Facile and Efficient Synthesis of Primary Amines via Reductive Amination over a Ni/Al2O3 Catalyst

The production of primary amines with high efficiency and selectivity employing appropriate catalysts is of central importance yet challenging. Here, we reported Ni nanoparticles supported on γ-Al2O3 as a highly active heterogeneous catalyst for the synthesis of primary amines through reductive amination in the presence of ammonia and hydrogen. The resulting Ni/Al2O3 catalyst exhibited outstanding performance for the selective reductive amination of carbonyl compounds (aldehydes and ketones) involving aromatic, branched, and purely aliphatic chemicals converted into their corresponding primary amines with excellent yields (87∼99%) under mild reaction conditions (100 °C and 2 MPa), which was attributed to the synergistic effect of strong metal–support interaction combined with medium acidic sites. In particular, the yield of primary amines for earth-abundant Ni catalysts was superior to that for precious metal catalysts (Ru, Rh, and Pd), suggesting that the Ni/Al2O3 catalyst could be a promising candidate for the industrial production of amines.