Iridium/graphene nanostructured catalyst for the N-alkylation of amines to synthesize nitrogen-containing derivatives and heterocyclic compounds in a green process

A facile iridium/graphene-catalyzed methodology providing an efficient synthetic route for C–N bond formation is reported. This catalyst can directly promote the formation of C–N bonds, without pre-activation steps, and without solvents, alkalis and other additives. This protocol provides a direct N-alkylation of amines using a variety of primary and secondary alcohols with good selectivity and excellent yields. Charmingly, the use of diols resulted in intermolecular cyclization of amines, and such products are privileged structures in biologically active compounds. Two examples illustrate the advantages of this catalyst in organic synthesis: the tandem catalysis to synthesize hydroxyzine, and the intermolecular cyclization to synthesize cyclizine. Water is the only by-product, which makes this catalytic process sustainable and environmentally friendly.