Efficient and green catalytic system incorporating new benzimidazolium salts for the Sonogashira cross‐coupling reaction

A number of novel benzimidazole salts were synthesized and their structures were determined using 1H NMR, 13C NMR and infrared spectroscopic techniques and elemental analysis. A catalyst system consisting of Pd(OAc)2 and copper nanoparticles in the presence of Cs2CO3 and incorporating the novel benzimidazole salts in poly(ethylene glycol) solvent significantly improved the yields of Sonogashira reactions between aryl halides and phenylacetylene under microwave irradiation in 10 min. We have developed an efficient, simple and environmentally benign catalytic system incorparating novel benzimidazole salts for the Sonogashira cross coupling reaction.the catalyst system consisting of Pd(OAc)2, CuNPc, benzimidazole salts, Cs2CO3 in PEG300 can be recycled at least tree times without loss of activity in short reaction time (10 min) without any palladium black formation.