An Ionic Liquid-Supported Ruthenium Carbene Complex: A Robust and Recyclable Catalyst for Ring-Closing Olefin Metathesis in Ionic Liquids

Abstract

The synthesis of an ionic liquid-supported olefin metathesis catalyst derived from Grubb's ruthenium carbene complex is described. This new supported catalyst has been used in BMI.PF6 solvent, and this allowed success in solving the challenging problem of catalyst recycling. The IL catalyst in BMI.PF6 can be recovered and reused up to 10 consecutive cycles in RCM reactions of several dienes with excellent conversions. Moreover, the IL catalyst shows a remarkable stability in BMI.PF6 and can be stored several months without loss of activity. These results clearly demonstrate the importance of anchoring an imidazolium ionic liquid pattern to the catalyst to avoid its leaching from the BMI.PF6 phase.

Hybrid Organic‐Inorganic Materials Derived from a Monosilylated Hoveyda‐type Ligand as Recyclable Diene and Enyne Metathesis Catalysts

“…The 29 Si solid state NMR data, some textural properties and the ligand loading of hybrid materials 8 are summarized in Table 1. 29 Si CP-MAS NMR of 8b-e confirmed the covalent bonding of the organic moiety to the matrix by the appearance of T 2 and T 3 signals due to the ligand in addition of the characteristic Q 3 and Q 4 signals due to the condensed TEOS. The 29 Si CP-MAS spectrum of 8dSi showed a signal around 11.9 ppm corresponding to the À SiMe 3 unit and the intensity of the Q 3 absorption (À103.1) decreased considerably ( Figure 2).…”

“…The mixture was filtered under nitrogen atmosphere with a cannula and the solid was washed 4 times with 4 mL portions of anhydrous dichloromethane. The combined filtrates were evaporated to yield 14 [29] Adv. Synth.…”

Metathesis of 1‐Octene in Ionic Liquids and Other Solvents: Effects of Substrate Solubility, Solvent Polarity and Impurities

“…However, attachment of an "ionic liquid tag" to catalyst ligands hugely improves the recyclability of the system. [12][13][14][15] Interestingly, neither of these nor most other studies involving transition metal catalysts attach any importance to the purity of the ionic liquid used as solvent, although it is known that impurities such as water, amines or halides, stemming from the preparation of the ionic liquid, affect the reaction outcome, especially if transition metal catalysts are used. [4,[18][19][20][21][22][23][24][25][26][27][28][29][30][31] In this sense, the conclusions drawn from this present study are certainly transferable to other catalytic reactions.…”

Synthesis, Characterization and Catalytic Polymerization of N-Methyl Imidazolium Phosphotungstic Catalyst

“…With an increase of the scan rate, the oxidation peak potential shifted more positively and the reduction potential shifted more negatively, while the peak currents increased linearly with an increase of the square of the scan rate (inset A). This revealed that the electrochemical behavior of the complex chemsorbed on the surface of the ligands showing a diffusion-confined redox process [20].…”