Copper‐Catalyzed Selective Oxidative Acylation of Secondary Anilines with Ethyl Glyoxalate: Domino Synthesis of Indoline‐2,3‐diones

A novel, easy and useful copper‐catalyzed selective acylation of secondary anilines with ethyl glyoxalate has been developed, and the corresponding indoline‐2,3‐dione derivatives were prepared. The procedure comprises the sequential intermolecular copper‐catalyzed selective oxidative ortho ‐site aromatic acylation of the NH group in secondary anilines and intramolecular nucleophilic attack of the NH group to the ester. The inexpensive, easy and efficient method should provide a new strategy for synthesis of dicarbonyl compounds.