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.
Ren et al. (Sat,) studied this question.