Efficient and Mild Reductive Amination of Carbonyl Compounds Catalyzed by Dual-Function Palladium Nanoparticles

Primary amines are valuable building blocks for a large number of chemicals, developing efficient synthetic routes toward primary amines and particularly those proceeding under mild conditions are highly desirable and rather challenging. Presented here is a highly efficient procedure enabling itself to proceed in H₂O using H₂ of 1 atm (0.1 MPa) for the reductive amination of carbonyl compounds. Several palladium-based nanoparticle (Pd-NP) catalysts were prepared, and one emerged to be the most suitable and classified as nanoparticles, due to its high catalytic activity, reactions were allowed to proceed at room temperature using NH₃, and the corresponding primary amines can be afforded with yields of up to 99%. Some control reactions were carried out, revealing that H₂ is pivotal for activating the Pd-NPs. The fact that the Pd-NPs can catalyze both reductive amination of carbonyl compounds and hydrogenation of imines proves Pd-NPs to be a dual-function catalyst, and a plausible mechanism was proposed.