Synthesis of Novel Benzimidazole Salts and Microwave-Assisted Catalytic Activity of in Situ Generated Pd Nanoparticles From a Catalyst System Consisting of Benzimidazol Salt, Pd(OAc)2, and Base in a Suzuki-Miyaura Reaction

Abstract

Novel benzimidazolium salts having N-benzyl or N-(4-substitutedbenzyl) groups were synthesized and their microwave-promoted catalytic activity for the Suzuki-Miyaura cross-coupling reaction were determined using in situ formed palladium(0) nanoparticles (PdNPs) from a catalytic system consisting of Pd(OAc)<inf>2</inf>/K<inf>2</inf>CO<inf>3</inf> in DMF/H<inf>2</inf> O. PdNPs were characterized by X-ray diffraction (XRD) pattern and particle size of in situ generated PdNPs from the Pd(111) plane was determined to be of diameter 19.6 nm by the Debye-Scherrer equation. Moreover, the yield of the Suzuki-Miyaura reactions with aryl iodides and aryl bromides was found to be nearly quantitative. The synthesized benzimidazole salts (1{5) were identified by 1H and 13C NMR and IR spectroscopic methods, and micro analysis. The molecular structure of 5 was also determined by X-ray crystallography.© TÜBITAK.