Synthesis of Substituted Thiophenes through Dehydration and Heterocyclization of Alkynols

A protocol was described for obtaining a variety of substituted thiophenes with functional potential viametal-free dehydration and sulfur cyclization of alkynols with elemental sulfur (S8) or EtOCS2K in moderate-to-good yields. The method provides the base-free generation of a trisulfur radical anion (S3•–) and its addition to alkynes as an initiator. This research broadens the applications of S3•–in the synthesis of sulfur-containing heterocycles.