Annulation π-extension of arenes with alkynes is an easy and sensible technique for the fast development of polycyclic fragrant compounds. Lately, some intriguingly transition-metal-catalyzed polycyclic arene syntheses have been described. Nevertheless, steel catalysts and exogenous oxidants have been important, which led to undesired by-products, low atom-economy and potential explosion threat. Herein, a straightforwardly electrochemical oxidation [3+2] or [4+2] annulation of imidazo[1,2-a]pyridines with alkynes to heterocyclic fragrant compounds underneath the steel and exogenous oxidant free circumstances has been completed. This inexperienced and sustainable methodology options wonderful regioselectivity, huge substrate adaptability and good useful group compatibility. Furthermore, a attainable mechanism has proposed on the bottom of radical-trapping, isotope labeling, KIE and cyclic voltammetry experiments.