Synthesis of gem-difluoromethylenated biflavonoid via the Suzuki coupling reaction

Article abstract of DOI:10.1016/j.tetlet.2004.08.180

gem-Difluoromethylenated biflavonoid 1 was synthesized via the Suzuki coupling reaction. The key intermediate 6-iodonated flavone 4 was regioselectively synthesized by the use of AgOAc/I₂ under mild conditions without handling of a strongly toxic reagent. The key step was the formation of a flavone 3′-boronate 3 using a palladium-catalyzed exchange of the corresponding 3′-iodonated flavone with a diboron reagent.