L-Proline catalyzed one-step synthesis of 4,5-diaryl-2-1,2,3-triazoles from heteroaryl cyanostilbenes via [3+2] cycloaddition of azide.

Use of a novel reagent has been established for the synthesis of a series of 4,5-diaryl-2-1,2,3-triazoles ( and ) from cyanostilbene analogs of benzo[]thiophene, benzo[]furan and indole, catalyzed by L-proline via Lewis base-catalyzed one-step [3+2]cycloaddition of azide. This method provides an efficient, simple and environmentally benign procedure that affords good yields and relatively short reaction times.