title: C-N Bond Formation from a Masked High-Valent Copper Complex Stabilized by Redox Non-Innocent Ligands.
abstract: The reactivity of a stable copper(II) complex bearing fully oxidized iminobenzoquinone redox ligands towards nucleophiles is described. In sharp contrast with its genuine low-valent counterpart bearing reduced ligands, this complex performs high-yielding C-N bond formations. Mechanistic studies suggest that this behavior could stem from a mechanism akin to reductive elimination occurring at the metal center but facilitated by the ligand: it is proposed that a masked high oxidation state of the metal can be stabilized as a lower copper(II) oxidation state by the redox ligands without forfeiting its ability to behave as a high-valent copper(III) center. These observations are substantiated by a combination of advanced EPR spectroscopy techniques with DFT studies. This work sheds light on the potential of redox ligands as promoters of unusual reactivities at metal centers and illustrates the concept of masked high-valent metallic species.
authors: Sorbonne Universités, UPMC, Université Paris 06, UMR CNRS 8232, Institut Parisien de Chimie Moléculaire, France.
authors: Jérémy
authors: J
authors: Jacquet
authors: Sorbonne Universités, UPMC, Université Paris 06, UMR CNRS 8232, Institut Parisien de Chimie Moléculaire, France.
authors: Pauline
authors: P
authors: Chaumont
authors: Sorbonne Universités, UPMC, Université Paris 06, UMR CNRS 8232, Institut Parisien de Chimie Moléculaire, France.
authors: Geoffrey
authors: G
authors: Gontard
authors: Aix Marseille Université, CNRS, Centrale Marseille, iSm2 UMR 7313, 13397, Marseille cedex 20, France.
authors: Maylis
authors: 0000-0002-9317-8005
authors: M
authors: Orio
authors: Laboratoire de Spectrochimie Infrarouge et Raman, Université des Sciences et Technologies de Lille, UMR CNRS 8516, 59655, Villeneuve O'Ascq Cedex, France.
authors: Hervé
authors: 0000-0002-7282-2703
authors: H
authors: Vezin
authors: Sorbonne Universités, UPMC, Université Paris 06, UMR CNRS 8232, Institut Parisien de Chimie Moléculaire, France.
authors: Sébastien
authors: S
authors: Blanchard
authors: Sorbonne Universités, UPMC, Université Paris 06, UMR CNRS 8232, Institut Parisien de Chimie Moléculaire, France. marine.desage-el_murr@upmc.fr.
authors: Marine
authors: 0000-0001-5017-4496
authors: M
authors: Desage-El Murr
authors: Sorbonne Universités, UPMC, Université Paris 06, UMR CNRS 8232, Institut Parisien de Chimie Moléculaire, France. louis.fensterbank@upmc.fr.
authors: Louis
authors: 0000-0003-0001-7120
authors: L
authors: Fensterbank
keywords: copper; density functional calculations; ligand effects; reaction mechanisms; redox chemistry