Nitrogen-directed ketone hydroacylation: Enantioselective synthesis of benzoxazecinones

Abstract

We report a nitrogen-directed ketone hydroacylation to furnish 8-membered N-containing lactones (benzoxazecinones) in high yields and high enantiomeric excesses. In a model study, a comparison was made between nitrogen, oxygen and sulfur directing groups and it was found that nitrogen promoted faster hydroacylation. Moreover, the amine directing group completely suppressed competitive decarbonylation. This catalytic transformation generates a relatively unexplored class of nitrogen heterocycles, namely benzoxazepinones and benzoxazecinones.