title: Catalytic diastereoselective sulfimidation of diaryl sulfides and application of chiral sulfimides to asymmetric allylic alkylation.
abstract: The copper-catalyzed diastereoselective imidation of diaryl sulfides bearing a chiral oxazolinyl moiety at the ortho-position with [N-(p-toluenesulfonyl) imino]phenyliodinane (TsN=IPh) or Chloramine-T trihydrate [TsN(Cl)Na.3H2O] was successfully carried out to give the corresponding optically active N-tosylsulfimides in good yields. For example, the imidation of diphenyl sulfide bearing a methoxymethyl moiety at the 4-position of the oxazoline ring with TsN(Cl)Na.3H2O in acetonitrile in the presence of 10 mol% Cu(OTf)2 at 25 degrees C for 24 h affords the corresponding optically active N-tosylsulfimide in 52% isolated yield with a high diastereoselectivity of 99%. Hydrolysis of the optically active N-p-tosylsulfimides converts them into the corresponding optically active sulfimides in high yields without loss of diastereoselectivity. These novel optically active sulfimides and N-tosylsulfimides work as efficient chiral ligands for palladium(II)-catalyzed allylic alkylation of 1, 3-diphenyl-3-acetoxy-1-propene with dimethyl malonate to give the corresponding alkylation product quantitatively and with a high stereoselectivity (up to 90% ee).
authors.affiliation: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Takada
authors.forename: M
authors.initials: M
authors.lastname: Oda
authors.forename: A
authors.initials: A
authors.lastname: Oyamada
authors.forename: K
authors.initials: K
authors.lastname: Ohe
authors.forename: S
authors.initials: S
authors.lastname: Uemura