Scandium triflate-catalyzed 1,3-dipolar cycloaddition of aziridines with alkenes

Phenyl aziridines undergo 1,3-dipolar cycloaddition efficiently with olefins such as cyclic enol ethers and allyltrimethylsilane in the presence of a catalytic amount of Sc(OTf)3 at ambient temperature to afford the corresponding pyrrolidine derivatives in high yields with high regioselectivity.