Accessing aryl azides via copper powder-catalyzed cross-coupling of arylboronic acids with the hypervalent azido-iodine reagent

The cross-coupling reaction of arylboronic acids with the hypervalent azido-iodine reagent ABZ(I) in the presence of a catalytic amount of copper powder was found to give aryl azides in high yields. This transformation is ligand- and base-free and has a good functional group tolerance, with ABZ(I) playing a bifunctional role as an oxidant and an azido source. DFT calculations were performed to obtain mechanistic insights into this transformation.