Cobalt-Catalyzed C–H Iodination of Aromatic Amides with Molecular Iodine through the Use of a 2-Aminophenyloxazoline-Based Bidentate-Chelation System

Abstract

The cobalt-catalyzed chelation-assisted C-H iodination of aromatic amides using molecular iodine as an iodinating reagent is reported. The reaction is carried out in an atmosphere of air and uses Co(OAc)₂·4H₂O as an efficient catalyst and 4-chloro-2-(4,5-dihydrooxazol-2-yl)aniline as a directing group. The reaction shows a wide functional group tolerance. Mechanistic studies suggest that the reaction proceeds through a different mechanism from that of our previously reported transformation in which a Co(II) catalyst/8-amino-5-choloroquinoline chelation system was used.