[摘要]:An unprecedented TfOH-promoted tandem ring-closure-aryl-migration of 2'-amino chalcone epoxide leading to 3-aryl-4(1H)-quinolones (azaisoflavones) was achieved. The outcome of the reaction was confirmed by NMR analysis and rationalized through the intermediacy of a phenonium ion. This synthetic protocol furnishes azaisoflavones straightforwardly from simple starting materials under mild conditions. |