title: Catalytic enantioselective carboannulation with allylsilanes.
abstract: The first catalytic asymmetric carboannulation with allylsilanes is presented. The enantioselective [3+2] annulation is catalyzed using a scandium(III)/indapybox complex with tetrakis-[3,5-bis(trifluoromethyl)phenyl]-borate (BArF) to enhance catalytic activity and control stereoselectivity. Functionalized cyclopentanes containing a quaternary carbon center are derived from alkylidene oxindole, coumarin, and malonate substrates with high stereoselectivity. The enantioselective 1,4-conjugate addition and enantioselective lactone formation (by trapping of the β-silyl carbocation) is also described.
authors.affiliation: Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616 (USA) http://chemgroups.ucdavis.edu/∼franz/
authors.forename: Nicolas R
authors.initials: NR
authors.lastname: Ball-Jones
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Badillo
authors.forename: Ngon T
authors.initials: NT
authors.lastname: Tran
authors.forename: Annaliese K
authors.initials: AK
authors.lastname: Franz
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis*; D001881:Borates / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D003517:Cyclopentanes / Q000737:chemistry; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis; D008958:Models, Molecular; D008968:Molecular Conformation; D012538:Scandium / Q000737:chemistry; D012821:Silanes / Q000138:chemical synthesis*; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D001881:Borates; D003517:Cyclopentanes; D006845:Hydrocarbons, Fluorinated; D007783:Lactones; D012821:Silanes; C511847:allylsilane; C000597414:tetrakis(3,5-bis(trifluoromethyl)phenyl)borate; D012538:Scandium
keywords: allylic compounds; asymmetric catalysis; conjugate addition; cyclization; scandium