One-pot protocol to functionalized benzopyrrolizidine catalyzed successively by Rh2(OAc)4 and Cu(OTf)2: a transition metal-Lewis acid catalysis relay.

4-N-Allylarylpropylamino-1-sulfonyl triazoles are converted to structurally unique benzopyrrolizidinyl sulfonamides in a one-pot operation. Intramolecular capture of rhodium carbene with arylamino nitrogen gives rise to the formation of an ammonium ylide immediate. A [2,3]- or [1,2]-rearrangement occurs to give a 2-allylpyrrolidinyl-2-carbimine intermediate which undergoes Cu(OTf)2 catalyzed aza-Friedel–Crafts cyclization to finish a highly functionalized tricyclic system decorated with a synthetically difficult quaternary carbon center, a sulfonamide group, and an allyl segment.