Reaction of 1-substituted benzimidazoles with acylacetylenes and water: ring-opening versus ring-expansion and isotopic effect of deuterium. Issue 19 (13th May 2015)

• Record Type: Journal Article
• Authors: Belyaeva, Kseniya V.; Andriyankova, Lyudmila V.; Nikitina, Lina P.; Bagryanskaya, Irina Yu.; Afonin, Andrei V.; Ushakov, Igor A.; Mal'kina, Anastasiya G.; Trofimov, Boris A.
• Is Part Of: Tetrahedron. Volume 71:Issue 19(2015)
• Page Start: 2891
• Page End: 2899
• Publication Date: 2015-05-13
• Subjects: Acylacetyles -- β-Aminovinyl ketones -- Benzodiazocinone -- Multicomponent reactions -- Zwitteriones; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2015.03.056
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: 1-Substituted benzimidazoles react with acylacetylenes and water (reflux in MeCN, 46–120 h) to stereoselectively give functionalized arylaminovinyl ketones, products of the imidazole ring-opening, in up to 75% yield and benzodiazocinones, products of the imidazole ring-expansion, in up to 28% yield. With D2 O the yield of benzodiazocinone from 1-methylbenzimidazole and benzoylphenylacetylene is twice as much compared to the same reaction with H2 O, thus demonstrating the strong isotopic effect of deuterium. The reaction mechanism, which agrees with deuterium distribution in the products, is discussed. Graphical abstract: