Practical mutual transformation of azobenzene and hydrazobenzene using porous BN supported Cu nanoparticles as a redox catalyst

We report for the first time a stable and easily recoverable catalytic system that achieves an entirely mutual transformation of azobenzene and hydrazobenzene under very mild conditions. [Display omitted] •A stable catalytic system achieves hydrogenation/dehydrogenation cycles.•Hydrogenation/dehydrogenation reactions proceed under very mild conditions.•Dehydrogenation reaction proceeds with hydrogen as the by-product. Azobenzene and hydrazobenzene compounds are essential intermediates for synthesizing pharmaceuticals and dyes. Meanwhile, the hydrazobenzene/azobenzene couple is a potential hydrogen storage system when both the dehydrogenation of hydrazobenzene and the hydrogenation of azobenzenes can be achieved under mild reaction conditions. In this work, we report an entirely mutual transformation of azobenzene and hydrazobenzene under very mild conditions using porous BN supported Cu nanoparticles (Cu/PBN) as the catalyst for the first time. Direct oxidative dehydrogenation reaction proceeded in the open air with the removal of molecular hydrogen as the by-product and a wide range of hydrazobenzenes readily undergoes dehydrogenation, resulting in an excellent yield of the corresponding azobenzene.