Synthesis of 3-oxadiazole-substituted imidazo[1,2-a]pyridines by nickel immobilized on multifunctional amphiphilic porous polysulfonamide–melamine

Abstract

Due to the fact that developing sustainable processes and applying eco-friendly heterogeneous catalysts have become widely significant, researchers have paid great attention to synthesizing new porous amphiphilic stabilizers in order to anchor metal nanoparticles (NPs). In this sense, a porous polysulfonamide–melamine amphiphile (PEMA–PSA), as a novel organic support system, has been successfully synthesized using the silica template method. The present research proposes the immobilization of Ni nanoparticles inside the polymer pores (PEMA–PSA@Ni) for better nanoparticle performance. PEMA–PSA@Ni was implemented as an inexpensive and reusable catalyst for the synthesis of a novel category of oxadiazoles (3-oxadiazole-substituted imidazo[1,2-a]pyridines). In this regard, benzhydrazide and 3-iodo-[1,2-a]pyridines via isocyanide insertion/cyclization were reacted in the presence of PEMA–PSA@Ni under mild conditions. It is worth mentioning that the catalyst had a very good performance due to the following features: greatly dispersed Ni, good surface area, unique amphiphilic structure and convenient recovery. The most significant advantages of this method include: simple operation, short reaction time, and wide substrate scope.