Symmetric ethenyldithiophenes are important intermediates for synthesis of photochromic materials and organic conductors. When acetonitrile is used as a solvent, 3- methylthiophenylphosphonium salts form symmetric ethenyldithiophenes in the presence of a strong base (eg, NaH, t BuOK) in moderate to high yields. This homocoupling reaction is faster than a Wittig reaction with aromatic ketones in acetonitrile. Our study shows that the ...
