title: Organocatalytic asymmetric synthesis of 3-chlorooxindoles bearing adjacent quaternary-tertiary centers.
abstract: A new methodology was developed for the synthesis of enantiomerically enriched 3,3-disubstituted 3-chlorooxindoles 3 via a Michael addition of 3-chloroxindoles to nitroolefins 2, catalyzed by chiral squaramide 10. Products with adjacent quaternary-tertiary centers were isolated in excellent yields (up to 99%), high diastereoselectivities (up to 11:1), and enantiomeric purities (up to 92%). This is the first example where 3-chloroxoindoles 1 have been used as nucleophiles in a highly stereoselective organocatalytic reaction.
authors.affiliation: Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
authors.forename: Artur
authors.initials: A
authors.lastname: Noole
authors.forename: Ivar
authors.initials: I
authors.lastname: Järving
authors.forename: Franz
authors.initials: F
authors.lastname: Werner
authors.forename: Margus
authors.initials: M
authors.lastname: Lopp
authors.forename: Andrei
authors.initials: A
authors.lastname: Malkov
authors.forename: Tõnis
authors.initials: T
authors.lastname: Kanger
mesh_terms: D002384:Catalysis; D006843:Hydrocarbons, Chlorinated / Q000138:chemical synthesis* / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D006843:Hydrocarbons, Chlorinated; D007211:Indoles