Adamantyl-SubstitutedN-Heterocyclic Carbene Ligands in Second-Generation Grubbs-Type Metathesis Catalysts

Phosphine-scavenging Merrifield resins can significantly facilitate the synthesis of highly active Ru metathesis catalysts, including the second-generation Grubbs, Hoveyda, and indenylidene catalysts (GII, HII, InII).

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Consequences of the electronic tuning of latent ruthenium-based olefin metathesis catalysts on their reactivity

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.11.158 ◽

2015 ◽

Vol 11 ◽

pp. 1458-1468 ◽

Cited By ~ 6

Author(s):

Karolina Żukowska ◽

Eva Pump ◽

Aleksandra E Pazio ◽

Krzysztof Woźniak ◽

Luigi Cavallo ◽

...

Keyword(s):

High Temperatures ◽

Olefin Metathesis ◽

Minor Amount ◽

Carbene Ligands ◽

Enhanced Activity ◽

Electronic Tuning ◽

Metathesis Catalysts ◽

A Minor ◽

Factor Governing

Two ruthenium olefin metathesis initiators featuring electronically modified quinoline-based chelating carbene ligands are introduced. Their reactivity in RCM and ROMP reactions was tested and the results were compared to those obtained with the parent unsubstituted compound. The studied complexes are very stable at high temperatures up to 140 °C. The placement of an electron-withdrawing functionality translates into an enhanced activity in RCM. While electronically modified precatalysts, which exist predominantly in the trans-dichloro configuration, gave mostly the RCM and a minor amount of the cycloisomerization product, the unmodified congener, which preferentially exists as its cis-dichloro isomer, shows a switched reactivity. The position of the equilibrium between the cis- and the trans-dichloro species was found to be the crucial factor governing the reactivity of the complexes.

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Comparing Intrinsic Reactivities of the First- and Second-Generation Ruthenium Metathesis Catalysts in the Gas Phase

Helvetica Chimica Acta ◽

10.1002/hlca.200390112 ◽

2003 ◽

Vol 86 (4) ◽

pp. 941-949 ◽

Cited By ~ 38

Author(s):

Christian Adlhart ◽

Peter Chen

Keyword(s):

Gas Phase ◽

Second Generation ◽

Metathesis Catalysts ◽

First And Second Generation

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Ru-based Z-selective metathesis catalysts with modified cyclometalated carbene ligands

Chemical Science ◽

10.1039/c4sc01541j ◽

2014 ◽

Vol 5 (10) ◽

pp. 4091-4098 ◽

Cited By ~ 26

Author(s):

Sarah M. Bronner ◽

Myles B. Herbert ◽

Paresma R. Patel ◽

Vanessa M. Marx ◽

Robert H. Grubbs

Keyword(s):

Olefin Metathesis ◽

Carbene Ligands ◽

Metathesis Catalysts

A series of cyclometalated Z-selective ruthenium olefin metathesis catalysts with alterations to the N-heterocyclic carbene (NHC) ligand were prepared.

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Ruthenium Olefin Metathesis Catalysts with N-Heterocyclic Carbene Ligands BearingN-Naphthyl Side Chains

Organometallics ◽

10.1021/om9009697 ◽

2010 ◽

Vol 29 (4) ◽

pp. 775-788 ◽

Cited By ~ 46

Author(s):

Ludovic Vieille-Petit ◽

Hervé Clavier ◽

Anthony Linden ◽

Sascha Blumentritt ◽

Steven P. Nolan ◽

...

Keyword(s):

Olefin Metathesis ◽

Side Chains ◽

Carbene Ligands ◽

Metathesis Catalysts

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A thermally robust ruthenium phosphonium alkylidene catalyst — the effect of more bulky N-heterocyclic carbene ligands on catalyst performance in olefin metathesis reactions

Canadian Journal of Chemistry ◽

10.1139/cjc-2013-0156 ◽

2013 ◽

Vol 91 (10) ◽

pp. 935-942 ◽

Cited By ~ 9

Author(s):

Erin M. Leitao ◽

Warren E. Piers ◽

Masood Parvez

Keyword(s):

Olefin Metathesis ◽

Second Generation ◽

The Other ◽

Carbene Ligands ◽

Thermal Stabilities ◽

Excellent Activity ◽

Metathesis Reactions ◽

Test Reactions ◽

Overall Efficiency ◽

Alkylidene Complexes

Three new ruthenium phosphonium alkylidene complexes incorporating N-heterocyclic carbene ligands with bulky N-aryl groups (2,6-diethyl, L = 1,3-bis(2,6-diethylphenyl)imidazolin-2-ylidene (H2IDEP) and 2,6-diisopropyl, L = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene (H2ID-i-PP)) were synthesized and characterized. The H2ID-i-PP supported complex was found to exhibit excellent thermal stabilities relative to the parent N-mesityl (N-Mes) complexes as well as the H2IDEP supported complexes. All three phosphonium alkylidenes were evaluated in comparison to the N-Mes derivative and Grubbs second generation catalyst using standard olefin metathesis reactions and conditions. The complex containing the bulky H2ID-i-PP ligand was found to have excellent activity and longevity in comparison to the other catalysts. Although initiation rates were slow for this sterically bulky precatalyst, its superior activity led to the best overall efficiency in test reactions.

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Ruthenium Olefin Metathesis Catalysts Featuring N-Heterocyclic Carbene Ligands Tagged with Isonicotinic and 4-(Dimethylamino)benzoic Acid Rests: Evaluation of a Modular Synthetic Strategy

Molecules ◽

10.3390/molecules26175220 ◽

2021 ◽

Vol 26 (17) ◽

pp. 5220

Author(s):

Stefan Czarnocki ◽

Louis Monsigny ◽

Michał Sienkiewicz ◽

Anna Kajetanowicz ◽

Karol Grela

Keyword(s):

Benzoic Acid ◽

Olefin Metathesis ◽

Ruthenium Catalysts ◽

Benzoic Acids ◽

Carbene Ligands ◽

Synthetic Strategy ◽

Starting Point ◽

Brønsted Base ◽

Metathesis Catalysts

A modular and flexible strategy towards the synthesis of N-heterocyclic carbene (NHC) ligands bearing Brønsted base tags has been proposed and then adopted in the preparation of two tagged NHC ligands bearing rests of isonicotinic and 4-(dimethylamino)benzoic acids. Such tagged NHC ligands represent an attractive starting point for the synthesis of olefin metathesis ruthenium catalysts tagged in non-dissociating ligands. The influence of the Brønsted basic tags on the activity of such obtained olefin metathesis catalysts has been studied.

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