ZnCl2/PhI=O Mediated Selective ortho-Chlorination of Amides

Abstract: A new ortho-chlorination system consisting of zinc(II) and hypervalent iodine(III) reagent was developed for ortho-chlorination of amides, and the desired products were obtained in moderate to good yields (38-85%). This highly facile and convenient methodology is tolerant of aromatic amide and alkyl amide with diverse substituted groups. A plausible mechanism has been illustrated, in which carbocation rearrangement and metal salt coordinate facilitated orthochlorination are involved.