Gold Catalysts Open a New General Chemoselective Route to Synthesize Oximes by Hydrogenation of α,β-Unsaturated Nitrocompounds with H₂

The unprecedented chemoselective reduction of α,β-unsaturated nitroalkenes to oximes using hydrogen has been achieved with gold nanoparticles supported on TiO2. In contrast to the excellent catalytic performance of gold, related palladium and platinum catalysts are unselective, leading to the reduction of CC double bond as well as the reduction of the NO2 to NH2. The selectivity of Au/TiO2 for the formation of oximes opens the way for the general use of the Henry reaction in organic synthesis.