One-Pot N-α-C(sp3)–H Bond Functionalisation Cascade for the Synthesis of Polysubstituted Imidazoles

A one-pot eco-friendly oxidative N-α-C(sp3)–H bond functionalisation of arylmethylamines for the synthesis of tetrasubstituted imidazoles is demonstrated. The substrate scope of these amines has been well-explored with different substrates, such as 1,2-diketones, an α-hydroxy ketone and phenylacetophenone. In the presence of FeCl3 catalyst and green oxidant O2, the easily accessible substrates afforded tetrasubstituted imidazoles in up to 94% yield.