Substrate-Induced\nCooperative\nIonic Catalysis: Difunctionalization\nof Indole Derivatives Employing Dimethyl Carbonate

The global urge to adopt sustainable\nchemistry has resulted in\nthe development of more environmentally benign strategies (EBS) that\nuse CO<sub>2</sub> and CO<sub>2</sub>-derived chemicals in a step-economic\nmanner. In this context, we investigated a dual C–H methylation\nand (CO)-methoxylation of indole derivatives using dimethyl\ncarbonate (DMC) in the presence of catalytic amounts of Cs<sub>2</sub>CO<sub>3</sub>. Mechanistic insights include DMF-assisted, DMC-induced\ncooperative ionic catalysis, which allows DMC to act as both a nucleophilic\nand an electrophilic precursor, resulting in (CO)-methoxylation\nand C–H methylation of <i>N</i>-benzylindolyl ketones.