Synthesis of Quinoxaline-Linked Bis(Benzimidazolium) Salts and Their Catalytic Application in Palladium-Catalyzed Direct Arylation of Heteroarenes

In this study, quinoxaline-linked bis(benzimidazolium) salts were synthesized as bis-N-heterocyclic carbene (NHC) precursors. These bis(NHC) precursors were used as multidentate ligands for the construction of bi(hetero)aryls by palladium-catalyzed direct C-H activation process. The in situ prepared palladium complexes by mixtures of the Pd(OAc)(2) and the bis(NHC) precursors were used as the catalyst for direct C-H activation of heteroarenes. These catalytic system exhibited a modest catalytic activity in the direct C-H activation of five-membered heteroarenes with a wide range of (hetero)aryl bromides.