Asymmetric synthesis of trifluoromethylated aziridines from CF3-substituted N-tert-butanesulfinyl ketimines

A convenient and practical method for the asymmetric synthesis of trifluoromethylated aziridines was developed. The reactions of sulfur ylide with (S)-N-tert-butanesulfinyl ketimines gave trifluoromethylated aziridines 3 in moderate to excellent yields (45–93%) and good diastereoselectivities (86:14 to >99:1 dr). The synthetic application of these aziridines was examined through the acidic deprotection of the sulfinyl group and ring-opening reaction with dimethylsulfonium methylide to afford trifluoromethylated cyclopropylamine and α-trifluoromethylallylamine in 80% and 67% yields, respectively.