title: Asymmetric cyclopropanation of β,γ-unsaturated α-ketoesters with stabilized sulfur ylides catalyzed by C2-symmetric ureas.
abstract: A novel organocatalytic asymmetric cyclopropanation of β,γ-unsaturated α-ketoesters with stabilized sulfur ylides using C(2)-symmetric urea as a hydrogen-bond catalyst has been described. This reaction allows an efficient access to 1,2,3-trisubstituted cyclopropane derivatives in moderate to good yields with up to 16:1 dr and 90:10 er under mild reaction conditions. The mechanism study proved that the high stereoinduction originated from the cooperative effect of the hydrogen-bond catalyst.
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, Hubei 430079, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Cheng
authors.forename: Jing
authors.initials: J
authors.lastname: An
authors.forename: Liang-Qiu
authors.initials: LQ
authors.lastname: Lu
authors.forename: Lan
authors.initials: L
authors.lastname: Luo
authors.forename: Zheng-Yi
authors.initials: ZY
authors.lastname: Wang
authors.forename: Jia-Rong
authors.initials: JR
authors.lastname: Chen
authors.forename: Wen-Jing
authors.initials: WJ
authors.lastname: Xiao
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D003500:Cyclization; D003521:Cyclopropanes / Q000737:chemistry*; D004952:Esters; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013237:Stereoisomerism; D013455:Sulfur / Q000737:chemistry*; D014508:Urea / Q000737:chemistry*
chemical_list: D003521:Cyclopropanes; D004952:Esters; D007659:Ketones; D013455:Sulfur; D014508:Urea; C030797:cyclopropane