N-Heterocyclic carbene–chromium-catalyzed alkylative cross-coupling of benzamide derivatives with aliphatic bromides

Abstract

Described here is a chromium-catalyzed alkylative cross-coupling of benzamide derivatives with aliphatic electrophiles under mild conditions. This reaction was promoted by a low-cost and air-stable chromium(III) chloride salt combined with an N-heterocyclic carbene ligand and phenylmagnesium bromide as a reductant, and probably occurred with low-valent chromium involved in the catalytic cleavage of the ortho-C–H bonds of the benzamide, followed by coupling with the alkyl bromide through a radical-involving mechanism.