Ligand-Free Reductive Amination via Pd-Coated Mechanocatalysis

Abstract

Reductive amination under direct mechanocatalysis was enabled by a sequential two-frequency milling protocol, separating imine formation and hydrogenation. Strongly hydrophobic liquid additives accelerated the reaction by enhancing water exclusion. Short-chain aliphatic amines were efficiently applied as solid hydrochloride salts under solvent-free conditions using H₂ and Pdcoated milling vessels.