MOLTECH-Anjou, UMR CNRS 6200, University of Angers, Angers, France
Abstract:
Aromatization of 4‐cyano‐3‐oxotetrahydrothiophene by sulfuryl chloride gives the new building block 4‐cyano‐3‐pyrrolidylthiophene, which forms unsymmetrical regioregular oligothiophenes with a strict alternation of the donor and acceptor groups along the conjugated system. The self‐coupling reactions that form the oligomers are shown to proceed by a regioselective electrophilic aromatic substitution mechanism involving a stabilized Wheland intermediate.