Supported Gold Nanoparticles for Efficient α‐Oxygenation of Secondary and Tertiary Amines into Amides

Abstract Although the α‐oxygenation of amines is a highly attractive method for the synthesis of amides, efficient catalysts suited to a wide range of secondary and tertiary alkyl amines using O 2 as the terminal oxidant have no precedent. This report describes a novel, green α‐oxygenation of a wide range of linear and cyclic secondary and tertiary amines mediated by gold nanoparticles supported on alumina (Au/Al 2 O 3 ). The observed catalysis was truly heterogeneous, and the catalyst could be reused. The present α‐oxygenation utilizes O 2 as the terminal oxidant and water as the oxygen atom source of amides. The method generates water as the only theoretical by‐product, which highlights the environmentally benign nature of the present reaction. Additionally, the present α‐oxygenation provides a convenient method for the synthesis of 18 O‐labeled amides using H 2 18 O as the oxygen source.