A series of new benzimidazolium chlorides bearing N,N′-benzyl, 2,4,6trimethylbenzyl and 2,4,6-triisopropylbenzyl substituents have been designed and synthesized from various o-phenylenediamines. Subsequently, corresponding Cu-based N-heterocyclic carbenes (NHCs) were generated in situ in the reaction medium which represents a new application of NHCs exploiting distinct catalytic property towards intermolecular cyclization reaction cascade for the synthesis of 2-aryl-3-(arylethynyl)quinoxalines from ophenylenediamines and terminal alkynes. The outcome of the cyclization reaction product depends upon the N,N′-substituents present on the benzimidazolium chlorides.