N═N Coupling and Rearrangement of Arylamines with N-Nitrosoaromatics: Synthesis of Unsymmetric Azobenzenes

This paper presents an efficient strategy for constructing unsymmetric azobenzenes through a cascade reaction between arylamines and N-nitrosoaromatics. This process proceeds via initial N═N bond formation, followed by N-N bond cleavage and concomitant C-N bond formation. The method employs stable and readily available arylamines and N-nitrosoaromatics as starting materials, producing water as the sole byproduct. Additional advantages include mild reaction conditions, high atom economy, operational simplicity, and broad substrate scope with excellent functional group tolerance.