Synthesis of a New Polyfluorinated Vinylogue of Tetrathiafulvalene through 1,3‐Dipolar Cycloaddition of Ethyl β‐Bromoperfluorodithiocrotonate with Dimethyl Acetylenedicarboxylate

Abstract

The ethyl ester of beta-bromoperfluorodithiocrotonic acid reacts with dimethyl acetylenedicarboxylate to give 1,4-difluoro-2,3-bis(trifluoromethyl)-but-2-ene-1,4-diylidene-2,2'-bis(4',5'-dicarbomethoxy-1',3'-dithiole) (4), a new type of vinylogue of tetrathiafulvalene. The thermal transformations of this compound lead, depending on the temperature, to the formation of the cyclization products: 11,14-difluoro-2,3,8,9-tetra(carbomethoxy)-12,13-bis(trifluoromethyl)-1,4,7,10-tetrathiadispiro[4.0.4.4]tetradeca-2,8,11,13-tetraene (8) or 5,8-difluoro-6,7-bis(trifluoromethyl)-2,3-bis(carboxymethyl)-1,4-benzodithiine (11).

Highly Functionalized Tetrathiafulvalenes: Riding along the Synthetic Trail from Electrophilic Alkynes

“…195 Noteworthy, a bis spiro analogue has been recently described arising through a different process from the thermal transformation of a fluorinated vinylog of TTF. 196 Since the importance of the purity of π-donors in the electrocrystallization experiments is well established, 193 this internal cyclization during the purification procedure (acid-mediated cyclization) or the electrooxidation process produced the spiro compound in sufficient quantity to have a spoiling effect on the quality of electrogenerated salts.…”

Cycloaddition reactions of polyfluoroalkylthioncarboxylic acid derivatives with dimethyl acetylenedicarboxylate (DMAD)

“…Recently, we have shown [6] that b-bromoperfluorodithiocrotonate (1) reacts with DMAD to give a new type of vinylogue of tetrathiafulvalene (2) (Scheme 2).…”