactive substrate for the generation of an acyl imidazolium intermediate that is converted to the final amide product.