title: Catalytic asymmetric synthesis of 3,3'-diaryloxindoles as triarylmethanes with a chiral all-carbon quaternary center: phase-transfer-catalyzed S(N)Ar reaction.
abstract: Catalytic asymmetric synthesis of unsymmetrical triarylmethanes with a chiral all-carbon quaternary center was achieved by using a chiral bifunctional quaternary phosphonium bromide catalyst in the S(N)Ar reaction of 3-aryloxindoles under phase-transfer conditions. The presence of a urea moiety in the chiral phase-transfer catalyst was important for obtaining high enantioselectivity in this reaction.
authors.affiliation: Laboratory of Synthetic Organic Chemistry and Special Laboratory of Organocatalytic Chemistry, Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502 (Japan).
authors.forename: Seiji
authors.initials: S
authors.lastname: Shirakawa
authors.forename: Kenta
authors.initials: K
authors.lastname: Koga
authors.forename: Takashi
authors.initials: T
authors.lastname: Tokuda
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Keiji
authors.initials: K
authors.lastname: Maruoka
mesh_terms: D002384:Catalysis; D015394:Molecular Structure; D009282:Naphthalenesulfonates / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D009282:Naphthalenesulfonates; C016768:naphthosultone
keywords: arylation; asymmetric catalysis; organocatalysis; phase-transfer catalysis; synthetic methods