Copper-mediated aerobic intramolecular C-H amination and oxidation of indoles.

The regioselective functionalization of C-H bonds and the utilization of molecular oxygen (O2) as a terminal oxidant remain tremendous challenges in synthetic organic chemistry. Herein, a copper-mediated strategy for the construction of fused indolo-imidazolinone frameworks has been developed from 2-(1H-indol-1-yl)aniline derivatives through an initial intramolecular C(sp2)-H amination at the indole C-2 position, followed by a mechanistically distinct aerobic C-3 ketonization driven by molecular oxygen. This operationally simple protocol highlights the dual role of copper in C-N bond formation and subsequent oxidation, offering a practical route to synthetically valuable indole-fused heterocycles.