Stereoselective synthesis of α-(dichloromethyl)-amines, α-(chloromethyl)amines, and α-chloro-aziridines

Protocols for the stereoselective synthesis of α-(dichloromethyl)amines, α-(chloromethyl)amines, and α-chloroaziridines are presented. Diastereoselective synthesis of α-(dichloromethyl)amines was achieved based on nucleophilic dichloromethylation of aromatic N-tert-butylsulfinyl aldimines with (dichloromethyl)trimethylsilane at a low reaction temperature. Slowly warming the reaction mixture up to room temperature gave α-chloro cis-aziridines. Additionally, with Bu3SnH as the reductant, α-(dichloromethyl)amines were readily obtained from easily accessible α-(trichloromethyl)amines via mono-dechlorination. Over-reduction was successfully suppressed. Subsequent radical mono-dechlorination of the α-(dichloromethyl)amines gave the corresponding α-(chloromethyl)amines in good to excellent yields.