Ammonium NHC-tagged olefin metathesis catalysts – influence of counter-ions on catalytic activity

2018 ◽  
Vol 42 (11) ◽  
pp. 8609-8614 ◽  
Author(s):  
Andrzej Tracz ◽  
Anna Gawin ◽  
Michał Bieniek ◽  
Tomasz K. Olszewski ◽  
Krzysztof Skowerski
Keyword(s):  
Catalytic Activity ◽  
Quaternary Ammonium ◽  
Olefin Metathesis ◽  
Counter Ions ◽  
Metathesis Catalysts

Ruthenium-based catalysts bearing quaternary ammonium groups in their N-heterocyclic carbene (NHC) fragments and different counter-ions were synthesised and tested in various olefin metathesis transformations.

Quest for the ideal olefin metathesis catalyst

2008 ◽  
Vol 80 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Anna Michrowska ◽  
Karol Grela
Keyword(s):  
Oxygen Atom ◽  
Quaternary Ammonium ◽  
Olefin Metathesis ◽  
Amino Group ◽  
Sulfonated Polystyrene ◽  
Grubbs Catalyst ◽  
Metathesis Catalyst ◽  
Metathesis Catalysts ◽  
Novel Strategy ◽  
The Ideal

Attempts were made to create a catalyst that approaches Gladysz's vision of an "ideal catalyst". Modifications of the Hoveyda-Grubbs catalyst were carried out with the aim to increase its activity and broaden the scope of its applicability to challenging metathesis reactions. This was done by introduction of an electron-withdrawing substituent on the isopropoxybenzylidene group in order to diminish the donor properties of the oxygen atom. The resulting stable and easily accessible nitro-substituted Hoveyda-Grubbs catalyst has found a number of successful applications in various research and industrial laboratories. Also, a new concept for noncovalent immobilization of a ruthenium olefin metathesis catalyst is presented. The 2-isopropoxybenzylidene ligand of Hoveyda-Grubbs carbene is further modified by an additional amino group, and immobilization is achieved by treatment with sulfonated polystyrene, forming the corresponding ammonium salt. In this novel strategy for the immobilization of ruthenium-based metathesis catalysts, the amino group plays a dual role, being first an active anchor for immobilization and secondly, after protonation, activating the catalysts by electron-donating to -withdrawing switch. The same concept has been used in the preparation of a quaternary ammonium catalyst for aqueous olefin metathesis.

Ru-Based Complexes with Quaternary Ammonium Tags Immobilized on Mesoporous Silica as Olefin Metathesis Catalysts

ACS Catalysis ◽  
2014 ◽  
Vol 4 (9) ◽  
pp. 3227-3236 ◽  
Author(s):  
Jakub Pastva ◽  
Krzysztof Skowerski ◽  
Stefan J. Czarnocki ◽  
Naděžda Žilková ◽  
Jiří Čejka ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Quaternary Ammonium ◽  
Olefin Metathesis ◽  
Metathesis Catalysts

scholarly journals Correction to Ru-Based Complexes with Quaternary Ammonium Tags Immobilized on Mesoporous Silica as Olefin Metathesis Catalysts

ACS Catalysis ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 2542-2542
Author(s):  
Jakub Pastva ◽  
Krzysztof Skowerski ◽  
Stefan J. Czarnocki ◽  
Naděžda Žilková ◽  
Jiří Čejka ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Quaternary Ammonium ◽  
Olefin Metathesis ◽  
Metathesis Catalysts

Activated Hoveyda‐Grubbs Olefin Metathesis Catalysts Derived from a Large Scale Produced Pharmaceutical Intermediate—Sildenafil Aldehyde

2021 ◽  
Author(s):  
Louis Monsigny ◽  
Jakub Piątkowski ◽  
Damian Trzybiński ◽  
Krzysztof Wozniak ◽  
Tomasz Nienałtowski ◽  
...  
Keyword(s):  
Olefin Metathesis ◽  
Large Scale ◽  
Metathesis Catalysts

Nitrenium ions and trivalent boron ligands as analogues of N-heterocyclic carbenes in olefin metathesis: a computational study

2015 ◽  
Vol 44 (46) ◽  
pp. 20021-20026 ◽  
Author(s):  
A. Pazio ◽  
K. Woźniak ◽  
K. Grela ◽  
B. Trzaskowski
Keyword(s):  
Olefin Metathesis ◽  
Computational Study ◽  
Heterocyclic Carbenes ◽  
Mechanistic Study ◽  
Nitrenium Ions ◽  
Nitrenium Ion ◽  
Metathesis Catalysts

A DFT mechanistic study reveals that nitrenium ion-modified Hoveyda-like complexes are good candidates for latent metathesis catalysts, while boron-modified systems are candidates for very fast metathesis catalysts.

Sign in / Sign up

Export Citation Format

Share Document