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

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.