Electrochemical Acceptorless Dehydrogenation of N-Heterocycles Utilizing TEMPO as Organo-Electrocatalyst

Catalytic acceptorless dehydrogenation (CAD) has been a basically important organic transformation to ubiquitous unsaturated compounds without the usage of a sacrificial hydrogen acceptor. In this work, we successfully developed the first electrochemical acceptorless dehydrogenation (ECAD) of N-heterocycles using TEMPO as the organo-electrocatalyst. We have achieved the catalytic dehydrogenation of N-heterocycles in an anode and the release of H-2 in a cathode using an undivided-cell system. A variety of six-membered and five-membered nitrogen-heteroarenes can be synthesized in good yields in this system. In addition, this protocol can also be used in the application of important molecular synthesis. Our electrochemical strategy provides a mild and metal-free route for (hetero)aromatic compounds synthesis via the CAD strategy.