Bypassing the Nitrido Wall Using a Redox-Active Isocyanide: Nucleophilic Attack on CO by a Rhenium Nitride Complex

Reactive rhenium(III) nitride complexes could result from filling Re─N π* orbitals, but such complexes lie beyond the “nitrido wall” and are rare due to their instability. Here, we describe a method for bypassing the nitrido wall by incorporating a redox-active isocyanide supporting ligand, which accommodates two electrons as shown by crystallographic, spectroscopic, and computational studies. These electrons can be returned to the metal during its facile reaction with CO to form a cyanate complex, demonstrating the nucleophilic reactivity of the nitride. Thus, assistance by the isocyanide enables an N₂-derived rhenium nitride to engage in N─C bond forming reactivity.