The Cl2(PCy3)(IMes)Ru(CHPh) catalyst: olefin metathesis versus olefin isomerization

Bourgeois, Damien; Pancrazi, Ange; Nolan, Steven P.; Prunet, Joëlle

doi:10.1016/s0022-328x(01)01269-4

Cited by 136 publications

(94 citation statements)

References 23 publications

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“…Besides competitive isomerization of the olefins, [38] the steric hindrance of the neopentylic vinyl substituent could also impair the reaction. In the case of a monosilylated 1,2-diol, only one isomer appeared to be reactive, and desilylated cyclized products were obtained in low yields after eight days when using 10 mol % of 3 or 5 as the catalyst; cyclooctenes in which the double bond had migrated were formed as by-products (Scheme 7).…”

Section: Annulated Eight-membered Ringsmentioning

confidence: 99%

Selective Construction of Carbocyclic Eight‐Membered Rings by Ring‐Closing Metathesis of Acyclic Precursors

2006

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Although the efficient preparation of cyclooctanoids has remained a long-standing objective, a real breakthrough was possible only relatively recently with the development of more specific reagents and by the development of new reactions. The direct construction of carbocyclic eight-membered rings from acyclic precursors is still a challenge, mainly because of unfavorable entropic and enthalpic factors that preclude ring formation. This Minireview describes the utilization of ring-closing metathesis (RCM) as a new approach to synthesize cyclooctanoids.

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Section: Annulated Eight-membered Ringsmentioning

confidence: 99%

Selective Construction of Carbocyclic Eight‐Membered Rings by Ring‐Closing Metathesis of Acyclic Precursors

2006

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“…Neben konkurrierenden Isomerisierungen der Olefine [38] kann die sterische Hinderung des neopentylischen Vinylsub- Gänzlich unerwartet ist, dass im Fall des cyclischen Carbonats erneut nur ein Diastereomer mit den Katalysatoren 1 und 3 reagiert. Hierbei kommt es zur selektiven Bildung von trans-Cycloocten mit einer Ausbeute von 34 bis 41 % je nach Katalysator (Schema 9).…”

Section: Anellierte Achtgliedrige Ringeunclassified

Selektiver Aufbau achtgliedriger Carbocyclen durch Ringschlussmetathese acyclischer Vorstufen

Michaut¹,

Rodríguez²

2006

Angewandte Chemie

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Bei der Synthese von Cyclooctanoiden kam es in jüngster Zeit zu bemerkenswerten Fortschrittten dank der Entwicklung von hochspezifisch wirkenden Reagentien und der Entdeckung neuartiger Reaktionen. Trotzdem bleibt der direkte Aufbau achtgliedriger Carbocyclen aus acyclischen Vorstufen eine Herausforderung, da entropische und enthalpische Faktoren für die Bildung von Ringen dieser Größe nachteilig sind. Dieser Kurzaufsatz beschreibt die Anwendung der Ringschlussmetathese (RCM) als eine neue Methode zur Synthese von Cyclooctanoiden.

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“…Thus, with the 2nd generation Grubbs catalyst (1), isomerization induced by in situ generated ruthenium-hydride complexes [4][5][6][7][8]21,22] is negatively influencing the yield and product selectivity, creating difficulties in product separation and purification. Olefin isomerization has been decreased by the addition of electron-deficient benzoquinones (e.g., 1,4-benzoquinones, 10 mol %), tricyclohexylphosphine oxide (0.5 mol %) or phenylphosphoric acid (5 mol %), as well as quinone-containing Hoveyda-type complexes [23][24][25][26][27]. Also proved was that for other 2nd generation Ru metathesis catalysts, the contribution of the isomerization pathway hinges on the catalyst loading [28].…”

Section: Introductionmentioning

confidence: 96%

Unprecedented Multifunctionality of Grubbs and Hoveyda–Grubbs Catalysts: Competitive Isomerization, Hydrogenation, Silylation and Metathesis Occurring in Solution and on Solid Phase

Martinez-Amezaga¹,

Delpiccolo²,

Méndez³

et al. 2017

Catalysts

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This contribution showcases the interplay of several non-metathetic reactions (isomerization, silylation and "hydrogen-free" reduction) with metathesis in systems comprising a functionalized olefin and a soluble or resin-immobilized silane. These competing, one-pot reactions occur under activation by second-generation Ru-alkylidene catalysts. Different olefinic substrates were used to study the influence of the substitution pattern on the reaction outcome. Emphasis is placed upon the rarely reported yet important transformations implying a solid phase-supported silane reagent. Catalytic species involved in and reaction pathways accounting for these concurrent processes are evidenced. An unexpected result of this research was the clearly proved partial binding of the olefin to the resin, thereby removing it from the reacting ensemble.

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The Cl2(PCy3)(IMes)Ru(CHPh) catalyst: olefin metathesis versus olefin isomerization

Cited by 136 publications

References 23 publications

Selective Construction of Carbocyclic Eight‐Membered Rings by Ring‐Closing Metathesis of Acyclic Precursors

Selective Construction of Carbocyclic Eight‐Membered Rings by Ring‐Closing Metathesis of Acyclic Precursors

Selektiver Aufbau achtgliedriger Carbocyclen durch Ringschlussmetathese acyclischer Vorstufen

Unprecedented Multifunctionality of Grubbs and Hoveyda–Grubbs Catalysts: Competitive Isomerization, Hydrogenation, Silylation and Metathesis Occurring in Solution and on Solid Phase

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