Electrochemical Oxidative Ring Opening of 1‑Acetylindoline-3-one to Access α‑Ketoamides

The synthesis of α-ketoamides through oxidative ring opening of 1-acetylindoline-3-one under electrochemical conditions is reported. In an undivided cell, the reaction proceeds via the formation of an iminium ion intermediate, nucleophilic attack by a hydroxide ion, and subsequent ring opening through pre-existing C–N bond cleavage. The reaction in the presence of H218O confirms that the amidic oxygen originated from the moisture present in the medium.