2‑Oxindole Acts as a Synthon of 2‑Aminobenzoyl Anion in the K2CO3‑Catalyzed Reaction with Enones: Preparation of 1,4-Diketones Bearing an Amino Group and Their Further Transformations

A convenient approach for the synthesis of 1,4-diketones bearing an amino group has been developed through the K2CO3-catalyzed reaction of 2-oxindoles with enones with the assistance of atmospheric O2 via sequential Michael addition–oxidation–ring-cleavage process. The further intramolecular reaction leads to the formation of benzoazepinone, quinoline, and 3-oxindole derivatives.