An efficient cyclocarboamination reaction of nonactivated alkynes with aziridines, catalyzed by Lewis or Bronsted acids, to form 2,3-dihydropyrroles through a format [3+2] cycloaddition, is described. The reaction provides a wide range of polysubstituted dihydropyrroles in a highly regioselective manner, is scalable, proceeds under mild reaction conditions, and uses low catalyst loadings.