Heterogeneous Catalytic Aerobic Oxidation of Primary Amines to Amides Using Unsupported Nanoporous Palladium Catalyst

An efficient and highly selective heterogeneous catalyst system for aerobic oxidation of primary amines was developed using unsupported palladium nanopores (PdNPore). A variety of aromatic, aliphatic, and heterocyclic primary amines were oxidized to the corresponding amides in satisfactory to excellent yields using ambient air as an oxidant. No palladium was leached from PdNPore during the oxidation reaction. The catalyst could be readily recovered and reused without a decrease in catalytic activity. The kinetic studies and control experiments demonstrated that nitrile acts as an intermediate, which undergo hydration to afford amide as the final product.