title: Chiral bisguanidine-catalyzed inverse-electron-demand hetero-Diels-Alder reaction of chalcones with azlactones.
abstract: A new type of C(2)-symmetric chiral bisguanidine was designed as a highly efficient catalyst in the inverse-electron-demand hetero-Diels-Alder reaction of chalcones with azlactones for the first time. A wide variety of gamma,delta-unsaturated delta-lactone derivatives with alpha-quaternary-beta-tertiary stereocenters were obtained in high yields (up to 88%) with excellent enantioselectivities (up to 99% ee). Hydrogen bonds were considered to be crucial for the activation and stereoinduction of the reaction. In all cases, the major was HDA adducts, which were obtained as a single diastereomer along with little amount of Michael addition products.
authors.affiliation: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, PR China.
authors.forename: Shunxi
authors.initials: S
authors.lastname: Dong
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Liu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Chen
authors.forename: Fang
authors.initials: F
authors.lastname: Mei
authors.forename: Yulong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Gao
authors.forename: Lili
authors.initials: L
authors.lastname: Lin
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Feng
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D002384:Catalysis; D047188:Chalcones / Q000737:chemistry*; D004583:Electrons; D006146:Guanidines / Q000737:chemistry*; D006860:Hydrogen Bonding; D007783:Lactones / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D001372:Aza Compounds; D047188:Chalcones; D006146:Guanidines; D007783:Lactones