Ligand-controlled gold-catalyzed cycloisomerization of 1,n-enyne esters toward synthesis of dihydronaphthalene

We describe herein a gold-catalyzed rearrangement of propargyl esters followed by allene-ene cyclization to afford substituted bicyclic [4.4.0] dihydronaphthalene compounds. This method is also applied to vinylethers and vinylamines of 1,7-enyne esters to form dihydroquinoline and dihydrobenzopyran structures. The basis of this transformation is the ligand-controlled preferential activation of the alkene over the allene, affording the desired aromatic bicyclic structures in moderate to excellent yields.