Gold-Catalyzed Dearomatization of 2-Naphthols with Alkynes.

The site-selective dearomatization of naphthols is realized in a straightforward manner through a gold(I)-catalyzed [3,3]-sigmatropic rearrangement/allene functionalization cascade sequence. The method employs readily available naphthylpropargyl ethers as starting materials. A range of densely functionalized dihydrofurylnaphthalen-2(1H)-ones are obtained in high yields (up to 98 %) and extremely mild reaction conditions (reagent grade solvent, air, 10 minute reaction time). A complete theoretical elucidation of the reaction machinery is also proposed, providing a rationale for important issues such as regio- and chemoselectivity.