Exploiting the trifluoroethyl group as a precatalyst ligand in nickel-catalyzed Suzuki-type alkylations

We report herein the exploitment of the partially fluorinated trifluoroethyl as precatalyst ligands in nickel-catalyzed Suzuki-type alkylation and fluoroalkylation coupling reactions. Compared with the [L(n)Ni(II)(aryl)(X)] precatalysts, the unique characters of bis-trifluoroethyl ligands imparted precatalyst [(bipy)Ni(CH(2)CF(3))(2)] with bench-top stability, good solubilities in organic media and interesting catalytic activities. Preliminary mechanistic studies reveal that an eliminative extrusion of a vinylidene difluoride (VDF, CH(2)[double bond, length as m-dash]CF(2)) mask from [(bipy)Ni(CH(2)CF(3))(2)] is a critical step for the initiation of a catalytic reaction.