Electrochemical Intramolecular Dehydrogenative Coupling of N-Benzyl(thio)amides: A Direct and Facile Synthesis of 4H-1,3-Benzoxazines and 4H-1,3-Benzothiazines

摘要

The electrochemical dehydrogenative cyclization of N-benzylamides was investigated with a Pt plate anode and graphite rod cathode in an undivided cell at room temperature. The oxidative degradation of the products was suppressed successfully and 4H-1,3-benzoxazines were obtained regardless of the substituents at the benzylic position. This method also allowed for the preparation of 4H-1,3-benzothiazines.