Mesoions as Versatile Intermediates in Tetrathiafulvalene Synthesis

Article abstract of DOI:10.1021/jo00019a041

Fourteen new alkylthio-substituted tetrathiafulvalene (TTF) donors have been prepared via the mesoionic 2-(N,N-dialkylamino)-5-methyl-1,3-dithiolium-4-thiolates 4.By S-alkylation with alkyl halogenides and alkyl dihalogenides, 4 was transformed into a variety of mono- and bis-1,3-dithiolium salts 5.Coupling of 5 with the anion of 4,5-dimethyl-2H-1,3-dithiole-2-phosphonate ester 6 yielded a series of bis(tetrathiafulvalenes) 2 and (alkylthio)tetrathiafulvalenes 3.By conventional methods, 5 was coupled to bis(alkylthio)tetrathiafulvalenes.The synthesis of 4 was improved.An N,N-dialkyldithiocarbamate salt was allowed to react with a 2-halo carboxylic acid to yield a 1-(carboxyalkyl)-N,N-dialkyldithiocarbamate ester 10, which was then transformed into 4.The electrochemistry of the new TTFs is reported.