An Intramolecular Reaction between Pyrroles and Alkynes Leads to Pyrrole Dearomatization under Cooperative Actions of a Gold Catalyst and Isoxazole Cocatalysts

The gold-catalyzed one-pot synthesis of 3<i>H</i>-benzo[<i>e</i>]isoindoles (<b>3</b>) from a mixture of isoxazole (<b>2</b>) and diynamides (<b>1</b>) is described. This tandem catalysis involves two separate steps: (i) initial synthesis of 2-(3-pyrrolyl)-1-alkynylbenzenes and (ii) a novel alkyne/pyrrole coupling reaction through pyrrole dearomatization. Our control experiments reveal the cooperative action of the gold catalyst and isoxazole cocatalyst to enable the novel alkyne/pyrrole coupling leading to a 1,2-acyl shift.