title: A convenient synthesis of symmetric 1,2-diarylethenes from arylmethyl phosphonium salts.
abstract: 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 (e.g., 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 presence of polar aprotic solvents promotes the homocoupling reaction.
authors.affiliation: Department of Chemistry, University of North Dakota, Grand Forks, ND 58202-9024, USA.
authors.forename: Julius N
authors.initials: JN
authors.lastname: Ngwendson
authors.forename: Walters N
authors.initials: WN
authors.lastname: Atemnkeng
authors.forename: Cassandra M
authors.initials: CM
authors.lastname: Schultze
authors.forename: Anamitro
authors.initials: A
authors.lastname: Banerjee