Efficient C–H Functionalisation of Thiazole Derivatives Catalyzed by Pd–NHC Complexes

Abstract In this study, benzimidazolium salts were synthesized by introducing a bulky N -(2-ethylhexyl) benzimidazole, while various aryl substituents were incorporated onto the second nitrogen. These salts were employed as N-heterocyclic carbene (NHC) precursors and reacted with Pd(OAc)₂ to afford a series of [PdCl₂(NHC)₂]-type palladium(II) NHC complexes. The catalytic activity of the synthesized complexes were evaluated in the direct C–H arylation of thiazole-derived heteroaromatic compounds.