Rh-Catalyzed Environmentally Benign Selective Hydrogenation of a Broad Variety of Functional Groups Using Al-Water as a Hydrogen Source

Supported rhodium catalysts were screened to catalyze the one-step hydrogenation of a broad variety of functional groups. The results show that 5% Rh/Al2O3 and 5% Rh/C performed well in controlling selective hydrogenation under the desired amount of time and temperature. In this regard, partial and full hydrogenation were achieved by controlling reaction time or temperature. In addition to aliphatic C–C, C–N, C–O, and N–O multiple bonds, the applicability of this method was demonstrated by the hydrogenation of C=C double bonds of arenes, which is considered challenging. Importantly, the Al-H2O system producing hydrogen in situ and the high, controllable selectivity make this protocol environmentally benign and highly efficient.