Palladium-Catalyzed Cascade Carbopalladation/Phenol Dearomatization Reaction: Construction of Diversely Functionalized Spirocarbocyclic Scaffolds.

A novel palladium-catalyzed cascade carbopalladation/phenol dearomatization reaction has been achieved. The process provides a variety of indolone-, dihydrobenzofuran-, dihydrobenzopyran- and hydroquinoline-containing spirofused molecules bearing two quaternary centers in moderate to good yields. The potential synthetic utility of this method is demonstrated by a gram-scale experiment and further transformations.