title: Direct transition-metal-free intramolecular C-O bond formation: synthesis of benzoxazole derivatives.
abstract: A direct base-mediated intramolecular carbon-oxygen bond formation has been developed without a transition-metal catalyst. In the presence of 2.0 equiv of K(2)CO(3) in DMSO at 140 °C, the intramolecular cyclization of o-haloanilides affords benzoxazoles in high yields. A mechanism via an initial formation of a benzyne intermediate followed by nucleophilic addition to form the C-O bond has been proposed.
authors.affiliation: Department of Chemistry and Chemical Engineering, College of Science, Northeast Forestry University, Harbin 150040, P. R. China. jspeng1998@163.com
authors.forename: Jinsong
authors.initials: J
authors.lastname: Peng
authors.forename: Cuijuan
authors.initials: C
authors.lastname: Zong
authors.forename: Min
authors.initials: M
authors.lastname: Ye
authors.forename: Tonghui
authors.initials: T
authors.lastname: Chen
authors.forename: Dewei
authors.initials: D
authors.lastname: Gao
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Chunxia
authors.initials: C
authors.lastname: Chen
mesh_terms: D001583:Benzoxazoles / Q000138:chemical synthesis*; D002244:Carbon / Q000737:chemistry*; D015394:Molecular Structure; D010100:Oxygen / Q000737:chemistry*
chemical_list: D001583:Benzoxazoles; D002244:Carbon; D010100:Oxygen