title: Characterization and Reactivity Studies of a Terminal Copper-Nitrene Species.
abstract: High-valent terminal copper-nitrene species have been postulated as key intermediates in copper-catalyzed aziridination and amination reactions. The high reactivity of these intermediates has prevented their characterization for decades, thereby making the mechanisms ambiguous. Very recently, the Lewis acid adduct of a copper-nitrene intermediate was trapped at -90 °C and shown to be active in various oxidation reactions. Herein, we describe for the first time the synthesis and spectroscopic characterization of a terminal copper(II)-nitrene radical species that is stable at room temperature in the absence of any Lewis acid. The azide derivative of a triazamacrocyclic ligand that had previously been utilized in the stabilization of aryl-CuIIIintermediates was employed as an ancillary ligand in the study. The terminal copper(II)-nitrene radical species is able to transfer a nitrene moiety to phosphines and abstract a hydrogen atom from weak C-H bonds, leading to the formation of oxidized products in modest yields.
authors.affiliation: Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus Montilivi, E, 17003, Girona, Catalonia, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Corona
authors.affiliation: Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus Montilivi, E, 17003, Girona, Catalonia, Spain.
authors.forename: Lídia
authors.initials: L
authors.lastname: Ribas
authors.affiliation: Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus Montilivi, E, 17003, Girona, Catalonia, Spain.
authors.forename: Mireia
authors.initials: M
authors.lastname: Rovira
authors.affiliation: Case Western Reserve University Center for Synchrotron Biosciences and Center for Proteomics and Bioinformatics, National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, 11973, USA.
authors.forename: Erik R
authors.initials: ER
authors.lastname: Farquhar
authors.affiliation: Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus Montilivi, E, 17003, Girona, Catalonia, Spain. xavi.ribas@udg.edu.
authors.forename: Xavi
authors.identifier: 0000-0002-2850-4409
authors.initials: X
authors.lastname: Ribas
authors.affiliation: Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor Strasse 2, 12489, Berlin, Germany. kallol.ray@chemie.hu-berlin.de.
authors.forename: Kallol
authors.initials: K
authors.lastname: Ray
authors.affiliation: Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus Montilivi, E, 17003, Girona, Catalonia, Spain. anna.company@udg.edu.
authors.forename: Anna
authors.identifier: 0000-0003-4845-4418
authors.initials: A
authors.lastname: Company
mesh_terms: D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007097:Imines / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011789:Quantum Theory
chemical_list: D007097:Imines; C017621:phenylnitrene; D003300:Copper
keywords: copper-nitrene species; density functional calculations; hydrogen atom abstraction; mass spectrometry; nitrene transfer