Hydrogenation of nitrile to primary amine with carbon-coated Ni/NiO@C catalyst under mild conditions

Reusable catalysts based on non-noble metals with broad applicability used in nitrile catalytic hydrogenation synthesis are a key to a more sustainable production of primary amine. Herein, a simple and efficient carbon-coated non-noble metal nickel-based catalyst (Ni/NiO@C-600-200-1-H2O) was prepared for the hydrogenation of aromatic substituted nitrile to aromatic substituted amine under mild conditions (120 °C, 10 bar H2, 4 h). The carbon-coated catalyst has excellent anti-agglomeration ability due to its special carbon-coated metal structure, which can enhance the cyclic stability of the catalyst. Several aromatic substituted nitriles containing diffident functional groups such as halogen, methyl, methoxy, etc. are well tolerated in the Ni-based catalytic hydrogenation and can be converted to the corresponding amine with high activities (conversion rate over 99%, product selectivity reached 98.25%). Moreover, the catalyst can be easily recovered and reused due to its magnetic nature. In addition, we also applied the catalyst to the continuous flow reactor to catalyze benzylamine hydrogenation of benzonitrile under optimized conditions, the conversion rate and selectivity of the reaction were > 99%, and the continuous operation time was up to 31 h.