A cost-effective, highly regioselective and metal-free version for the synthesis of indolizine derivatives by means of Tf2O-mediated cascadereaction of pyridyl-enaminones and thiophenols/thioalcohols under mild reaction conditions has been reported. Diverse electron-rich indolizine derivatives could be obtained in up to 94% yield via the selective 1,4-addition of vinyl iminium triflate tandem cyc