Ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene in the presence of aryllithium reagents

In this paper, the ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene with aryllithium in THF at low temperature to generate 2'-arylthio-3,3'-bithiophene-2-carbaldehydes is studied. Nine examples are explored and all the products are characterized by 1H NMR, 13C NMR and HRMS. The relative relationship between the structures of aryl groups and the efficiency of ring-opening reactions are discussed.