[RuCl2(η6-p-cymene)] complexes bearing phosphinous acid ligands: preparation, application in C–H bond functionalization and mechanistic investigations. Issue 15 (8th March 2016)

• Record Type: Journal Article
• Authors: Graux, Lionel V.; Giorgi, Michel; Buono, Gérard; Clavier, Hervé
• Is Part Of: Dalton transactions. Volume 45:Issue 15(2016)
• Page Start: 6491
• Page End: 6502
• Publication Date: 2016-03-08
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c5dt04683a
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : A series of [RuCl2 (η 6 - p -cymene)] complexes bearing phosphinous acid (PA) ligands have been straightforwardly prepared from the dimer [RuCl2 ( p -cymene)]2 and secondary phosphine oxides (SPOs) and fully characterized. Abstract : A series of [RuCl2 (η 6 - p -cymene)] complexes bearing phosphinous acid (PA) ligands have been straightforwardly prepared from the dimer [RuCl2 ( p -cymene)]2 and secondary phosphine oxides (SPOs) and fully characterized. The steric parameter quantification of PAs, other L ligands and η 6 - p -cymene allowed a better comprehension of the coordination chemistry of these types of complexes and explained the absence of coordination in the case of bulky SPOs such as Ad2 P(O)H. These complexes were tested in the C–H activation/functionalization of 2-phenylpyridine and a good activity was obtained at 80 °C for the complex exhibiting the highest steric bulk. A study on halide effects, either on the ruthenium complex or for the aryl halide partner, has also been carried out showing drastic differences. Further investigations on halide effects were performed notably by using a cationic ruthenacycle which was found to be an intermediate for the reaction. In order to rationalize the role played by the phosphinous acid, a mechanism involving a concerted metallation deprotonation favored by a phosphinito species has been proposed.