Divergent Reactivity of a Dinuclear (NHC)Nickel(I) Catalyst versus Nickel(0) Enables Chemoselective Trifluoromethylselenolation

We herein showcase the ability of NHC‐coordinated dinuclear Ni(I)–Ni(I) complexes to override fundamental reactivity limits of mononuclear (NHC)Ni(0) catalysts in cross‐couplings. This is demonstrated with the development of a chemoselective trifluoromethylselenolation of aryl iodides catalyzed by a Ni(I) dimer. A novel SeCF(3)‐bridged Ni(I) dimer was isolated and shown to selectively react with Ar−I bonds. Our computational and experimental reactivity data suggest dinuclear Ni(I) catalysis to be operative. The corresponding Ni(0) species, on the other hand, suffers from preferred reaction with the product, ArSeCF(3), over productive cross‐coupling and is hence inactive.