Efficient One Pot Synthesis of Phenylimidazo[1,2-a]pyridine Derivatives using Multifunctional Copper Catalyst Supported on β-Cyclodextrin Functionalized Magnetic Graphene oxide

In this paper, a novel, “green”, efficient and atom-economical methodology for the synthesis of N-(alkyl)-2-phenylimidazo1,2-a]pyridin-3-amine derivatives based on copper catalyzed oxidative cyclization is presented. An efficient copper nanocatalyst was fabricated by immobilization of Cu on β-Cyclodextrin (βCD) functionalized magnetic graphene oxide nanosheets (denoted as Cu@βCD@MGO). This catalyst primarily oxidizes benzylic alcohols to aldehydes by aerobic O₂. The obtained aldehydes, in situ, takes part in a three component reaction with pyridin-2-amine and isocyanides to produce corresponding N-(alkyl)-2-phenylimidazo1,2-a]pyridin-3-amine derivatives. The catalyst was characterized by TEM, SEM, VSM, FT-IR, XRD, TGA and ICP. As an advantage, the catalyst showed to be highly recoverable and no appreciable leaching was observed after 10 runs.