Palladium-Catalyzed Double ipso-Defluoroetherification of Allylic gem-Difluorides with Phenols or Alcohols.

Significant progress has been made in the synthesis of diverse ketals through a palladium-catalyzed reaction involving allylic gem-difluorides and various phenols or alcohols. This methodology facilitates double ipso-defluoroetherification of allylic gem-difluorides, resulting in high product yields with excellent regioselectivity. The reactions were conducted under mild conditions and exhibited outstanding tolerance to a wide range of functional groups. Notably, this approach overcomes the traditional limitation of palladium-catalyzed processes, where nucleophiles typically target the common C-1 position of allylic gem-difluorides, enabling selective functionalization at the rare C-3 position instead.