The synthesis and properties of perhydrobenzimidazol-2-ylidene liganded carbene complexes

In this study, silver(I) N-heterocyclic carbene complexes were synthesized by the reaction of 1,3-dialkylperhydrobenzimidazolyum salts with silver(I) oxide in dichloromethane. These complexes were used as carbene-transfer agents to synthesize of palladium(II) N-heterocyclic carbene complexes. The structure of all synthesized compounds were determined by using spectroscopic techniques such as 1H-NMR, 13C-NMR, IR and elemental analyses. The palladium complexes were tested as catalyst in the direct C5 arylation of 2-n-butylfuran, 2-n-butylthiophene and 2-n-propylthiazole with various aryl bromides at 130 oC in N,N-dimethylacetamide (DMAc) for 1h. The arylation reactions were proceed selectively at C5 position of heteroaromatic compounds and the corresponding coupling products were obtained in good yields.