The magnetic graphene oxide/NHC catalyzed aerobic direct amidation and cross-dehydrogenative coupling of aldehydes

Abstract

In this paper, the synthesis of a novel imidazolium based N-heterocyclic carbene (NHC) containing imidazopyridine substitutes using a three-component reaction is described. This compound was immobilized on magnetic graphene oxide (GO) to make a heterogeneous catalyst for the direct aerobic amidation of benzaldehyde derivatives under solvent-free conditions, as well as the intra- and intermolecular cross dehydrogenative coupling of aldehydes. In addition, the catalytic activity of the NHC catalyst was homogeneously studied in the presence of Fe₃O₄ nanoparticles under the same conditions, and showed good activity with lower yields than the heterogeneous catalyst.