Recyclable Metallic Imidazolium-Based Ionic Liquid-Catalyzed Selective Mono- and Double-Hydroboration in Water

The recyclable metallic imidazolium-based ionic liquid-catalyzed mono-hydroboration of imines, double-hydroboration of imine with aldehyde, and double-hydroboration of aniline with glutaric dialdehyde in the presence of HBpin in water is described for the first time. The ionic liquid [BMIm][FeCl4] showed excellent activity, high selectivity, and good recyclability for the catalytic imine hydroborations. This catalytic system widely tolerated various functional rings and unsaturated groups without additional reduction. Furthermore, the metallic ionic liquid [BMIm][FeCl4] could be reused for more than 15 runs in water without decay of the catalytic activity.