title: The Cycloaddition of the Benzimidazolium Ylides with Alkynes: New Mechanistic Insights.
abstract: New insights concerning the reaction mechanism in the cycloaddition reaction of benzimidazolium ylides to activated alkynes are presented. The proposed pathway leading both to 2-(1H-pyrrol-1-yl)anilines and to pyrrolo[1,2-a]quinoxalin-4(5H)-ones involves an opening of the imidazole ring from the cycloaddition product, followed by a nucleophilic attack of the aminic nitrogen to a proximal carbonyl group and the elimination of a leaving group. The mechanistic considerations are fully supported by experimental data, including the XRD resolved structure of the key reaction intermediate.
authors.affiliation: Department of Chemistry, Alexandru Ioan Cuza University of Iasi, Iasi, Romania.
authors.forename: Costel
authors.initials: C
authors.lastname: Moldoveanu
authors.affiliation: Department of Chemistry, Alexandru Ioan Cuza University of Iasi, Iasi, Romania.
authors.forename: Gheorghita
authors.initials: G
authors.lastname: Zbancioc
authors.affiliation: Department of Chemistry, Alexandru Ioan Cuza University of Iasi, Iasi, Romania.
authors.forename: Dorina
authors.initials: D
authors.lastname: Mantu
authors.affiliation: Department of Chemistry, Alexandru Ioan Cuza University of Iasi, Iasi, Romania.
authors.forename: Dan
authors.initials: D
authors.lastname: Maftei
authors.affiliation: Department of Chemistry, Alexandru Ioan Cuza University of Iasi, Iasi, Romania.
authors.forename: Ionel
authors.initials: I
authors.lastname: Mangalagiu
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D000814:Aniline Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D061565:Cycloaddition Reaction; D008958:Models, Molecular; D015394:Molecular Structure; D011810:Quinoxalines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000480:Alkynes; D000814:Aniline Compounds; D011810:Quinoxalines