title: Catalytic [3 + 2] Cycloaddition through Ring Cleavage of Simple Cyclopropanes with Isocyanates.
abstract: The catalytic synthesis of γ-butyrolactams was established via [3 + 2]-cycloaddition of cyclopropanes with isocyanates. An organotin iodide ate complex, MgBr(+)[Bu2SnBrI2](-), was employed as an effective catalyst. Simple cyclopropanes that lack aryl or vinyl substituents were useful precursors. Even acyl cyclopropanes were applicable. The hybrid characteristics of a tin complex, acidic MgBr(+) with nucleophilic tin iodide, was responsible for the catalytic reaction.
authors.affiliation: Research Center for Environmental Preservation, Osaka University, 2-4 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Tsunoi
authors.affiliation: Research Center for Environmental Preservation, Osaka University, 2-4 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Maruoka
authors.affiliation: Research Center for Environmental Preservation, Osaka University, 2-4 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Itaru
authors.initials: I
authors.lastname: Suzuki
authors.affiliation: Research Center for Environmental Preservation, Osaka University, 2-4 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Ikuya
authors.initials: I
authors.lastname: Shibata
mesh_terms: D001965:Bromides / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D061565:Cycloaddition Reaction; D003521:Cyclopropanes / Q000737:chemistry*; D017953:Isocyanates / Q000737:chemistry*; D007769:Lactams / Q000138:chemical synthesis* / Q000737:chemistry; D017616:Magnesium Compounds / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D001965:Bromides; D003521:Cyclopropanes; D017953:Isocyanates; D007769:Lactams; D017616:Magnesium Compounds; C586611:magnesium bromide