Access to the aziridine products above allows further derivatization. For example, heterocyclic vicinal diamines are also relatively rare chemotypes. However, these can be prepared by treatment of the heterocyclic aziridines with, for example, a cyclic amine in the presence of catalytic TFA giving 58-60 with high fidelity for SN2 at the benzylic stereocenter (Scheme 3).