Novel synthesis of azocine,azepine,oxocine,and oxepine derivatives by palladium-catalyzed medium-ring formation from bromoallenes

摘要

Novel the efficient synthesis of medium-sized heterocycles such as azepine,oxepine,and benzo[d]azocine derivatives is described.Treatment of bromoallenes having a nucleophilic moiety with sodium alkoxide and a palladium(0) catalyst in the presence of an alcohol leads to regioselective formation of medium-sized rings at the central position of the allenic carbon.