Nickel- and Palladium-Catalyzed Cross-Coupling Reaction of Polyfluorinated Arenes and Alkenes with Grignard Reagents

The cross-coupling reaction of fluorobenzene with an aryl Grignard reagent has been reinvestigated which revealed that the reaction readily proceeds under ordinary conditions using a catalytic amount of NiCl2(dppp) even at room temperature. The use of nickel catalysts and Grignard reagent is essential for the activation of the carbon-fluorine bond. The palladium catalyst is also effective for the 1,2-difluorobenzene and trifluorobenzenes to selectively produce the corresponding mono-coupled products while the nickel-based catalyst system affords a mixture of the mono-coupled product and di- or tri-coupled product.