Vilsmeier–Haack Type Formylation on 6-Aryl-1,4-dithiafulvenes and Syntheses of Novel Extended Tetrathiafulvalene Donors
Received: 30 October 2015
Accepted after revision: 14 December 2015
11 January 2016 (eFirst)
The Vilsmeier–Haack type formylations on various 6-aryl-1,4-dithiafulvenes were examined. The furyl derivatives on treatment with an excess of POCl3 in DMF at room temperature mainly afforded dialdehydes substituted at the 6-position and the furan ring, while the thienyl derivatives and the phenyl derivatives mainly gave monoformylated derivatives substituted at the 6-position. The obtained mono- and dialdehydes were converted into monoaryl-substituted 2,2′-ethanediylidene-bis(1,3-dithiole) derivatives and heteroaromatic ring-inserted dendralene derivatives with triple 1,3-dithiol-2-ylidenes and their TTF-fused analogues. Electrochemical properties of the new π-electron donors were also investigated by cyclic voltammetry.