title: A cobalt(ii) iminoiodane complex and its scandium adduct: mechanistic promiscuity in hydrogen atom abstraction reactions.
abstract: In addition to oxometal [M(n+)[double bond, length as m-dash]O] and imidometal [M(n+)[double bond, length as m-dash]NR] units, transient metal-iodosylarene [M((n-2)+)-O[double bond, length as m-dash]IPh] and metal-iminoiodane [M((n-2)+)-N(R)[double bond, length as m-dash]IPh] adducts are often invoked as a possible "second oxidant" responsible for the oxo and imido group transfer reactivity. Although a few metal-iodosylarene adducts have been recently isolated and/or spectroscopically characterized, metal-iminoiodane adducts have remained elusive. Herein, we provide UV-Vis, EPR, NMR, XAS and DFT evidence supporting the formation of a metal-iminoiodane complex 2 and its scandium adduct 2-Sc. 2 and 2-Sc are reactive toward substrates in the hydrogen-atom and nitrene transfer reactions, which confirm their potential as active oxidants in metal-catalyzed oxidative transformations. Oxidation of para-substituted 2,6-di-tert-butylphenols by 2 and 2-Sc can occur by both coupled and uncoupled proton and electron transfer mechanisms; the exact mechanism depends on the nature of the para substituent.
authors.affiliation: Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, D-12489 Berlin, Germany. kallol.ray@chemie.hu-berlin.de.
authors.forename: Subrata
authors.initials: S
authors.lastname: Kundu
authors.forename: Petko
authors.initials: P
authors.lastname: Chernev
authors.forename: Xenia
authors.initials: X
authors.lastname: Engelmann
authors.forename: Chan Siu
authors.initials: CS
authors.lastname: Chung
authors.forename: Holger
authors.initials: H
authors.lastname: Dau
authors.forename: Eckhard
authors.initials: E
authors.lastname: Bill
authors.forename: Jason
authors.initials: J
authors.lastname: England
authors.forename: Wonwoo
authors.initials: W
authors.lastname: Nam
authors.forename: Kallol
authors.initials: K
authors.lastname: Ray