Electrochemical Oxidative N–N Coupling to Construct Benzo[ c ]cinnolines and Azoarenes

A highly efficient electrochemical oxidative dehydrogenative N–N coupling of arylamines to selectively provide benzo[ c ]cinnolines and azoarenes has been investigated. In this simple process, various functional groups were tolerated under mild reaction conditions without additional metal or oxidant, and the practicality of the protocol was demonstrated by the preparation of benzo[ c ]cinnolines on a gram scale and later derivatization. Mechanism of studies shows that the reaction proceeds via a radical pathway with the hydrazine compound as an intermediate. Additionally, the base plays an important role in this transformation, potentially facilitating the dehydrogenation process.