New stable dication of 1,3,4,6-tetrakis(isopropylthio)-2λ4,δ2-thieno[3,4-c]thiophene generated by its oxidation using nitrosonium tetrafluoroborate

Abstract

The oxidation of 1,3,4,6-tetrakis(isopropylthio)-2λ⁴,δ²-thieno[3,4-c]thiophene 1 by NOBF₄(2 equiv.) gives the dication 2, which reacts with H₂O, MeOH and aniline to give the thiophene derivatives 3–5 by fission of the C–S bond of the thieno[3,4-c]thiophene ring; 2 also reacts with 1,2-dimercaptobenzene and NaBH₄ to give the adducts 6 and 7 respectively.