Cu-catalyzed controllable C-H mono-/di-/triarylations of imidazolium salts for ionic functional materialsElectronic supplementary information (ESI) available: Experimental procedures, characterization data and copies of NMR spectra. See DOI: 10.1039/c7cc01076a

Herein the Cu-catalyzed direct C-H mono-, di- and triarylations of imidazolium salts with aryl iodides/bromides are accomplished for the first time. The unprecedented alkenylation and alkynylation are also realized using alkenyl and alkynyl iodides, respectively. Moreover, triarylated imidazolium salts with different substituents can be accessed in a modular and one-pot manner. This protocol provides an efficient tool for the assembly of diverse imidazolium-based ionic functional materials. As applicable examples, an electrochromic bisbenzimidazolium salt 7 and a photochromic triarylimidazolium salt 8 are easily obtained. The first Cu-catalyzed direct C-H mono-, di- and triarylations of imidazolium salts with aryl iodides/bromides are reported.