Catalyst-controlled divergent intermolecular cycloadditions of vinylaziridines with alkynes have been developed. By using [Rh(NBD)(2)]BF4 as the catalyst, a [3 + 2] cycloaddition reaction was achieved with broad substrate scope and high stereoselectivity under mild reaction.conditions. Moreover, the chirality of vinylaziridines can be completely transferred to the [3 + 2] cycloadducts. When the catalyst was changed to [Rh(eta(6)-C10H8) (COD)]SbF6, the alternative [S + 2] cycloadducts were selectively formed under otherwise identical conditions.