Arene CH Amination at Nickel in Terphenyl–Diphosphine Complexes with Labile Metal–Arene Interactions. Issue 48 (14th October 2013)

• Record Type: Journal Article
• Authors: Herbert, David E.; Lara, Nadia C.; Agapie, Theodor
• Is Part Of: Chemistry. Volume 19:Issue 48(2013)
• Page Start: 16453
• Page End: 16460
• Publication Date: 2013-10-14
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201302539
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The <italic>meta</italic>‐terphenyl diphosphine, <italic>m</italic>‐P<sub>2</sub>, <bold>1</bold>, was utilized to support Ni centers in the oxidation states 0, I, and II. A series of complexes bearing different substituents or ligands at Ni was prepared to investigate the dependence of metal–arene interactions on oxidation state and substitution at the metal center. Complex (<italic>m</italic>‐P<sub>2</sub>)Ni (<bold>2</bold>) shows strong Ni<sup>0</sup>–arene interactions involving the central arene ring of the terphenyl ligand both in solution and the solid state. These interactions are significantly less pronounced in Ni<sup>0</sup> complexes bearing L‐type ligands (<bold>2‐L</bold>: L=CH<sub>3</sub>CN, CO, Ph<sub>2</sub>CN<sub>2</sub>), Ni<sup>I</sup>X complexes (<bold>3‐X</bold>: X=Cl, BF<sub>4</sub>, N<sub>3</sub>, N<sub>3</sub>B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>), and [(<italic>m</italic>‐P<sub>2</sub>)Ni<sup>II</sup>Cl<sub>2</sub>] (<bold>4</bold>). Complex <bold>2</bold> reacts with substrates, such as diphenyldiazoalkane, sulfur ylides (Ph<sub>2</sub>SCH<sub>2</sub>), organoazides (RN<sub>3</sub>: R=<italic>para</italic>‐C<sub>6</sub>H<sub>4</sub>OMe, <italic>para</italic>‐C<sub>6</sub>H<sub>4</sub>CF<sub>3</sub>, 1‐adamantyl), and N<sub>2</sub>O with the locus of observed reactivity dependent on the nature of the substrate. These reactions led to isolation of an η<sup>1</sup>‐diphenyldiazoalkane adduct (<bold>2‐Ph<sub>2</sub>CN<sub>2</sub></bold>), methylidene insertion into a NiP bond followed by rearrangement of a nickel‐bound phosphorus ylide (<bold>5</bold>) to a benzylphosphine (<bold>6)</bold>, Staudinger oxidation of the phosphine arms, and metal‐mediated nitrene insertion into an arene CH bond of <bold>1</bold>, all derived from the same compound (<bold>2</bold>). Hydrogen‐atom abstraction from a Ni<sup>I</sup>–amide (<bold>9</bold>) and the resulting nitrene transfer supports the viability of Ni–imide intermediates in the reaction of <bold>1</bold> with 1‐azido‐arenes.</p> </abstract>