The diastereoselective nucleophilic (phenylsulfonyl)difluoromethylation and (phenylsulfonyl)monofluoromethylationof α-amino N-tert-butanesulfinimines (3) by using PhSO2CF2H and PhSO2CH2F reagents gave products 4 or 5 in highyields (73−99%) and with excellent diastereoselectivity (drup to >99:1). After subsequent reductive desulfonylation andacid-catalyzed alcoholysis, compounds 4 and 5 could bereadily transformed to chiral α-difluoromethylated or α-monofluoromethylated ethylenediamines in good yields.