An eco-friendly sulfide transfer protocol is explored under a reductive Pd-catalyzed, Ni-mediated condition. Both experimental and theoretical results support the sulfide transfer over the aryl transfer. Late-functionalization of drugs and semiconducting materials highlight the importance of the method.
Regioselective Oligomerization of 3-(Alkylsulfanyl)thiophenes with Ferric Chloride
作者:Giovanna Barbarella、Massimo Zambianchi、Rosanna Di Toro、Martino Colonna、Dario Iarossi、Francesca Goldoni、Alessandro Bongini
DOI:10.1021/jo960982j
日期:1996.11.15
The action of FeCl3 on 3-(alkylsulfanyl)thiophenes (3-(alkylthio)thiophenes) leads to the one-step formation of regioregular alpha-conjugated oligothiophenes, from trimer to octamer, depending on the solvent used and on the length of the alkyl chain. The regiochemistry of these oligomers is characterized by one inner head-to-head linkage between adjacent rings and by a variable number of lateral head-to-tail junctions. The reaction of ferric chloride with the head-to-head and head-to-tail bis(methylsulfanyl)-2,2'-bithiophenes gives the corresponding tetramers, while the reaction with the tail-to-tail counterpart affords a high molecular weight insoluble material. With the aid of theoretical calculations, these results are interpreted on the basis of the joint effects of the orienting power of the substituents and of the stability of the radical cations formed during the oxidative process.