Sodium Tetrathionate-Promoted Trisulfurative Annulation of 1,3-Diyne Diols toward Dithieno[3,2-b:2′,3′- d ]thiophenes

A sodium tetrathionate-promoted trisulfurative annulation of 1,3-diyne diols has been developed for the synthesis of polysubstituted dithieno[3,2-b:2′,3′-d]thiophenes (DTTs) in moderate to good yields. To the best of our knowledge, this represents the first use of sodium tetrathionate as a sulfur-centered radical precursor for the thioannulation of 1,3-diyne diols. This transformation combines dehydration with the formation of six C–S bonds in a sequential two-step protocol.