Unexpected Vulnerability of DPEphos to C−O Activation in the Presence of Nucleophilic Metal Hydrides

Mateusz K. Cybulski, Nicholas A. Beattie, Stuart A. Macgregor*, Mary F. Mahon, Michael K. Whittlesey*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

C−O bond activation of DPEphos occurs upon mild heating in the presence of [Ru(NHC)2(PPh3)2H2] (NHC=N-heterocyclic carbene) to form phosphinophenolate products. When NHC=IEt2Me2, C−O activation is accompanied by C−N activation of an NHC ligand to yield a coordinated N-phosphino-functionalised carbene. DFT calculations define a nucleophilic mechanism in which a hydride ligand attacks the aryl carbon of the DPEphos C−O bond. This is promoted by the strongly donating NHC ligands which render a trans dihydride intermediate featuring highly nucleophilic hydride ligands accessible. C−O bond activation also occurs upon heating cis-[Ru(DPEphos)2H2]. DFT calculations suggest this reaction is promoted by the steric encumbrance associated with two bulky DPEphos ligands. Our observations that facile degradation of the DPEphos ligand via C−O bond activation is possible under relatively mild reaction conditions has potential ramifications for the use of this ligand in high-temperature catalysis.

Original languageEnglish
Pages (from-to)11141-11145
Number of pages5
JournalChemistry - A European Journal
Volume26
Issue number49
Early online date28 Jul 2020
DOIs
Publication statusPublished - 1 Sept 2020

Keywords

  • C−O bond activation
  • density functional calculations
  • hydride ligands
  • N-heterocyclic carbenes
  • phosphines

Fingerprint

Dive into the research topics of 'Unexpected Vulnerability of DPEphos to C−O Activation in the Presence of Nucleophilic Metal Hydrides'. Together they form a unique fingerprint.

Cite this