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Updated: Jul 20, 2026

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)
Published on: November 22, 2016
A convenient synthesis of symmetric 1,2-diarylethenes from arylmethyl phosphonium salts
Julius N Ngwendson1, Walters N Atemnkeng, Cassandra M Schultze
1Department of Chemistry, University of North Dakota, Grand Forks, ND 58202-9024, USA.
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.
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