Harnessing the Umpolung Reactivity of 3-Pyrrol-1-yloxindoles: Iodine-Catalyzed Cross-Dehydrogenative Coupling for the Direct Synthesis of 3,3-Disubstituted Oxindoles

We report a molecular iodine-catalyzed cross-dehydrogenative coupling of 3-pyrrol-1-yloxindoles with <i>N,N</i>'-dialkylanilines that forges C(sp³)-C(sp²) bonds under mild, metal-free, and additive-free conditions. The reaction proceeds through α-iodination of 3-pyrrol-1-yloxindoles, enabling direct <i>para</i>-selective arylation of <i>N,N</i>'-dialkylanilines. The reaction operates efficiently in an acetonitrile/water medium in the presence of air, leading to the formation of 3,3-disubstituted oxindoles in high yields with short reaction times, broad functional group tolerance, synthetic applicability, and gram-scale feasibility.