Copper immobilized onto the polyvinyl imidazole coated magnetic graphene oxide as an efficient heterogeneous catalyst for A3 and C–X cross-coupling reactions

Abstract

Copper immobiolized onto the polyvinyl imidazole coated magnetic graphene oxide [MGO@PVimCu(I)] was synthesized and characterized by various analytical methods such as FT-IR, XRD, TGA, TEM, FESEM, VSM and ICP-OES. According to the FE-SEM and TEM results, the size of the snared nanoparticles in the polymer matrix was about 50–90 nm and the surface of the catalyst was rough. The loading percentage of copper onto the polyvinyl imidazole coated MGO was determined to be 17% using ICP-OES, which is far better than the many known metal-based heterogeneous catalysts. In the catalytic activity scrutiny, A³ coupling reaction for the preparation of propargylamines and coupling reaction of aryl halides with nucleophiles were aimed. In the presence of MGO@PVimCu(I), the corresponding products were gained in these reactions with moderate to excellent yields in aqueous medium (50–99%). This method demonstrates several considerable benefits including product yields, the use of various substrates, easy work-up, separation of catalyst by a simple external magnet, reusability of catalyst (at least four cycles), eco-friendliness, and avoidance of using any toxic solvent. The results of this study have shown that this catalyst can be a suitable candidate for other organic transformations.

Graphical abstract