Addition Reactions of Chloro- or Iodomethyllithium to Imines. Synthesis of Enantiopure Aziridines and β-Chloroamines

We report a novel, simple, and efficient synthesis of aziridines and 1-chloroalkan-2-amines by the reaction of imines derived from various aldehydes and p-toluenesulfonamide or benzenesulfonamide with iodo- or chloromethyllithium, respectively. Both halogenated anions were generated in situ by treatment of diiodo- or chloroiodomethane with methyllithium at −78 or 0 °C. The reaction of in situ generated iodo- or chloromethyllithium could also be performed from chiral 2-aminoaldimines to yield enantiopure aziridines or (2S,3S)-2,3-diamino-1-chloroalkanes with high stereoselectivity.