Effective synthesis of symmetrical oxygen- and nitrogen-heterocycles from electron-deficient alkynes via the catalysis of electrogenerated base and Fe3+ ions

An efficient method has been developed for the synthesis of oxygen- and nitrogen-heterocycles from electron-deficient alkynes and alcohol or amines via electrochemically induced two-step process. The first step involves that the electrogenerated base (EGB) catalyzes hydroalcoholization or hydroamination process. In the second step, Fe3+ ions and strong bases electrogenerated can synergically catalyze the cyclization process to give symmetrical heterocycles. Some key factors were investigated and the reaction mechanism was discussed.