title: The conformational bias of aryl, arylsulfonyl geminally substituted tertiary carbon centers: applications in substrate-based stereocontrol.
abstract: Intramolecular nitrile oxide-olefin cycloaddition to form hexahydrobenzisoxazole 14, which engenders a phenylsulfonyl, 2,5-difluorophenyl geminally substituted carbon substructure, proceeds with up to 99% ds. A rationalization of the high level of substrate-based stereo-induction observed in this and related ketone and acrylonitrile metallohydride reductions, supported by single crystal X-ray crystallography, is presented.
authors.affiliation: Department of Process Research, Merck Sharp & Dohme Research Laboratories, Hoddesdon, Hertfordshire, UK. jeremy_scott@merck.com
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Scott
authors.forename: Peter R
authors.initials: PR
authors.lastname: Mullens
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Brewer
authors.forename: Karel M J
authors.initials: KM
authors.lastname: Brands
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Chilenski
authors.forename: Antony J
authors.initials: AJ
authors.lastname: Davies
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Gibb
authors.forename: David R
authors.initials: DR
authors.lastname: Lieberman
authors.forename: Steven F
authors.initials: SF
authors.lastname: Oliver
authors.forename: Ulf-H
authors.initials: UH
authors.lastname: Dolling
mesh_terms: D000475:Alkenes / Q000737:chemistry; D018360:Crystallography, X-Ray; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D008968:Molecular Conformation; D013450:Sulfones / Q000737:chemistry
chemical_list: D000475:Alkenes; D006841:Hydrocarbons, Aromatic; D013450:Sulfones