title: Selective synthesis of eight-membered cyclic ureas by the [6 + 2] cycloaddition reaction of 2-vinylazetidines and electron-deficient isocyanates.
abstract: The [6 + 2] cycloaddition reaction of 2-vinylazetidines with electron-deficient isocyanates such as tosyl isocyanate proceeded smoothly in the absence of the catalyst at room temperature, and various cyclic ureas were isolated in good to high yields. Electron-deficient allenes also reacted with the 2-vinylazetidine, and the corresponding azocine derivatives were isolated.
authors.affiliation: Department of Chemistry, Faculty of Science, Tokyo University of Science, Kagurazaka, Shinjuku, Tokyo, Japan 162-8601.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Koya
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yamanoi
authors.forename: Ryu
authors.initials: R
authors.lastname: Yamasaki
authors.forename: Isao
authors.initials: I
authors.lastname: Azumaya
authors.forename: Hyuma
authors.initials: H
authors.lastname: Masu
authors.forename: Shinichi
authors.initials: S
authors.lastname: Saito
mesh_terms: D000466:Alkadienes / Q000737:chemistry; D001384:Azetidines / Q000737:chemistry*; D001392:Azocines / Q000138:chemical synthesis / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D017953:Isocyanates / Q000737:chemistry*; D015394:Molecular Structure; D013696:Temperature; D014105:Tosyl Compounds / Q000737:chemistry; D014508:Urea / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000466:Alkadienes; D001384:Azetidines; D001392:Azocines; D017953:Isocyanates; D014105:Tosyl Compounds; C025947:propadiene; D014508:Urea