Catalytic N-N Coupling of Aryl Azides To Yield Azoarenes via Trigonal Bipyramid Iron-Nitrene Intermediates

摘要

Organoazides (N_3R) are desirable reagents for nitrene transfer reactions. Generally, organoazides interact with transition metal catalysts to form transient M-N_3R adduct species that in many cases subsequently extrude N_2 to yield metal-imidoitrene (MNR) complexes as the key reactive intermediates for substrate activation. Understanding the properties of metal-organoazide and metal-imido/ nitrene complexes is fundamentally important in this context. Several iron-imidoitrene intermediates that are unstable toward hydrogen atom abstraction and/or intramolecular ligand oxidation pathways have been proposed for various coordination geometries.