title: Aqueous synthesis of 1-H-2-substituted benzimidazoles via transition-metal-free intramolecular amination of aryl iodides.
abstract: A straightforward method has been developed for the synthesis of the benzimidazole ring system through a carbon-nitrogen cross-coupling reaction. In the presence of 2.0 equiv. of K(2)CO(3) in water at 100 &#176;C for 30 h, the intramolecular cyclization of N-(2-iodoaryl)benzamidine provides benzimidazole derivatives in moderate to high yields. Remarkably, the procedure occurs exclusively in water and doesn&#8217;t require the use of any additional reagent/catalyst, rendering the methodology highly valuable from both environmental and economical points of view.
authors.affiliation: Department of Chemistry and Chemical Engineering, College of Science, Northeast Forestry University, Harbin, China.
authors.forename: Chunxia
authors.initials: C
authors.lastname: Chen
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Jingwei
authors.initials: J
authors.lastname: Tao
authors.forename: Jinsong
authors.initials: J
authors.lastname: Peng
mesh_terms: D000586:Amination; D001562:Benzimidazoles / Q000138:chemical synthesis*; D002254:Carbonates / Q000737:chemistry; D003500:Cyclization; D055772:Green Chemistry Technology; D007454:Iodides / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry; D012996:Solutions; D012997:Solvents / Q000737:chemistry; D028561:Transition Elements / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D001562:Benzimidazoles; D002254:Carbonates; D007454:Iodides; D012996:Solutions; D012997:Solvents; D028561:Transition Elements; D014867:Water; C037593:potassium carbonate; D011188:Potassium