Direct Observation of a 14-Electron Ruthenacyclobutane Relevant to Olefin Metathesis
- 17 March 2005
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 127 (14) , 5032-5033
- https://doi.org/10.1021/ja042259d
Abstract
The 14-electron ruthenium phosphonium alkylidene complex [(IH2Mes)Cl2RuCH(PCy3)][B(C6F5)4], 1b, a highly active olefin metathesis catalyst, reacts with stoichiometric quantities of ethylene at −50 °C in CD2Cl2 to generate the ruthenacyclobutane complex [(IH2Mes)Cl2RuCH2CH2CH2], 2, and [CH2CH(PCy3)][B(C6F5)4] in quantitative yield by NMR spectroscopy. 1H and 13C NMR spectroscopies on 2 and 2-13C3 are consistent with a symmetrical C2v structure, providing the first experimental information concerning this crucial intermediate in ruthenium-mediated olefin metathesis. At −50 °C, exchange with free ethylene takes place on the chemical time scale. Complex 2 decomposes in solution upon warming to room temperature, generating propene and unknown ruthenium product(s).Keywords
This publication has 20 references indexed in Scilit:
- Rapidly Initiating Ruthenium Olefin‐Metathesis CatalystsAngewandte Chemie International Edition in English, 2004
- Mechanism of Ruthenium-Catalyzed Olefin Metathesis Reactions from a Theoretical PerspectiveJournal of the American Chemical Society, 2002
- Novel η3-Vinylcarbene Complexes Derived from Ruthenium-Based Olefin Metathesis CatalystsOrganometallics, 2001
- ComparingGrubbs-,Werner-, andHofmann-Type (Carbene)ruthenium Complexes: The Key Role of Pre-Equilibria for Olefin MetathesisHelvetica Chimica Acta, 2000
- Ruthenium-Based Four-Coordinate Olefin Metathesis CatalystsPublished by Wiley ,2000
- Mechanistic Studies of Olefin Metathesis by Ruthenium Carbene Complexes Using Electrospray Ionization Tandem Mass SpectrometryJournal of the American Chemical Society, 2000
- A Recyclable Ru-Based Metathesis CatalystJournal of the American Chemical Society, 1999
- C−C and C−H Bond Activation at Ruthenium(II): The Stepwise Degradation of a Neopentyl Ligand to a Trimethylenemethane LigandJournal of the American Chemical Society, 1997
- Well-Defined Ruthenium Olefin Metathesis Catalysts: Mechanism and ActivityJournal of the American Chemical Society, 1997
- Cyclometallation of phenylphosphine and neopentyl ligands in ruthenium(II) complexes: synthesis and crystal structure of the orthometallated complexes [Ru(C6H4PR1R2)(CH2CMe3)(η6-C6Me6)](R1= R2= Ph; R1= Me, R2= Ph; R1= R2= Me) and of the metallacyclobutanes [Ru(CH2CMe2CH2)(η-C6Me6)(PPhR1R2)](R1= R2= Ph; R1= Me, R2= Ph)J. Chem. Soc., Dalton Trans., 1991