Synthesis of α-Thiophene Oligomers via 1,3-Butadiynes

Article abstract of DOI:10.1021/jo00171a032

Individual oligomers possessing thiophenes linked by their 2- and 5-positions are conveniently prepared via 1,3-butadiynes.These can be prepared in good yield by the Glaser symmetrical coupling of thienylacetylenes.Following the cyclization of the 1,3-butadiyne unit into a thiophene with sodium sulfide, an oligomer possessing an odd number of thiophene rings is obtained.Oligomers with an even number of rings are accessible from unsymmetrical butadiynes obtained either by the Cadiot-Chodkiewicz procedure, utilizing an odd and an even precursor, or by an organoborane co upling procedure.