Redox-Divergent Construction of (Dihydro)thiophenes with DMSO

Thiophene-based rings are one of the most widely used building blocks for the synthesis of sulfur-containing molecules. Inspired by the redox diversity of these features in nature, we demonstrate herein a redox-divergent construction of dihydrothiophenes, thiophenes, and bromothiophenes from the respective readily available allylic alcohols, dimethyl sulfoxide (DMSO), and HBr. The redox-divergent selectivity could be manipulated mainly by controlling the dosage of DMSO and HBr. Mechanistic studies suggest that DMSO simultaneously acts as an oxidant and a sulfur donor. The synthetic potentials of the products as platform molecules were also demonstrated by various derivatizations, including the preparation of bioactive and functional molecules.

Automated summary

This study demonstrates a redox-divergent construction of dihydrothiophenes, thiophenes, and bromothiophenes using allylic alcohols, DMSO, and HBr. The selectivity of the reaction can be manipulated by controlling the dosage of DMSO and HBr. The products show synthetic potentials as platform molecules for the preparation of various bioactive and functional molecules.