title: [5 + 2] Cycloaddition reaction of 2-vinylaziridines and sulfonyl isocyanates. Synthesis of seven-membered cyclic ureas.
abstract: The [5 + 2] cycloaddition reaction of 2-vinylaziridines with sulfonyl isocyanates proceeded smoothly under mild conditions, and various cyclic ureas were isolated in high yields. The remarkable solvent effect on the reaction was observed, and the preferential formation of the seven-membered ring occurred when the reaction was carried out in CH(2)Cl(2). The scope and limitation were studied, and the mechanism of this reaction was discussed. This study provides a new and simple method for the synthesis of seven-membered cyclic ureas.
authors.affiliation: Department of Chemistry, Faculty of Science, Tokyo University of Science, Kagurazaka, Shinjuku, Tokyo 162-8601, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Kanno
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yamanoi
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Koya
authors.forename: Isao
authors.initials: I
authors.lastname: Azumaya
authors.forename: Hyuma
authors.initials: H
authors.lastname: Masu
authors.forename: Ryu
authors.initials: R
authors.lastname: Yamasaki
authors.forename: Shinichi
authors.initials: S
authors.lastname: Saito
mesh_terms: D001386:Azides / Q000737:chemistry*; D003500:Cyclization; D017953:Isocyanates / Q000737:chemistry*; D015394:Molecular Structure; D014508:Urea / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001386:Azides; D017953:Isocyanates; D014508:Urea