Gold‐Catalyzed Carbocyclization of Phenols with a Terminal Alkyne <i>via</i> an Intramolecular <i>ipso</i>‐Friedel–Crafts Alkenylation

Abstract

Abstract We have developed a novel synthetic method to furnish spiro[4.5]cyclohexadienones using an gold‐catalyzed carbocyclization of phenols with a terminal alkyne via an intramolecular ipso ‐Friedel–Crafts alkenylation. Using 2–5 mol% of gold catalyst, 1 equiv. of methanesulfonic acid, and 1 equiv. of 2,6‐di‐ tert ‐butylpyridine, a variety of spiro[4.5]cyclohexadienone derivatives with an exo ‐cyclic olefin unit was obtained in good to excellent yields. The divergent synthesis of dihydronaphthalene derivatives was also examined based on the newly developed gold catalysis. magnified image