Gold-Catalyzed Domino Aminocyclization/1,3-Sulfonyl Migration of N‑Substituted N‑Sulfonyl-aminobut-3-yn-2-ols to 1‑Substituted 3‑Sulfonyl‑1H‑pyrroles

A method to prepare 1-substituted 3-sulfonyl-1H-pyrroles efficiently that relies on the gold­(I)-catalyzed cycloisomerization of N-substituted N-sulfonyl-aminobut-3-yn-2-ols is described. The method was shown to be applicable to a broad range of 1,7-enyne alcohols containing electron-withdrawing, electron-donating, and sterically demanding substrate combinations. The mechanism is suggested to involve activation of the propargylic alcohol by the Au­(I) catalyst, which causes the intramolecular nucleophilic addition of the sulfonamide unit to the alkyne moiety. The resulting nitrogen-containing heterocyclic intermediate undergoes dehydration and deaurative 1,3-sulfonyl migration, a process that remains rare in gold catalysis, to give the aromatic nitrogen-containing product.