Intramolecular aminolysis of 2-aminochalcone epoxides using InBr 3 or BiCl3 as efficient catalysts

Abstract

In the synthesis of aza-flavanone derivatives, several metal halides were screened for their catalytic activity. Among them, BiCl3 and InBr3 catalyze the ring opening of 2-aminochalcone epoxides followed by intramolecular aminolysis under mild conditions. The reactions proceed efficiently at room temperature to afford highly functionalized 2-aryl-3-hydroxy-2,3-dihydro-4-quinolones (aza-flavanones) in excellent yields (82-92%). Intermolecular aminolysis of 2-aminochalcone epoxides with aniline derivatives failed under the same catalytic conditions. © 2013 Copyright Taylor and Francis Group, LLC.