Ruthenium(v) terminal arylimido corroles: isolation, spectroscopic characterization and reactivity

Abstract

Terminal Ru(V)–imido species are thought to be as reactive to group transfer reactions as their Ru(V)–oxo homologues, but are less studied. With the electron-rich corrole ligand, relatively stable and isolable Ru(V)–arylimido complexes [Ru(^tBu–Cor)(NAr)] (H₃(^tBu–Cor) = 5,15-diphenyl-10-(p-tert-butylphenyl)corrole, Ar = 2,4,6-Me₃C₆H₂ (Mes), 2,6-(ⁱPr)₂C₆H₃ (Dipp), 2,4,6-(ⁱPr)₃C₆H₂ (Tipp), and 3,5-(CF₃)₂C₆H₃ (BTF)) can be prepared from [Ru(^tBu–Cor)]₂ under strongly reducing conditions. This type of Ru(V)–monoarylimido corrole complex with S = ½ was characterized by high-resolution ESI mass spectrometry, X-band EPR, resonance Raman spectroscopy, magnetic susceptibility, and elemental analysis, together with computational studies. Under heating/light irradiation (xenon lamp) conditions, the complexes [Ru(^tBu–Cor)(NAr)] (Ar = Mes, BTF) could undergo aziridination of styrenes and amination of benzylic C(sp³)–H bonds with up to 90% product yields.