Catalytic diastereoselective sulfimidation of diaryl sulfides and application of chiral sulfimides to asymmetric allylic alkylation

The copper-catalyzed diastereoselective imidation of diaryl sulfides bearin g a chiral oxazolinyl moiety at the ortho-position with [N-(p-toluenesulfon yl) imino]phenyliodinane (TsN=IPh) or Chloramine-T trihydrate [TsN(Cl)Na.3H (2)O] was successfully carried out to give the corresponding optically acti ve 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.3H(2)O in acetonitrile in the presence of 10 mol% Cu(O Tf)(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 i nto the corresponding optically active sulfimides in high yields without lo ss of diastereoselectivity. These novel optically active sulfimides and N-t osylsulfimides work as efficient chiral ligands for palladium (II)-catalyze d allylic alkylation of 1,3-diphenyl-3-acetoxy-1-propene with dimethyl malo nate to give the corresponding alkylation product quantitatively and with a high stereoselectivity (up to 90% ee). (C) 2000 Wiley-Liss, Inc.