C−C Bond Formation via C−H Bond Activation Using an in Situ-Generated Ruthenium Catalyst

Martinez, Rémi; Simon, Marc‐Olivier; Chevalier, Reynald; Pautigny, Cyrielle; Genêt, Jean‐Pierre; Darses, Sylvain

doi:10.1021/ja9017489

Cited by 142 publications

(45 citation statements)

References 99 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…From a practical point of view, it is highly desired that the reaction could be conducted on a large scale without a solvent. The reaction of 35 mmol of 7a with 80 mmol of 8a afforded 9a with a high TON of 837, which is slightly lower than the highest value (1125) reported for homogeneous ruthenium catalysts [35]. We deduced that a high reaction temperature, 170°C, would be required for in situ generation of catalytically active species, presumably reduced surface ruthenium phosphine complexes.…”

mentioning

confidence: 62%

“…In particular, the asymmetric hydrogenation developed by Noyori et al [32] and the alkene metathesis developed by Grubbs et al [33] are the most prominent achievements realized by ruthenium complex catalysts. In addition, carbon-carbon bond formations via the activation of stable C-H bonds [34,35] and unstrained C-C bonds [36,37] have been achieved by the use of low-valent ruthenium complex catalysts. Despite the excellent activities and selectivities, these homogeneous catalysts have significant drawbacks for practical uses such as the high cost of catalyst production, high sensitivity towards air and moisture, problems in the catalyst separation, and so on.…”

Section: Ru/ceo -Catalyzed Organic Transformations Via Stable C-h or mentioning

confidence: 99%

See 1 more Smart Citation

Development of Ceria-Supported Ruthenium Catalysts Effective for Various Synthetic Reactions

2010

View full text Add to dashboard Cite

Our recent results on organic transformations such as C-C bond formation via the activation of stable C-C or C-H bonds and aerobic oxidation of alcohols catalyzed by CeO 2 -supported ruthenium are reviewed. A simple, recyclable heterogeneous Ru/CeO 2 catalyst showed excellent activity for sequential transfer-allylation/ isomerization of homoallyl alcohols with aldehydes to saturated ketones via the C-C bond activation. While homogeneous ruthenium and rhodium complex catalysts require additives and/or pressurized CO, the reaction with Ru/CeO 2 smoothly proceeded in the absence of any additives. The Ru/CeO 2 catalyst also showed excellent activity for the addition of sp 2 C-H bonds of aromatic ketones to vinylsilanes. The Ru/CeO 2 catalyst realized the chelationassisted arylation of stable aromatic C-H bonds with aryl chlorides. The activity of the catalyst was greatly improved by the PPh 3 -modification under hydrogen atmosphere prior to the reactions. The catalyst acts heterogeneously without a significant leaching of ruthenium species, indicating that the Ru/CeO 2 catalyst has an advantage over homogeneous catalysts from practical and environmental points of view. The effects of chemical and physical properties of CeO 2 on the activity of CeO 2 -supported noble metal catalysts were examined. Porous CeO 2 powders were prepared by the coagulation of solvothermally synthesized colloidal ceria nanoparticles, and the thus-prepared CeO 2 powders showed an oxygen migration ability far superior to the CeO 2 samples prepared by the usual precipitation method. The ruthenium catalysts supported on the former CeO 2 powders showed a high activity for the aerobic oxidation of benzyl alcohol. The effects of the pore structure of CeO 2 powders on the activity of the Ru/CeO 2 catalysts are also discussed.

show abstract

mentioning

confidence: 62%

Section: Ru/ceo -Catalyzed Organic Transformations Via Stable C-h or mentioning

confidence: 99%

Development of Ceria-Supported Ruthenium Catalysts Effective for Various Synthetic Reactions

2010

View full text Add to dashboard Cite

show abstract

“…28 No entanto, outros metais são também empregados, e.g., ródio 38 e rutênio, 39 atuando muitas vezes de forma precisa cirúrgica, realizando com maestria o que paládio não faz, ou não faz muito bem em determinadas condições. Do ponto de vista sintético, embora o paládio esteja sempre na vanguarda, os três metais de transição são ferramentas valiosíssimas.…”

Section: Esquema 7 Cicloaromatização De Alcinos Com Duas Ativações Dunclassified

O desafio da ativação das ligações C-H em síntese orgânica

Correia¹

2011

Quím. Nova

View full text Add to dashboard Cite

Recebido em 11/3/11; aceito em 9/6/11; publicado na web em 9/8/11 THE CHALLENGE OF C-H ACTIVATION IN ORGANIC SYNTHESIS. This review aims at to the presentation and discussion of the principal aspects of the C-H activation by transition metals. Representative examples were selected from the recent literature to illustrate these principles beginning with somewhat simple examples and moving up to more complex ones. The synthetic potential of the C-H activation, as well as the potential advantages and disadvantages of the methodology are highlighted with relevant recent examples, along with brief insights on the mechanism aspects of these reactions.Keywords: C-H activation; transition metals; organic synthesis.Em linhas gerais, para que uma reação orgânica aconteça é preciso que haja uma ligação química suscetível, de forma geral, à clivagem, migração, substituição e/ou adição. Naturalmente, tal ocorrência é induzida por um agente externo, seja ele uma molécula, uma fonte de energia, ou até mesmo outra parte da mesma molécula. Frequentemente, a ligação química em questão é relativamente ativada, isto é, possui patamar energético relativamente elevado, o que facilita sua manipulação sintética. Logo, é desejável que os substratos envolvidos em uma reação sejam previamente funcionalizados, ou seja, contenham sítios reacionais cuja natureza seja suscetível às condições do meio reacional.Frequentemente, utiliza-se o termo "ativação" para designar o aumento da reatividade de uma ligação/molécula frente a algum reagente ou condição reacional. Em muitos casos, o termo "ativação" implica na ruptura da ligação química. O principal resultado da ativação de uma ligação C-H é a sua substituição por uma ligação mais fraca/mais funcionalizada (i.e., mais suscetível a outras reações). Por exemplo, um composto insaturado pode ser ativado mediante coordenação a um centro metálico dos seus orbitais π. Entretanto, para um composto saturado esta rota não é possível e outros mecanismos devem ser utilizados. 1 Sobre as ligações C-H e a sua ativação, três informações básicas precisam ser previamente fornecidas: a ligação carbono-hidrogênio é uma das mais estáveis que existem, isto é, é termodinamicamente estável e cineticamente inerte; é uma ligação onipresente em compostos orgânicos; o maior estoque de moléculas orgânicas são as reservas de petróleo e gás natural, ou seja, a vasta maioria das matérias-primas da química são hidrocarbonetos. Logo, a ativação da ligação carbonohidrogênio (ativação C-H) não é nova. 1 Pelo contrário, a humanidade ainda estaria nos primórdios da evolução tecnológica caso não houvessem desenvolvimentos nesta área.O aproveitamento mais direto dos hidrocarbonetos, particularmente dos alcanos, é proporcionado pelo oxigênio, pois estes sofrem, a temperaturas devidas, oxidação completa, ou queima, fornecendo água, dióxido de carbono e muito calor. No entanto, à temperatura ambiente, sem a presença de um catalisador, os alcanos são praticamente inertes ao oxigênio atmosférico. Esta dicotomia, relacionada aos alcanos, ...

show abstract

“…Significant achievements in this field have already been reached using palladium [2, 3] and rhodium [4] catalysts. Ruthenium(0) [5,6] and recently ruthenium(II) [7][8][9][10][11] systems have contributed to the functionalization of CÀH bonds through two different processes. In parallel, the contribution of various metal catalysts for the functionalization of CÀH bonds has also been reported.…”

mentioning

confidence: 99%

CH Bond Functionalization in Water Catalyzed by Carboxylato Ruthenium(II) Systems

et al. 2010

View full text Add to dashboard Cite

Direct metal-catalyzed C À H bond activation/functionalization reactions have become a topic of tremendous interest [1] owing to their potential to replace the classical catalytic crosscoupling reactions, without the intermediate formation of organometallic C-M species (M = metal center). Significant achievements in this field have already been reached using palladium [2, 3] and rhodium [4] catalysts. Ruthenium(0) [5,6] and recently ruthenium(II) [7][8][9][10][11] systems have contributed to the functionalization of CÀH bonds through two different processes. In parallel, the contribution of various metal catalysts for the functionalization of CÀH bonds has also been reported. [12] For the formation of C À C bonds directly from aromatic sp 2 C À H bonds, initial studies suggested an electrophilic substitution reaction of the arene by Pd II or Ru IV species that are generated in situ from aryl bromide or aryl iodide oxidative addition to the Pd 0 and Ru II catalysts. Significant recent contributions by Fagnou and co-workers [3a-d] and Echavarren, Maseras, and co-workers [13] based on both experimental studies with Pd 0 catalysts and density functional theory (DFT) calculations, support a concerted metalationdeprotonation mechanism. With ruthenium(II) catalysts, the influence of coordinated carbonate, as supported by DFT calculations, indicates a mechanism based on the cooperative actions of both the Ru II site and the carbonate ligand for C À H bond deprotonation. This step generates a cyclometalated species before the oxidative addition of arylhalides. [9] [Eq. (1); X = halide, carboxylate; Y = OH, Me]. This result revealed the tremendous positive influence of coordinated carboxylate ligands, assisted by ruthenium(II), for CÀH bond functionalization.[10] The beneficial influence of a carboxylate ligand coordinated to Pd II [3] and Ru II centers [8d] has also been demonstrated.The concerted intramolecular deprotonation of inert C À H bonds with the assistance of a coordinated ligand appears to be a general phenomenon. [14,15] This intramolecular C À H bond deprotonation mechanism, rather than an electrophilic substitution, suggests that such a process could take place in water with ruthenium(II) catalytic systems, as some ruthenium(II) catalysts have already been shown to be stable for several catalytic transformations in water.[16] Catalysis in water is developing not only to avoid the use of organic solvents as reaction medium but also to reach better catalytic activity and regioselectivity. [17,18] A few examples of palladium-catalyzed CÀH bond functionalization in water have just been shown, [18,19] including the ortho CÀH bond functionalization by Lipshutz and coworkers for the coupling of arylureas with aryl iodide and for the alkenylation of phenylamides in the presence of a surfactant. [19] We now report that [Ru(O 2 CR) 2 (arene)] catalysts 1) can efficiently perform the direct ortho arylation of functional arenes with aryl chlorides in water, without the need for surfactant, 2) when they operate in...

show abstract

C−C Bond Formation via C−H Bond Activation Using an in Situ-Generated Ruthenium Catalyst

Cited by 142 publications

References 99 publications

Development of Ceria-Supported Ruthenium Catalysts Effective for Various Synthetic Reactions

Development of Ceria-Supported Ruthenium Catalysts Effective for Various Synthetic Reactions

O desafio da ativação das ligações C-H em síntese orgânica

CH Bond Functionalization in Water Catalyzed by Carboxylato Ruthenium(II) Systems

Contact Info

Product

Resources

About