Gold(I)‐Catalyzed Synthesis of Benzofurans from Tetrahydropyranyl (THP) Ethers of <i>o</i>‐Alkynylphenols

The activation of π-systems in alkenes and alkynes by homogeneous gold catalysts is a powerful tool for the synthesis of benzo-fused heterocycles. Decades of development in the area of gold catalysis have brought an array of new catalysts and with them the discovery of new modes of carbophilic activation of π-systems in alkenes and alkynes, and investigations of previously unknown mechanistic pathways. In alignment with these efforts, we report a cyclization of tetrahydropyranyl ethers of 2-alkynylphenols to form benzofurans catalyzed by a gold(I)-NHC complex. The reaction proceeds efficiently at very low catalyst loadings, and the products form in good yields.