One-pot aqueous-phase synthesis of quinoxalines through oxidative cyclization of deoxybenzoins with 1,2-phenylenediamines catalyzed by a zwtterionic Cu(II)/calix[4]arene complex

The oxidative cyclization of deoxybenzoins with 1,2-phenylenediamines to form quinoxalines is catalyzed by a mononuclear copper(II) complex of zwitterionic calix[4]arene.