Regiocontrolled Synthesis of Polysubstituted Pyrroles Starting from Terminal Alkynes, Sulfonyl Azides, and Allenes

1-Sulfonyl-1,2,3-triazoles, readily prepared from terminal alkynes and sulfonyl azides, react with allenes in the presence of a nickel(0) catalyst to produce the corresponding isopyrroles. The initially produced isopyrroles are further converted to a wide range of polysubstituted pyrroles through double bond transposition and Alder-ene reactions.