Abstract Vinyl aziridines are versatile starting materials toward ring-expansion transformations. Such processes widely used to give various medium or larger N-heterocycles of synthetic interest. This letter describes a copper-catalyzed ring expansion vinyl 3-pyrrolines by using Cu(I) salt [(CuOTf)2·toluene Cu(MeCN)4·PF6]. In particular, this transformation occurs under mild conditions (THF, rt).