Binuclear, High‐Valent Nickel Complexes: Ni−Ni Bonds in Aryl–Halogen Bond Formation. Issue 13 (14th February 2017)

• Record Type: Journal Article
• Authors: Diccianni, Justin B.; Hu, Chunhua; Diao, Tianning
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 13(2017)
• Page Start: 3635
• Page End: 3639
• Publication Date: 2017-02-14
• Subjects: C−X bond formation -- mixed-valent compounds -- nickel–nickel bond -- reaction mechanisms -- reductive elimination; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201611572
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Metal–metal bonds play a vital role in stabilizing key intermediates in bond‐formation reactions. We report that binuclear benzo[ h ]quinoline‐ligated Ni II complexes, upon oxidation, undergo reductive elimination to form carbon–halogen bonds. A mixed‐valent Ni(2.5+)–Ni(2.5+) intermediate is isolated. Further oxidation to Ni III, however, is required to trigger reductive elimination. The binuclear Ni III –Ni III intermediate lacks a Ni−Ni bond. Each Ni III undergoes separate, but fast reductive elimination, giving rise to Ni I species. The reactivity of these binuclear Ni complexes highlights the fundamental difference between Ni and Pd in mediating bond‐formation processes. Abstract : A couple of nickels : Well‐defined, binuclear Ni II –Ni II, Ni(2.5+)–Ni(2.5+), and Ni III –Ni III complexes are isolated, which shed light on the mechanism of reductive elimination to form carbon–halogen bonds. Their reactivity is fundamentally different to that of the related palladium complexes.