Gold-Catalyzed Tandem Cyclizations of 1,6-Diynes Triggered by Internal N- and O-Nucleophiles

Investigations on gold-catalyzed tandem cyclization reactions of 1,6-diynes, tethered to nucleophilic functionalities such as amine, carboxylic acid, amide, and sulfonamide, are reported. The ability of such substrates to undergo tandem cyclization, triggered by internal nucleophiles, has been examined. Depending on the substrate, the catalytic system, and reaction conditions, different regioisomers of monocyclic and bridged bicyclic products were obtained.