Multicomponent cascade reaction: dual role of copper in the synthesis of 1,2,3-triazole tethered benzimidazo[1,2-a] quinoline and their photophysical studies

One-pot synthesis of 1,2,3-triazole tethered benzimidazo[1,2-a] quinolines through a multi-component reaction is demonstrated. The domino/cascade reaction proceeds via click reaction, in which 1,2,3-triazole motif augment methylene group reactivity/N-C bond formation/Knoevenagel condensation in sequence. Overall one C-C bond and three C-N bonds are formed in a single step. In addition, photophysical properties of these new compounds were studied and compound 5u emerged as good fluorogenic substrate with quantum yield similar to 0.21.