The controllable highly selective reductive amination of carbonyl compound to primary amines, secondary imines and secondary amines is one of the challenging problems in organic synthesis. However, there are still many problems, such as difficulty in selective regulation, cumbersome and costly preparation of catalysts, and insufficient green solvents. In this work, commercial diatomite, activated carbon, Al₂O₃, TiO₂ and CeO₂ were employed to support nickel through a simple impregnation method. With H₂O as the green solvent, Ni/diatomite-400 can achieve controllable selective reductive amination of benzaldehyde to benzylamine, N-benzylidenebenzylamine and dibenzylamine only by regulating H₂ pressure and ammonia concentration. Accompanying spectroscopic characterizations and detailed mechanistic experiments illustrate that the synergistic effect of the appropriate proportion of Ni⁰/Ni²⁺ is the key to the successful modulation of selectivity, and this catalytic reaction mechanism was proposed. Moreover, the unique uniformly microporous structure of diatomite may facilitate the mass transfer and diffusion process of reactants, intermediates and products, leading to high catalytic efficiency. In addition, the catalyst also has excellent reuse performance and substrate universality. This work provides a new economical and efficient way for the reductive amination of carbonyl compounds in industry.

羰基化合物可控的高选择性还原胺化为伯胺、仲亚胺和仲胺是有机合成中具有挑战性的问题之一。但仍存在选择性调控困难、催化剂制备繁琐、成本高、绿色溶剂不足等问题。在这项工作中，采用商业硅藻土、活性炭、Al ₂ O ₃、TiO ₂和CeO ₂通过简单的浸渍方法来负载镍。Ni/diatomite-400以H ₂ O为绿色溶剂，可实现苯甲醛可控选择性还原胺化为苄胺，N-亚苄基苄胺和二苄胺仅通过调节H ₂压力和氨浓度。伴随的光谱表征和详细的机理实验表明，适当比例的Ni ⁰ /Ni ^{2+的协同效应}是成功调节选择性的关键，并提出了这种催化反应机理。此外，硅藻土独特的均匀微孔结构可以促进反应物、中间体和产物的传质和扩散过程，从而提高催化效率。此外，该催化剂还具有优异的再利用性能和底物通用性。该工作为工业上羰基化合物的还原胺化提供了一种经济高效的新途径。