Iodine-induced cyclization of γ, δ-unsaturated secondary thioamides 1 proceeded regio-(5- exo-trigonal) and chemo-(sulfur-carbon bond formation) selectively, providing iminothiolactones 2, which were converted in two-step sequences (dehydroiodination and N- acetylation) into 2-acetoamidothiophenes 4. This procedure was performed in one flask to afford polysubstituted 2-aminothiophenes.
