Paving the Way for Reductive Amination: Boosting Catalytic Ammonolysis of Schiff Base

The synthesis of primary amines through reductive/hydrogen-borrowing amination has garnered significant attention due to their wide application in the chemical industry. The key challenge of the reaction arises from two competing balances: the hydrogenations of primary imine versus Schiff base and the ammonolysis versus hydrogenation of Schiff base. The former has received extensive attention, and the latter, which directly determines the selectivity of primary amine, has recently emerged as a fresh view for enhancing catalytic performance. Thus, gaining insights into promoting the ammonolysis of Schiff base in the latter is becoming increasingly urgent for catalyst design. This Perspective starts by presenting the overall catalyst design principles and mainly discusses the influence of two balances on the selectivity and effective approaches to tackle them. A profound emphasis is placed on advancing the ammonolysis of Schiff bases through an in-depth understanding of structure-activity relationships and reaction mechanisms. Finally, three key directions deserving future investigations are provided. This distinctive view not only enhances the importance of comprehension of structure-activity relationships in primary amine synthesis but also unveils efficient avenues for catalyst design.