Elemental-Sulfur-Enabled Divergent Synthesis of Disulfides, Diselenides, and Polythiophenes from β-CF3-1,3-Enynes

Divergent synthesis for precise constructions of cyclic unsymmetrical diaryl disulfides or diselenides and polythiophenes from CF3-containing 1,3-enynes and S-8 was developed when the ortho group is F, Cl, Br, and NO2 on aromatic rings. Meanwhile, disulfides (diselenides) were also quickly constructed when the ortho group is H. These transformations undergo cascade thiophene construction/selective C3-position thiolation process, featuring simple operations, divergent synthesis, broad substrate scope, readily available starting materials, and valuable products. A novel plausible radical annulation process was proposed and validated by DFT calculations for the first time. A series of derivatizations about the thiophene (TBT) and disulfides were also well-represented.