title: Dioxygenase-like reactivity of an isolable superoxo-nickel(II) complex.
abstract: Although O(2) activation by metals such as iron and copper has been a matter of intensive research in the last decades, this type of chemistry for nickel systems is still in its infancy. Moreover, studies regarding the oxidizing ability of the resulting "Ni(n)-O(2)" species towards exogenous substrates are scarce. In this work, we report on the reactivity of an isolable and thermally stable mononuclear superoxo-nickel compound [Ni(II)(beta-diketiminato)(O(2))] (1) towards different types of organic substrates. In addition, we have been able to prove that the beta-diketiminato ligand can undergo partial intramolecular oxidation due to close proximity between the isopropyl groups of the beta-diketiminato-aryl and the superoxo subunits. Compound 1 performs hydrogen-atom abstraction from O-H and N-H groups and most importantly it shows an unprecedented dioxygenase-like reactivity in the oxidation of 2,4,6-tri-tert-butylphenol. The latter reaction most likely occurs through the mediation of a putative [Ni(III)-oxo] intermediate, affording an unprecedented oxidation product of the phenol that incorporates two oxygen atoms from a single O(2) subunit. Results presented herein provide evidence of the striking oxidizing ability of dioxygen-nickel species and further support the viability to use such systems as oxidation catalysts analogous to its heavy metal congener, palladium.
authors.affiliation: Institute of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, 10623 Berlin, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Company
authors.forename: Shenglai
authors.initials: S
authors.lastname: Yao
authors.forename: Kallol
authors.initials: K
authors.lastname: Ray
authors.forename: Matthias
authors.initials: M
authors.lastname: Driess
mesh_terms: D049308:Dioxygenases / Q000737:chemistry*; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*
chemical_list: D009532:Nickel; D049308:Dioxygenases; D010100:Oxygen