Room-Temperature Chemoselective Reduction of 3-Nitrostyrene to 3-Vinylaniline by Ammonia Borane over Cu Nanoparticles.

We report a new strategy of controlling catalytic activity and selectivity of Cu nanoparticles (NPs) for the ammonia borane initiated hydrogenation reaction. Cu NPs are active and selective for chemoselective reduction of nitrostyrene to vinylaniline under ambient conditions. Their activity, selectivity, and more importantly, stability are greatly enhanced by their anchoring on WO2.72 nanorods, providing a room-temperature full conversion of nitrostyrene selectively to vinylaniline (>99% yield). Compared with all other catalysts developed thus far, our new Cu/WO2.72 catalyst shows much enhanced hydrogenation selectivity and stability without the use of pressured hydrogen. The synthetic approach demonstrated here can be extended to prepare various M/WO2.72 catalysts (M = Fe, Co, Ni), with M being stabilized for many chemical reactions.