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1
Massouh, Joe. "Transition metals-catalyzed C(sp2)-H bond activation for aldehyde functionalization". Electronic Thesis or Diss., Ecole centrale de Marseille, 2022. http://www.theses.fr/2022ECDM0001.
Abstract (sommario):
La synthèse de α-cétoacide, précurseur ou analogue d’amino-acide, présente un centre d’intérêt. L’une des voies de synthèse menant à ces molécules pourrait être la fonctionnalisation directe de l’aldéhyde. L’activation de la liaison C(sp2)-H de l’aldéhyde catalysée par des complexes organométalliques est un outil puissant qui permet de synthétiser divers produits élaborés de manière relativement durable.Dans le premier chapitre de ce manuscrit, nous avons présenté les complexes organométalliques basés sur différents métaux de transition comme Rh, Co, Ru, Ni et Ir, qui sont capables d’activer sélectivement la liaison C(sp2)-H de l’aldéhyde. Les procédures rapportées impliquent des métaux de transition à faible degré d’oxydation favorisant le mécanisme d’addition oxydante, ou à haut degré d’oxydation favorisant le processus de métallation-déprotonation concertée. Cette présentation permet de montrer les avantages et les inconvénients de chaque approche et met en évidence la nouveauté de chaque concept.Dans le deuxième chapitre, selon la bibliographie, des procédures ont été étudiées pour réaliser la fonctionnalisation de la C-H liaison de l’aldéhyde avec divers réactifs, notamment le dioxyde de carbone. Divers métaux de transition à bas degré d’oxydation ont été étudiés, et la réactivité du substrat aldéhyde est restée limitée à la catalyse au Rh(I). Dans le cas des métaux de transition à haut degré d’oxydation, le complexe catalytique Rh(III) s’est avéré efficace pour accéder à une nouvelle voie de synthèse vers des imides avec de bons rendements (jusqu’à 97%) en utilisant des dioxazolones. De nombreux paramètres affectant l’activation C-H de l’aldéhyde ont été examinés et les études mécanistiques ont été étayées par des tests de marquage. Malheureusement, nous avons observé que certains systèmes catalytiques capables de réaliser une fonctionnalisation de liaison aromatique C(sp2)-H avec du dioxyde de carbone, n’étaient pas efficaces pour catalyser la carboxylation de la liaison C(sp2)-H d’aldéhydes. Le troisième chapitre contient les procédures expérimentales et la caractérisation des nouveaux produits, notamment les imidesThe synthesis of α-ketoacid, precursor or analogue of amino-acid, presents a center of interest. One of the synthetic pathways leading to these molecules could be the direct functionalization of aldehyde. The C(sp2)-H bond activation of aldehyde catalyzed by organometallic complexes is a powerful tool to afford various elaborated products in a relatively sustainable manner.In the first chapter of this manuscript, we presented the organometallic complexes based on different transition metals like Rh, Co, Ru, Ni, and Ir, that are able to activate selectively the C(sp2)-H bond of aldehyde. The reported procedures involve transition metals at low oxidation state favoring the oxidative addition mechanism, or at high oxidation state favoring the concerted metalation deprotonation process. This presentation allows to display the advantages and the drawbacks of each approach and highlights the novelty in each concept.In the second chapter, according to bibliography, procedures were investigated to achieve aldehyde C-H functionalization with various reagents, notably carbon dioxide. Various transition metals at low oxidation states were studied, and the reactivity of the aldehyde substrate remained restricted to the reported examples under Rh(I)-catalysis. In the case of high oxidation state transition metals, Rh(III)-catalytic complex was found efficient to mediate new pathway to imides using dioxazolones in good yields (up to 97%). Numerous parameters affecting the C-H activation of aldehyde were screened, and the mechanistic investigations were supported by labelling tests. Unfortunately, we observed that some catalytic systems, that are able to achieve aromatic C(sp2)-H bond functionalization with carbon dioxide, were not efficient to afford the carboxylation of aldehydic C(sp2)-H bond. The third chapter disclosed the experimental procedures and the characterization of the new products, notably imides
2
Zhao, Liqin. "Palladium-catalyzed direct arylation via sp² and sp³ C-H activation of hetero(aromatics) and hydrocarbons for C-C bond formation". Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S038/document.
Abstract (sommario):
Au cours de cette thèse, nous nous sommes intéressés à l'activation de liaisons sp² et sp³ C-H catalysée par le palladium pour la préparation d'(hétéro)aryl-aryles et de biaryles. Cette méthode est considérée comme attractive pour l'environnement par rapport aux méthodes classiques, tels que Suzuki, Heck, ou Negishi. Tout d'abord, nous avons décrit que la C2-arylation directe de benzothiophènes peut être effectuée par un catalyseur du palladium en l'absence de ligand phosphine avec une grande sélectivité. Nous avons également démontré qu'il est possible d'activer les positions C2 et C5 de pyrroles pour accéder en une seule étape a des 2,5-diarylpyrroles. Des 2,5-diarylpyrroles non-symétriques ont été formés par arylation séquentielle en C2 suivie par une arylation en C5. Nous avons également étudié la réactivité de polychlorobenzenes pour l'activation de liaisons C-H catalysé au palladium. Nous avons finalement étudié l'activation sp² et sp³ sélective catalysé au palladium de liaisons C-H du guaiazulene. La sélectivité de la réaction dépend du solvant et de la base : C2-arylation (KOAc en éthylbenzène), C3-arylation (KOAc dans le DMAc) et C4-Me arylation (CsOAc/K₂CO₃ dans le DMAc). Grâce à cette méthode, une liaison sp³ C-H peu réactive a été activéeDuring this thesis, we were interested in the sp² and sp³ C-H bond activation catalyzed by palladium catalysts for the preparation of (hetero)aryl-aryls and biaryls. This method is considered as cost effective and environmentally attractive compared to the classical couplings such as Suzuki, Heck, or Negishi. First we described the palladium-catalyzed direct C2-arylation of benzothiophene in the absence of phosphine ligand with high selectivity. We also demonstrated that it is possible to active both C2 and C5 C-H bonds for access to 2,5-diarylated compounds in one step, and also to non-symmetrically substituted 2,5-diarylpyrroles via sequential C2 arylation followed by C5 arylation. We also studied the reactivity of polychlorobenzenes via palladium-catalyzed C-H activation. We finally examined the palladium-catalysed selective sp² and sp³ C-H bond activation of guaiazulene. The selectivity depends on the solvent and base: sp² C2-arylation (KOAc in ethylbenzene), sp² C3-arylation (KOAc in DMAc) and sp³ C4-Me arylation (CsOAc/K₂CO₃ in DMAc). Through this method, a challenging sp³ C-H bond was activated
3
Jadhav, D. "Visible light photoredox catalysis in sp3 C-H activation of t-amines for C-C bond formation reaction". Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2014. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/1948.
4
Obenhuber, Andreas H. [Verfasser]. "Investigation into the chelate assisted activation of non-strained C(sp2)-C(sp2) single bonds using group 8, 9 and 10 transition metal complexes / Andreas H. Obenhuber". München : Verlag Dr. Hut, 2011. http://d-nb.info/1011441535/34.
5
Sofack-Kreutzer, Julien. "Synthèses de carbocycles et d'hétérocycles à cinq chaînons par activation de liaisons c(sp3)-h non activées". Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-00744243.
Abstract (sommario):
La fonctionnalisation de liaisons C-H réputées peu réactives ouvre de nouvelles perspectives en synthèse organique. La catalyse par un métal de transition comme le palladium représente une solution particulièrement efficace à ce problème. Les travaux de thèse présentés dans ce mémoire s'inscrivent dans ce contexte. Dans un premier temps, la réaction étudiée, catalysée par le palladium, a visé à étendre une méthodologie mise au point au laboratoire pour la synthèse de carbocycles et d'hétérocycles à cinq chaînons par activation intramoléculaire de liaisons C(sp3)-H à partir de chlorures d'aryles. Ces derniers sont en effet plus disponibles et moins onéreux que les bromures d'aryle correspondants. Des études d'optimisation ont été effectuées pour la mise au point d'une réaction diastéréosélective et régiosélective. Plusieurs substrats ont été synthétisés pour être ensuite placés dans les conditions optimales de la réaction d'activation C(sp3)-H, et ont conduit à une grande diversité de cycles à cinq chaînons fusionnés. Dans un deuxième temps, nos travaux ont consisté à étendre l'activation C(sp3)-H pallado-catalysée à des précurseurs non aromatiques cycliques ou acycliques. Pour des raisons d'accessibilité, nos études se sont alors portées sur la préparation de bromures vinyliques azotés pouvant conduire après activation C-H à des motifs hexahydroindoles ou pyrrolidines. De nouvelles conditions d'activation CH ont alors été trouvées pour cette famille de substrats, et ont conduit aux hétérocycles cibles de manière diastéréosélective et régiosélective. Après extension de la réaction à divers précurseurs, nous nous sommes intéressés à la synthèse d'un intermédiaire poly-fonctionnalisé permettant d'accéder aux aéruginosines, famille de produits naturels bioactifs.
6
Guyonnet, Mathieu. "Synthèse totale d’alcaloïdes de type dibenzopyrrocoline par arylation C(sp3)-H intramoléculaire". Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10143.
Abstract (sommario):
La fonctionnalisation de liaisons carbone – hydrogène réputées peu réactives ouvre de nouvelles perspectives en synthèse organique. Une stratégie efficace consiste en l'utilisation de métaux de transition comme le palladium. L'activation C-H organométallique a fait l'objet de nombreux développements méthodologiques au cours des dernières décennies, toutefois peu d'applications de ces travaux en synthèse multi-étapes ou totale sont reportées dans la littérature. Les travaux de recherche décrits dans ce mémoire s'inscrivent dans ce contexte. Nous nous sommes intéressés à la famille des alcaloïdes de type dibenzopyrrocoline, une famille de produits naturels structurellement originaux. Au vu des travaux précédemment reportés dans la littérature, l'analyse rétrosynthétique de ces produits nous a conduits à développer dans un premier temps une séquence N-arylation / bromation / arylation C(sp3)-H intramoléculaire de lactames et analogues qui nous a permis d'accéder à diverses indolines tricycliques fusionnées. Dans un deuxième temps, la synthèse du squelette dibenzopyrrocoline a été entreprise à l'aide de la méthodologie séquentielle développée et la difficulté d'accès au précurseur d'arylation C(sp3)-H intramoléculaire a nécessité l'exploration de différentes voies synthétiques, potentiellement prometteuses. Enfin les différents travaux méthodologiques effectués ont mis à jour la faisabilité de l'arylation C(sp3)-H intramoléculaire d'anilines tertiaires, jamais reportée dans la littératureThe direct functionalization of unactivated C-H bonds represents an atom- and stepeconomical alternative to more traditional synthetic methods based on functional group interconversion. Transition-metal catalysis has recently emerged as a powerful tool to functionalize otherwise unreactive C-H bonds. Whereas a lot of methodological studies have been developed in the past decade, few applications of these methodologies in multi-step or total synthesis have been reported in the literature. In this context, we envisioned the total synthesis of dibenzopyrrocoline alkaloids, a family of structurally original natural products, by using intramolecular C(sp3)-H arylation as a key step. This work led us to first develop a N-arylation / bromination / intramolecular C(sp3)-H arylation sequence which allowed us to access diverse fused tricyclic indolines. We next investigated the application of this strategy to the synthesis of the dibenzopyrrocoline motif. The difficulty to access the C(sp3)-H arylation precursor required an exploration of different synthetic pathways, which proved to be potentially promising. Finally the different performed methodological studies showed the feasibility of the intramolecular C(sp3)-H arylation of tertiary anilines, which was never described in the literature
7
Renaudat, Alice. "Fonctionnalisation de liaisons C(sp3)-H non activées catalysées par le palladium". Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00704011.
Abstract (sommario):
La fonctionnalisation de liaisons C-H réputées peu réactives ouvre de nouvelles perspectives en synthèse organique. Une stratégie efficace consiste en l'utilisation d'un métal de transition. Les travaux de thèse présentés dans ce mémoire s'inscrivent dans ce contexte. Dans un premier temps, la réaction étudiée, catalysée par le palladium, vise à étendre une méthodologie mise au point au laboratoire, permettant la synthèse de benzocyclobutènes par activation intramoléculaire de liaisons C(sp3)-H de groupements méthyles benzyliques, à des composés non aromatiques. Plusieurs substrats ont été synthétisés pour être ensuite placés dans les conditions de la réaction d'activation C(sp3)-H, dans le but d'induire la formation du cyclobutène ou du cyclobutane désiré. Le processus n'est pas sélectif et de nombreux produits secondaires sont obtenus par des réactions péricyliques ou par des réarrangements suite à l'ouverture du palladacycle intermédiaire. Dans un deuxième temps, nos travaux ont permis de mettre à jour une nouvelle réaction de fonctionnalisation C(sp3)-H, catalysée par le palladium permettant l'arylation d'esters en position β par un mécanisme original. Les investigations portent sur l'optimisation complète de cette réaction, la compréhension du mécanisme et le développement d'une version énantiosélective prometteuse. Le mécanisme de cette réaction, confirmé par des calculs DFT réalisés en collaboration avec C. Kefalidis et E. Clot, se rapproche formellement de celui observé en α-arylation, puisqu'il repose sur la formation d'un énolate de palladium. La stratégie mise au point permet le couplage, dans des conditions douces, d'esters simples et commerciaux avec des halogénures d'aryles contenant un groupement électronégatif en position ortho, donnant ainsi accès à des intermédiaires de synthèse intéressants tels qu'un analogue de la phénylalanine ou des composés fluorés.
8
Rousseaux, Sophie. "Palladium-Catalyzed C(sp2)-C(sp3) Bond Formation". Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23058.
Abstract (sommario):
Palladium-catalyzed reactions for carbon-carbon bond formation have had a significant impact on the field of organic chemistry in recent decades. Illustrative is the 2010 Nobel Prize, awarded for “palladium-catalyzed cross couplings in organic synthesis”, and the numerous applications of these transformations in industrial settings. This thesis describes recent developments in C(sp2)-C(sp3) bond formation, focusing on alkane arylation reactions and arylative dearomatization transformations. In the first part, our contributions to the development of intramolecular C(sp3)-H arylation reactions from aryl chlorides are described (Chapter 2). The use of catalytic quantities of pivalic acid was found to be crucial to observe the desired reactivity. The reactions are highly chemoselective for arylation at primary aliphatic C-H bonds. Theoretical calculations revealed that C-H bond cleavage is facilitated by the formation of an agostic interaction between the palladium centre and a geminal C-H bond. In the following section, the development of an alkane arylation reaction adjacent to amides and sulfonamides is presented (Chapter 3). The mechanism of C(sp3)-H bond cleavage in alkane arylation reactions is also addressed through an in-depth experimental and theoretical mechanistic study. The isolation and characterization of an intermediate in the catalytic cycle, the evaluation of the roles of both carbonate and pivalate bases in reaction mechanism as well as kinetic studies are reported. Our serendipitous discovery of an arylation reaction at cyclopropane methylene C-H bonds is discussed in Chapter 4. Reaction conditions for the conversion of cyclopropylanilines to quinolines/tetrahydroquinolines via one-pot palladium(0)-catalyzed C(sp3)-H arylation with subsequent oxidation/reduction are described. Initial studies are also presented, which suggest that this transformation is mechanistically unique from other Pd catalyzed cyclopropane ring-opening reactions. Preliminary investigations towards the development of an asymmetric alkane arylation reaction are highlighted in Chapter 5. Both chiral carboxylic acid additives and phosphine ligands have been examined in this context. While high yields and enantiomeric excesses were never observed, encouraging results have been obtained and are supported by recent reports from other research groups. Finally, in part two, the use of Pd(0)-catalysis for the intramolecular arylative dearomatization of phenols is presented (Chapter 7). These reactions generate spirocyclohexadienones bearing all-carbon quaternary centres in good to excellent yields. The nature of the base, although not well understood, appears to be crucial for this transformation. Preliminary results in the development of an enantioselective variant of this transformation demonstrate the influence of catalyst activation on levels of enantiomeric excess.
9
Torkelson, Jeffrey Robert. "C-H bond activation and C-C bond formation at adjacent metals". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ34848.pdf.
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Vastine, Benjamin Alan. "Understanding mechanisms for C-H bond activation". [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2679.
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Wiley, Jack Scott. "C-H bond activation in iridium complexes /". Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/8510.
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Guo, Xiangyu. "Ruthenium-catalyzed C-C bond formation via functional-group directed C-H bond activation". Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110570.
Abstract (sommario):
AbstractRuthenium-Catalyzed C-C Bond Formation via Functional-Group Directed C-H Bond ActivationXiangyu GuoAdvisor: Prof. Chao-Jun LiMcGill UniversityThis thesis is an investigation on the formation of carbon-carbon (C-C) bonds in the presence of ruthenium catalyst.In the first part of this thesis, oxidative dehydrogenative coupling reactions for carbon-carbon (C-C) bond formation are described. A ruthenium-catalyzed dimerization of 2-phenylpyridine derivatives is demonstrated to synthesize biaryls using iron(III) chloride as the terminal oxidant. In addition, the oxidative cross coupling of arenes and cycloalkanes is also illustrated, achieving a unique para-selectivity.In the second part of the thesis, a ruthenium-catalyzed olefination via decarbonylative addition of aldehydes to terminal alkynes is described. Conjugated and isolated C=C bonds can be chemoselectively generated in two catalytic systems starting from aromatic and aliphatic aldehydes. The method provides an alternative synthesis of C=C bonds from direct C-H bond addition to triple bonds.RésuméRuthenium-Catalyzed C-C Bond Formation via Functional-Group Directed C-H Bond ActivationXiangyu GuoSuperviseur: Prof. Chao-Jun LiUniversité McGillCette thèse est le résultat de la recherche sur la formation de liaisons carbone-carbone (C-C), catalysé par le ruthénium. La première partie de cette thèse expose les résultats sur la formation de liaison carbone-carbone (C-C) par la réaction de couplage oxydant par déshydrogénation. La synthèse de composés biaryl par l'utilisation d'un catalyseur de ruthénium a permis la dimérisation des dérivés de la 2-phénylpyridine en présence de chlorure de fer (III) comme oxydant terminal. En outre, l'oxydative cross-coupling entre arènes et cycloalcanes, a montrer une notable, para-sélectivité. La seconde partie de cette thèse, décrit les résultats obtenue sur la réaction d'oléfination decarbonylative entre un aldéhyde et un alcyne vrai, catalyser par le ruthénium. En partant d'aldéhydes aromatiques ou aliphatiques et par l'utilisation de deux systèmes catalytiques, la synthèse chemioselective de double liaison C=C conjuguée ou isolée ont pu être réalisé. Cette réaction fournit ainsi, une intéressante alternative à la synthèse de doubles liaisons C=C par la directe addition de liaison C-H sur une triple liaison.
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Gao, Longhui. "C-H bond activation catalyzed by Ruthenium nanoparticles". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS348/document.
Abstract (sommario):
Les molécules marquées par des isotopes de l’hydrogène possèdent de nombreuses applications dans divers domaines tels que la chimie, la biologie ou en science des matériaux. Dans le domaine de la recherche de nouveaux médicaments, les études liées à la pharmacocinétique nécessitent un accès rapide à des molécules marquées afin de ne pas impacter les coûts et les délais de développement. Le développement de la métabolomique a aussi entrainé une augmentation du besoin en molécules marquées isotopiquement. En effet, les molécules deuterées peuvent être utilisées en tant qu’étalons internes pour la quantification rapide des métabolites présents dans des tissus ou des fluides biologiques. La première partie de cette thèse concerne le développement d’une méthode générale de marquage de motifs de type thioéther dans des molécules complexes à l’aide d’une nouvelle réaction d’échange isotopique (catalysée par des nanoparticules de Ruthénium). D’un point de vue fondamental cette transformation représente le premier exemple de (Csp³)-H activation dirigée par un atome de soufre. En termes d’application, cette nouvelle réaction permet la synthèse rapide d’étalons internes pour la quantification LC-MS/MS et le marquage tritium de molécules complexes. La seconde partie de cette thèse relate le développement d’une nouvelle méthode d’homocouplage de phénylpyridines catalysée par Ru/C. Différents substrats comportant des substituants riches et pauvres en électron ont été couplés avec de bons rendements. Ces dimères ont ensuite été utilisés pour synthétiser de nouveaux complexes de bore dont les propriétés photophysiques ont été étudiées. Dans une troisième partie, la mise au point d’une réaction palladocatalysée permettant d’obtenir des molécules polycycliques contenant un motif de type pyridine est développéeDeuterated and tritiated compounds are widely used in numerous applications in chemistry, biology and material science. In the drug discovery and development process, ADME studies require quick access to labelled molecules, otherwise the drug development costs and timeline are significantly impacted. The rapid development of metabolomics has also increased the need for isotopically labelled compounds. In particular, deuterated molecules are used as internal standards for quantitative LC-MS/MS analysis of metabolites in biological fluids and tissues. In this context, a general method allowing the deuterium and tritium labelling of bioactive thioethers using a HIE reaction is described in the first chapter. From a fundamental point of view, this transformation is the first example of (Csp³)-H activation directed by a sulfur atom. In terms of application, this new reaction has been proved to be useful for the preparation of deuterated LC-MS/MS reference materials and tritiated pharmaceuticals owning high specific activity.In the second chapter of this manuscript, the development of a method allowing the cross-dehydrogenative homocoupling of 2-arylpyridines catalyzed by Ru/C is developed. Various substrates with different substituents were efficiently coupled to give the desired dimers in good yield. In terms of application, a series of pyridine-boron complexes derived from the phenyl pyridine dimers were also synthesized and their photophysical properties were studied.In the third chapter, a regioselective palladium catalyzed intramolecular arylation reaction allowing the synthesis of pyridine containing polycyclic compounds is described
14
Biswas, Achintesh Narayan. "C-H bond activation by transition metal complexes". Thesis, University of North Bengal, 2010. http://hdl.handle.net/123456789/1362.
15
Torigoe, Takeru. "New Molecular Transformations Based on Iridium-Catalyzed Activation of C(sp3)-H Bonds". 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225636.
16
Ebe, Yusuke. "Iridium-Catalyzed Carbon-Carbon Bond Formation Reactions via C-H Bond Activation". 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225417.
17
Ho, Kelvin. "Rapid increase of molecular complexity through C–H and C–C bond activation". Thesis, University of Liverpool, 2014. http://livrepository.liverpool.ac.uk/2006222/.
Abstract (sommario):
The activation of carbon-hydrogen (C–H) and carbon-carbon (C–C) bonds by transition metal catalysts is an attractive strategy to streamline organic synthesis. Herein this manuscript, the two main areas of research are described. Firstly, it was found that a nickel catalyst can promote the insertion of alkynes into the C–C bond of 3-azetidinones and 3-oxetanones to enable quicker access to pyranones and pyridinones in high yields and excellent regioselectivity. Secondly, a rhodium-catalysed pyridine directed C–H bond activation enables the rearrangement of 1,6-heptadienes into bicyclo[2.2.1]heptanes in good yields. Importantly, three stereogenic centres are created with complete diastereocontrol in this atom-efficient reaction. In chapter 1, an overview of the literature on transition metal-catalysed C–C bond activation of four membered rings is described. In chapter 2, our efforts to optimise the catalytic conditions and build the scope of the nickel-catalysed reaction are reported. In chapter 3, the results of the mechanistic investigations of the nickel-catalysed reaction are reported. Finally in chapter 4, a brief overview of the transition metal-catalysed functionalisation of an alkene C–H bond with another alkene is described. Subsequently, the optimisation of the catalytic conditions and the scope of the diastereoselective carbocyclisation of 1,6-heptadienes triggered by rhodium-catalysed activation of an alkene C–H bond are reported.
18
Duin, Marcel Adrianus. "Nucleophilic and electrophilic platinum compounds for C-H bond activation". [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2004. http://dare.uva.nl/document/75218.
19
Black, Stephen Ian. "Synthetic and mechanistic studies related to C-H bond activation". Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/46966.
20
Haffemayer, Benjamin. "Development of novel amine-directed Pd(II)-catalysed sp2 and sp3 C-H bond functionalisation processes". Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607792.
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Coxon, Thomas. "Investigating rhodium-catalysed hydroacylation and carbon-carbon bond activation". Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:26111304-1563-4c18-956e-67636b87983a.
Abstract (sommario):
The work described in this thesis documents the development of new rhodium(I)-catalysed methodologies within two areas of research. The first examines the use of carbonyls as chelating groups in hydroacylation to produce synthetically valuable ketones and enones. The second area explores new carbon-carbon bond activation methodologies. Chapter 1 presents a literature review of the historical development of rhodium-catalysed hydroacylation, with a focus on chelating groups that can currently be used to suppress decarbonylation. A brief review of methodologies that avoid the requirement for a tether is also included. Chapter 2 describes the development of a novel hydroacylation methodology employing carbonyl-based functional groups as tethers on aldehyde substrates. The chapter begins with the optimisation studies for the hydroacylation of β-formyl amides with terminal and internal alkynes, allenes and terminal alkenes, and subsequently explores the substrate scope for each case. The chapter then outlines the investigations undertaken with 1,4-dicarbonyl and 1,5-dicarbonyl systems, N-formyl amides, β-formyl esters and finally β-formyl ketones. A detailed description of the routes undertaken to synthesise each starting material is also presented. Chapter 3 presents a short review surveying the key milestones in the development of carbon-carbon activation methodologies. The chapter begins with a theoretical comparison to carbon-hydrogen activation and a discussion of the unique challenges that are faced. An overview of the major strategies employed to enact these processes is subsequently presented for both strained and unstrained substrates. Chapter 4 outlines the attempts undertaken to develop a novel carbon-carbon bond activation methodology. The work evaluates sulfur-, nitrogen- and alkene-based chelating groups, known to be successful in hydroacylation, in analogous ketone substrates. Chapter 5 discusses the conclusions from this work and the potential for further work. Chapter 6 presents the experimental procedures and data.
22
Holthausen, Michael H., Tayseer Mahdi, Christoph Schlepphorst, Lindsay J. Hounjet, Jan J. Weigand e Douglas W. Stephan. "Frustrated Lewis pair-mediated C–O or C–H bond activation of ethers". Royal Society of Chemistry, 2014. https://tud.qucosa.de/id/qucosa%3A35977.
Abstract (sommario):
Protocols for the FLP-mediated transformation of ethers are presented. Distinct reaction pathways involving either C–O or C–H bond activation occur depending on the application of oxophilic B(C6F5)3 or hydridophilic tritylium ions as the Lewis acid.
23
Li, Bin. "Ruthenium(II) catalyzed C-H bond functionalization and hydrosilylation reactions". Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S114.
Abstract (sommario):
Dans ce travail de recherche, la synthèse de complexes de ruthénium cyclometallés a été effectuée à partir d'imines, 2-phénylpyridine, 2-phényloxazoline, phénylpyrazole, et benzo[h]quinoline par réaction avec [RuCl2(p-cymène)]2 et KOAc via une activation de liaison sp2 C-H. Le système [RuCl2(p-cymène)]2/KOAc/PPh3 est un catalyseur efficace pour réaliser la diarylation d'imines et de 2-phénylpyridine dans l'eau, solvant qui donne de meilleures activités que les solvants organiques. Des amines encombrées ont été préparées par une séquence catalytique activation C-H/arylation/ hydrosilylation d'imines catalysée par [RuCl2(p-cymène)]2. La monoarylation sélective de 2-pyridyl arylcétones, via la formation d'un intermédiaire ruthénacycle à 6 chainons plus difficile à former, est catalysée par l'espèce Ru(O2CC6H4CF3)2(p-cymène) formée in situ. L'alcénylation déhydrogénative oxydante directe d'aryloxazoline par du styrène et des acrylates est catalysée par le système [RuCl2(p-cymène)]2/BNPAH (1,1′-binaphthyl-2,2′- diylhydrogénophosphate) en présence de Cu(OAc)2.H2O utilisé comme oxydant sous air. La réaction tandem oxydation des 2-pyridylméthanols / mono- ou di-α-alkylation sélective de liaisons sp3 C-H de 2-pyridylcétones avec des alcènes fonctionnalisés a été catalysée par le complexe de [RuCl2(p-cymène)]2 en présence de Cu(OAc)2.H2O dans le DCE ou le toluène. Dans la deuxième partie de ce travail, le complexe [RuCl2(p-cymène)]2 a été utilisé efficacement en hydrosilylation catalytique d'imines et d'amides primaires. Nombreuses aldimines et cétimines ont été réduites chémosélectivement en amines correspondantes en utilisant le PMHS comme silane « vert » dans l'éthanol à température ambiante. De plus les amides primaires ont été sélectivement transformés en amines secondaires dans une réaction sans solvantIn this research doctoral thesis, we have shown that imines, 2-phenylpyridine, 2-phenyloxazoline, phenylpyrazole, benzo[h]quinoline led to cyclometallated ruthenium(II) complexes from [RuCl2(p-cymene)]2 and KOAc via sp2 C-H bond activation. [RuCl2(p-cymene)]2 /KOAc/PPh3 is an efficient catalytic system for diarylation of imines and 2-phenyloxazolines in water, which gave higher activity than in organic solvents. Bulky amines were then synthesized through sequential catalytic C-H arylation and hydrosilylation of imines using [RuCl2(p-cymene)]2 catalyst. Challenging selective mono arylation of 2-pyridyl arylketones, leading to six-membered ruthenacycle intermediate, difficult to perform, was achieved with in situ generated Ru(O2CC6H4CF3)2(p-cymene) catalyst. The direct dehydrogenative oxidative alkenylation of aryloxazolines with styrenes and acrylates was catalyzed by [RuCl2(p-cymene)]2/BNPAH (1,1′-binaphthyl-2,2′- diylhydrogenophosphate) catalytic system in the presence of Cu(OAc)2.H2O as an oxidant in air. Tandem catalytic oxidation of 2-pyridylmethanols and selective sp3 C-H (mono or di) α-alkylation of 2-pyridyl ketones with functional alkenes was performed by using [RuCl2(p-cymene)]2 complex in the presence of Cu(OAc)2.H2O in DCE or toluene. In the second part, it is shown that, [RuCl2(p-cymene)]2 is a very efficient catalyst for the hydrosilylation of imines and primary amides. A wide range of aldimines and ketimines were successfully reduced to corresponding amines in high chemoselectivity by using PMHS as greener silane in ethanol at RT. Moreover, challengingly, primary amides could be selectively converted by hydrosilylation to the secondary amines under solvent free conditions
24
Fallon, Brendan. "Cobalt-catalyzed bond activation : C-H functionalization, hydrosilylation and coupling reactions". Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066411/document.
Abstract (sommario):
Dans cette thèse, nous nous concentrerons principalement sur l’utilisation de complexes basse-valence de cobalt bien définis de la famille des RCo(PMe3)4 pour l’activation de divers types de liaisons (C–H, Si–H, C–X). Notre but était de développer un système compétitif par rapport au système bimétallique de Yoshikai, mais aussi par rapport aux systèmes onéreux à base de rhodium. Nous avons démontré avec succès que les complexes isolés Co(PMe3)4 et HCo(PMe3)4 étaient des catalyseurs efficaces pour l’hydroarylation de différents alcynes et alcènes via une activation de liaisons C–H. De plus, nous avons fait une étude mécanistique en couplant des marquages au deutérium et des études de chimie théorique. Nous avons déterminé que la fonctionnalisation de liaisons C–H se faisait selon un mécanisme concerté appelé ‘’Ligand-to-Ligand Hydrogen Transfer’’ (LLHT). A partir de ces études, nous avons pu aussi développer une hydrosilylation hautement régio- et stéréosélective d’alcynes permettant d’utiliser un grand nombre de silanes différents. Nous avons pu au cours de cette étude isoler un nouveau complexe de cobalt(III) bis-hydrure jouant un rôle important dans le mécanisme. Enfin, nous décrivons aussi que ces mêmes complexes de cobalt RCo(PMe3)4 sont capables de catalyser l’homocouplage de bromure et chlorure de benzyle en présence de dimethylzinc. Une étude mécanistique préliminaire suggère que la réaction procède par deux transferts mono-électroniques et que le diméthylzinc permet de régénérer le catalyseurThis thesis has focused on the use of well-defined low-valent cobalt complexes of the family RCo(PMe3)4 for a variety of bond activation (C–H, Si–H, C–X). We aimed to develop a catalytic system that could compete with the previously reported bimetallic systems of Yoshikai and expensive rhodium catalysis. To this end, we successful demonstrated that Co(PMe3)4 and HCo(PMe3)4 are efficient catalysts for the hydroarylation of a broad variety of alkynes and alkenes. In addition, we carried out extensive mechanistic investigations using deuterium labelling experiments and theoretical studies namely DFT. The main finding of these studies was that the C–H bond activation proceeded via a ligand-to-ligand hydrogen transfer mechanism. Following on from this study we then showed that it was possible to carry out the regio- and stereoselective hydrosilylation of internal alkynes with a broad variety of hydrosilanes. During this study we successfully isolated an interesting cobalt(III) intermediate which we believe plays a crucial role in the reaction mechanism. Finally, we report on the ability of these catalysts to efficiently catalyze the homocoupling of benzyl halides in the presence of dimethylzinc. Initial mechanistic investigations suggest that the reaction takes via two single electron transfers and that dimethylzinc act to regenerate the catalyst
25
Pearson, Stephen. "High oxidation state carbene complexes for C-H bond activation catalysis". Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/7570.
Abstract (sommario):
Chapter one is an introduction to the less common coordination and oxidation chemistry of palladium; complexes containing Pd-OR, Pd-NR2 and those in the oxidation states of +IV. An outline of PdII/IV catalysed ligand-directed oxidative functionalisation is also included. Chapter two covers the design and synthesis of a range of tethered N-heterocyclic carbene (NHC) complexes of Pd. In addition, the syntheses of a number of new tethered NHC ligands are described. The use of Density Functional Theory (DFT) to model the complexes in this thesis was explored. Chapter three describes the synthesis and characterisation of PdIV halide complexes. The relevance of these compounds to PdII/IV catalysed ligand-directed oxidative functionalisation is explored. DFT was used to probe the reaction pathway for N-bromosuccinimide and iodobenzene dichloride. Chapter four examines reactions with oxidants used to form C-O and C-C bonds. The reaction pathway for iodobenzene diacetate was investigated using DFT. Chapter five contains experimental details and characterising data for the compounds reported.
26
Chhetri, Satyadeep Singh. "C (Aryl) - H bond activation : isolation, characterization and reactivity of cyclometallates". Thesis, University of North Bengal, 2012. http://hdl.handle.net/123456789/1471.
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Poater, Teixidor Albert. "Isomerism and C-H, C-C, O-O, C-O bond activation studies by transition metals". Doctoral thesis, Universitat de Girona, 2006. http://hdl.handle.net/10803/7939.
Abstract (sommario):
Aquesta tesi és el reflex que de la cooperació entre grups experimentals i grups teòrics s'aconsegueix l'assoliment d'objectius inassolibles de forma individual. A partir de la DFT s'expliquen processos inorgànics i organometàl·lics de gran valor biològic i/o industrial. La tesi està enfocada especialment a l'estudi de complexos mononuclears i binuclears de coure, on té lloc l'activació d'enllaços C-H, C-C, i O-O. L'estudi de complexos octaèdrics de ruteni ha permès dur a terme extensos estudis isomèrics i racionalitzar les propietats espectroscòpiques dels mateixos. A més a més, estudis més puntuals respecte clusters de coure, l'estudi de la reacció de Pawson-Khand, l'estudi d'enllaços Pt-Pt en complexos trimèrics de platí, a més a més de l'estudi de la isomeria de complexos de Ni i Pt.This thesis shows that the cooperation between experimental and theoretical groups gives as a result the achievement of aims impossible working independently. From DFT calculations inorganic and organometallic problems related to great biological and industrial processes can be explained. This thesis is especially focused on the study of mononuclear and binuclear copper complexes, where a C-H, C-C, and O-O bond activation takes place. The study of octahedral ruthenium complexes has allowed carrying out isomeric studies and the rationalization of spectroscopic properties. Furthermore, other little studies related to copper clusters, the Pawson-Khand reaction, Pt-Pt bond interaction in trimer platinum complexes, and isomerism of Ni and Pt complexes.
28
Barday, Manuel. "Rapid access to heterocycles using transition-metal catalysed C-H and C-C bond activation". Thesis, University of Liverpool, 2018. http://livrepository.liverpool.ac.uk/3029020/.
29
Crépin, Damien. "Rhodium-catalysed C-H and C-C bond activation towards the formation of medium-sized rings". Thesis, University of Liverpool, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.569765.
Abstract (sommario):
Rhodium-catalysed hydroacylation is an elegant methodology which affords ketones in an atom-economical fashion. In this manuscript, the rhodium-catalysed intramolecular hydroacylation of aldehyde-tethered alkylidenecyclopropanes, alkylidenecyclobutanes or alkylideneazetidines is described. This rearrangement which includes a first step of carbon-hydrogen bond activation, a hydrometallation step followed by a ring enlargement and a final reductive elimination of the metal catalyst, leads to the formation of cycloheptenones and cyclooctenones in good to excellent yield. In chapter 1, an overview of the literature on rhodium-catalysed hydro acylation is described. In chapter 2, our efforts to optimise the catalytic conditions and build the scope of 7-membered rings are reported while chapter 3 outlines the results of the mechanistic investigations carried out with aldehyde-tethered alkylidenecyclopropanes. The formation of 8-membered rings is described in chapter 4 and chapter 5 is devoted to the study on the regioselectivity of the ring opening of cyclobutane moieties.
30
Berg, Tieme Adriaan van den. "Iron catalyzed oxidation chemistry from C-H bond activation to DNA cleavage /". [S.l. : [Groningen : s.n.] ; University of Groningen] [Host], 2008. http://irs.ub.rug.nl/ppn/315029242.
31
Raghuvanshi, Keshav. "Ruthenium(II)-Catalyzed C-N, C-O and C-C Formations by C-H Activation". Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2017. http://hdl.handle.net/11858/00-1735-0000-002B-7D4C-2.
32
Zhang, Zhuan. "Late Stage Modifications of Phosphines using Transition-Metal-Catalyzed C–H Bond Functionalization". Thesis, Rennes, Ecole nationale supérieure de chimie, 2020. http://www.theses.fr/2020ENCR0067.
Abstract (sommario):
L'objectif principal de cette thèse de doctorat porte sur la préparation de phosphines polyfonctionnelles par diversification tardive de ligands commerciaux. Nous avons développé l'alkylation la liaison C–H en position ortho' des biarylphosphines catalysée par le rhodium(I). Cette nouvelle méthodologie permet d'accéder facilement à une vaste bibliothèque de phosphines multifonctionnelles. Certains de ces ligands modifiés ont surpassé les phosphines disponibles dans le commerce dans la carboxylation des bromures d'aryle catalysée par le palladium avec du dioxyde de carbone en présence d'un catalyseur photoredox. Pour améliorer la diversité des biarylphosphines, nous avons également perfectionné l'alcénylation des liaisons C–H dirigées par l’atome de posphore(III) des (dialkyl)- et (diaryl)biarylphosphines à partir d'alcynes internes. Le [Rh(OAc)(COD)]2 sans chlorure est un meilleur catalyseur que le [RhCl(COD)]2. Les conditions ont été développées pour contrôler la mono- et la difonctionnalisation. Une de ces nouvelles (dialkyl)biarylphosphines bisalcénylées a été utilisée pour la préparation d'un complexe de palladium(II), et certains de ces ligands fonctionnalisés ont surpassé leurs phosphines non fonctionnalisées correspondantes dans l'amidation palladocatalysée de chlorures d'aryle encombrés. Enfin, nous avons également exploré un nouveau protocole pour l'alkylation des liaison C-H de phsophines via la formation des intermédiaires phosphine-ruthénium cyclométallé à 5 ou à 7 chaînons. Ces phosphines fonctionnalisées ont le potentiel d'améliorer les réactions de couplage croisé des (pseudo)halogénures d'aryle encombrésThe main objective of this PhD thesis deals with the preparation of polyfunctional phosphines by late-stage diversification of commercially available ligands. We have developed rhodium(I)-catalyzed ortho’- C–H bond alkylation of biarylphosphines. This new methodology provides a straightforward access to a large library of multifunctionalized phosphines. Some of these modified ligands outperformed commercially available phosphines in the Pd-catalyzed carboxylation of aryl bromides with carbon dioxide in the presence of a photoredox catalyst. To improve the diversity of biarylphosphines, we have also perfected the P(III)-directed C−H bond alkenylation of (dialkyl)- and (diaryl)biarylphosphines using internal alkynes. Chloride-free [Rh(OAc)(COD)]2 acts as a better catalyst than [RhCl(COD)]2. Conditions were developed to control the mono- and difunctionalization. One of these novel bisalkenylated (dialkyl)biarylphosphines was employed for the preparation of a palladium(II) complex, and some of these functionalized ligands outperformed their corresponding unfunctionalized phosphines in Pd-catalyzed amidation of sterically hindered aryl chlorides. Finally, we have also explored a novel protocol C–H bond alkylation of phosphines via 5- or 7- membered ring cyclometallated phosphineruthenium intermediates. These functionalized phosphines have potential to improve crosscoupling reactions of sterically hindered aryl (pseudo)halides
33
Bheeter, Charles Beromeo. "Palladium-catalysed C-H bond activation for simpler access to ArSO₂R derivatives". Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S171.
Abstract (sommario):
Au cours de cette thèse, nous nous sommes intéressés à l'activation de liaisons C-H catalysée par des catalyseurs au palladium pour la préparation de biaryles portant un groupement SO₂R. De très nombreux composés biologiques possèdent une fonction SO₂R. Nous avons donc choisi d'étudier activation de liaisons C-H de ce type de substrat. L'activation de liaisons C-H est considérée comme attractive pour l'environnement par rapport à d'autres types de couplages tels que Suzuki, Stille, ou Negishi. D'abord, nous avons démontré qu'il est possible d'appliquer la méthode d'activation de liaisons C-H pour l'arylation directe de thiophènes portant un substituant SO₂R. Nous avons ensuite établi un système catalysé au palladium pour l'arylation sélective en C2 de dérivés N-tosylpyrrole. Nous avons constaté que le N-tosylpyrrole est plus réactif comparé au pyrrole non protégé. Nous avons également étudié l'arylation directe d'hétéroarènes par des bromobenzènes possédant un substituant SO₂R soit en C2 ou C4 par catalyse au palladium. Cette méthode fournit un accès simple à des dérivés de ArSO₂R. Enfin, nous avons développé la première méthode de déshydrogénation de liaisons sp³ C-H catalysée au palladium de N-alkyl-benzènesulfonamides pour produire des N-alcényle benzènesulfonamidesDuring this Ph.D. period, we were interested in the C-H bonds activation catalysed by palladium catalysts for the preparation of biaryls units bearing SO₂R group. Many biological compounds present a SO₂R function and thus we chose to activate this family of substrates. This method is considered as cost effective and environmentally attractive compared to other types of couplings such as Suzuki, Stille, or Negishi. First, we demonstrated that it is possible to apply C-H bond activation method for the direct arylation of thiophene derivatives bearing a SO₂R substituent. We then established palladium-catalysed system for the selective C2 arylation of N-tosylpyrrole derivatives. We found that N-tosylpyrrole is more reactive than free NH-pyrrole. We also studied the direct arylation of heteroarenes using bromobenzenes bearing SO₂R substituents either at C2 or C4 via palladium-catalysed C-H activation. This method provides a simpler access to substituted SO₂R derivatives. Finally we developed the first palladium-catalysed dehydrogenative sp³ C-H bond functionalization/activation of N-alkyl-benzenesulfonamides to produce N-alkenyl-benzenesulfonamides. The reaction proceeds with easily accessible ligand-free Pd(OAc)₂ catalyst for aryl bromides bearing electron-withdrawing groups or PdCl(C₃H₅)(dppb) catalyst for aryl bromides with electron-donating substituents. We found that the reaction tolerates a variety of substituents both on nitrogen and on the bromobenzene moiety
34
Saba, Sumbal. "Synthesis of unsymmetrical diorganyl chalcogenides by using arylboronic acids or C (sp2)-H bond functionalization of arenes under greener conditions". reponame:Repositório Institucional da UFSC, 2016. https://repositorio.ufsc.br/xmlui/handle/123456789/168202.
Abstract (sommario):
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Química, 2016.Made available in DSpace on 2016-09-20T05:02:32Z (GMT). No. of bitstreams: 1 341356.pdf: 20337282 bytes, checksum: 2c692523891aae34c8c39befe4a17c29 (MD5) Previous issue date: 2016
No presente trabalho desenvolveram-se procedimentos robustos, econômicos e sustentável para a síntese de dicalcogentos de organoíla não simétricos usando uma variedade de ácidos borônicos arílicos substituídos e arenos [O- ou N-] subtituídos. Na primeira parte, desenvolvemos um sistema catalítico oxidativo que combina iodo/DMSO para a síntese de uma grande variedade de dicalcogenetos de diorganoíla não simétricos (S, Se, Te), utilizando vários ácidos borônicos arílicos sob irradiação de micro-ondas. As reações foram realizadas pela mistura de ácidos boronicos com os dicalgenetos desejados, na presença de 10 mol% de iodo, um equiv. ácidos borônicos arílicos II, 0,5 equiv. de vários dicalcogenetos de diorganoíla I e 2 equiv. de DMSO (como oxidante). Os produtos calcogenados desejados III foram obtidos em rendimentos de bons a excelentes. Todas as reações foram realizadas sem a exclusão de ar e umidade a 100 °C durante 10 minutos sob irradiação de microondas. Vários substituintes com diferentes efeitos eletrônicos e estéricos foram tolerados nas condições ótimas de reação. A metodologia desenvolvida demonstrou ser robusta e pode ser facilmente efetuada na escala de 10 mmol, sem qualquer perda significativa de rendimento. A química aqui descrita representa um protocolo livre de solvente e de metal de transição para a preparação de calcogenetos de diorganoíla não simétricos. O escopo da presente metodologia de acoplamento foi estendido usando trifluoroboratos de potássio vinilícos IV como uma alternativa para os ácidos borônicos, utilizando os parâmetros da condição otimizada. A reação de ditelureto e disseleneto de dirganoíla I ocorreu sem problemas e proporcionou a formação dos produtos acoplados correspondentes em rendimentos isolados de 87% e 89%. Considerando a importância dos compostos organocalcogênio, na segunda etapa deste trabalho, desenvolveu-se um método regiosseletivo, rápido e ambientalmente seguro, catalisado por iodo para a síntese de calcogentos de organoíla. Essa metodologia ocorre pela formação de ligações C-Se / C-S via clivagem oxidativa de ligação C (sp2) -H utilizando arenos [O- ou N-] substituídos. Esse processo é realizado pela calcogenação direta de dicalcogenetos de organoíla I com vários arenos VI, catalisados por 20 mol% de iodo na presença de 3 equivalentes de DMSO (como oxidante). Essa metodologia regiosseletiva, sob irradiação de micro-ondas, permitiu obter os produtos desejados funcionalizados com um substituinte organocalcogenoíla, em 10 min, em bons rendimentos. Outras vantagens desse método são: condições livres de solvente e metal de transição; procedimento experimental sem a exclusão de ar e umidade. A reação também foi efetuada em escala de 10 mmol sem perda significativa de rendimento. Além disso, por este protocolo, foi possível funcionalizar heteroarenos biologicamente importantes contendo S/Se, tais como: pirimidinas, piridinas e tiazóis. A versatilidade da metodologia desenvolvida permitiu ainda a utilização de tiofenol VIII e hidrazidas de sulfonila VIII como agentes sulfenilação e N,N-dimetilanilina IX alternativos, levando-se o produto tiolado X desejados em bom rendimentos, em um tempo de reação curto usando irradiação de micro-ondas.
Abstract : In the present work we developed robust, economical and greener procedures for the synthesis of unsymmetrical diorganyl chalcogenides by using various substituted arylboronic acids and [O or N]- containing arenes. In the first part, we developed Iodine/DMSO catalyzed oxidative system for the synthesis of a variety of unsymmetrical diorganyl chalcogenides (S, Se, Te) using various arylboronic acids under microwave irradiations. The desired chalcogenated products III were obtained in good to excellent yields in the presence of 10 mol% of iodine, one equiv. of arylboronic acids II, half equiv. of various diorganyl dichalcogenides I and 2 equiv. of DMSO (as an oxidant). All the reactions were performed without the exclusion of air and moisture at 100 0C for 10 min under microwave irradiation. Various substituents with different electronic and steric effects tolerated in the optimized reaction conditions. The developed methodology was shown to be robust and could easily be scaled-up without any significant loss of yield. The chemistry described herein represents a transition metal and solvent free method for the preparation of unsymmetrical diorganyl chalcogenides. We were also successful in scaling up the reaction in up to 10 mmol. The scope of this coupling methodology was extended by using potassium vinyltrifluoroborate IV as an alternative to boronic acid in these tellurylation and selenylation reactions by applying the optimal reaction parameters. The reaction of ditelluride and diselenide I proceeded smoothly and afforded the corresponding coupled products V in 87% and 89% isolated yield. Considering the importance of diorganyl chalcogenides, we developed a regioselective, rapid and greener iodine-catalyzed method for the synthesis of diorganyl chalcogenides through oxidative C Se/C S formation via direct C(sp2)-H bond cleavage using [O or N]-containing arenes. In this work, we reported the synthesis of unsymmetrical diorganyl chalcogenides VII via direct chalcogenation reactions between dichalcogenides I and various arenes VI catalyzed by 20 mol% of iodine in the presence of 3 equiv. of DMSO (as an oxidant). This regioselective methodology allowed us to obtain desired chalcogenated product in good to excellent yields under transition metal and solvent-free conditions, without the exclusion of air and moisture, applying microwave irradiations for 10 min. The reaction was also scaled-up to 10 mmol. Additionally, by this protocol, we were able to access biologically important Se/S containing heteroarenes, such as, pyrimidines, pyridines, thiazole. The versatility of the developed methodology was observed by using thiophenol VIII and sulfonyl hydrazides VIII as another sulfenylating agents and N,N-dimethylaniline IX, affording the desired sulfonated product X in very good yield, in a short reaction time using MW irradiation.
35
Carreon-Macedo, Jose-Luis. "Computational studies of spin-forbidden organometallic chemistry : ligand binding and C-H bond activation". Thesis, University of Bristol, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432972.
36
Parveen, Riffat. "Computational Studies of C-H Bond Activation and Ethylene Polymerization Using Transition Metal Complexes". Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505131/.
Abstract (sommario):
This work discusses the C-H bond activation by transition metal complexes using various computational methods. First, we performed a DFT study of oxidative addition of methane to Ta(OC2H4)3A (where A may act as an ancillary ligand) to understand how A may affect the propensity of the complex to undergo oxidative addition. Among the A groups studied, they can be a Lewis acid (B or Al), a saturated, electron-precise moiety (CH or SiH), a σ-donor (N), or a σ-donor/π-acid (P). By varying A, we seek to understand how changing the electronic properties of A can affect the kinetics and thermodynamics of methane C–H activation by these complexes. For all A, the TS with H trans to A is favored kinetically over TS with CH3 trans to A. Upon moving from electron-deficient to electron-rich moieties (P and N), the computed C–H activation barrier for the kinetic product decreases significantly. Thus, changing A greatly influences the barrier for methane C–H oxidative addition by these complexes. Secondly, a computational study of oxidative addition (OA) of methane to M(OC2H4)3A (M = Ta, Re and A = ancillary ligand) was carried out using various computational methods. The purpose of this study was to understand how variation in A and M affects the kinetics and thermodynamics of OA. Results obtained from MP2 calculations revealed that for OA of CH4 to Re(OC2H4)3A, the order of ΔG‡ for a choice of ancillary ligand is B > Al > SiH > CH > N > P. Single point calculations for ΔG‡ obtained with CCSD(T) showed excellent agreement with those computed with MP2 methods. MCSCF calculations indicated that oxidative addition transition states are well described by a single electronic configuration, giving further confidence in the MP2 approach used for geometry optimization and ΔG‡ determination, and that the transition states are more electronically similar to the reactant than the product. Thirdly, a computational study of olefin polymerization has been performed on 51 zirconocene catalysts. The catalysts can be categorized into three classes according to the supporting ligand framework: Class I - Cp2ZrCl2 (ten catalysts), Class II - CpIndZrCl2 (thirty-eight catalysts), and Class III - Ind2ZrCl2 (three catalysts), Cp = η5-cyclopentaidenyl, Ind = η5-indenyl. Detailed reaction pathways, including chain propagation and chain termination steps, are modeled for ethylene polymerization using Class II catalysts. Optimized structures for reaction coordinates indicated the presence of α-agostic interactions in the transition states (TSs) for both the 1st and 2nd ethylene insertions as well as in the ethylene π-complex of the Zr-nPr cation. However, β-agostic interactions predominate in the cationic n-propyl and n-pentyl intermediates. The calculated relative Gibbs free energies show that the TS for insertion of ethylene into the Zr-CH3+ bond is the highest point on the computed reaction coordinates. This study, in concert with previous work, suggests that the type of ring attached to Zr (Cp vs. Ind) affects the reaction kinetics and thermodynamics less significantly than the type of substituents attached to the Cp and indenyl rings, and that substituent effects are even greater than those arising from changing the metal (Zr vs. Hf)
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Ohta, Takehiro. "Studies on C-H Bond Activation by Dinuclear Iron and Copper Enzyme Model Complexes". Kyoto University, 2000. http://hdl.handle.net/2433/180931.
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Tanji, Yutaka. "Steric Effect of Carboxylate Ligands on Pd-Catalyzed C-H Bond Arylation Reactions". Kyoto University, 2020. http://hdl.handle.net/2433/253293.
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Pahls, Dale R. "Pathways for C—H Activation and Functionalization by Group 9 Metals". Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc801909/.
Abstract (sommario):
As fossil fuel resources become more and more scarce, attention has been turned to alternative sources of fuels and energy. One promising prospect is the conversion of methane (natural gas) to methanol, which requires an initial activation of a C-H bond and subsequent formation of a C-O bond. The most well studied methodologies for both C-H activation and C-O bond formation involve oxidation of the metal center. Metal complexes with facile access to oxidation states separated by four charge units, required for two subsequent oxidations, are rare. Non-oxidative methods to perform C-H bond activation or C-O bond formation must be pursued in order for methane to methanol to become a viable strategy. In this dissertation studies on redox and non-redox methods for both C-H activation and C-O bond formation are discussed. In the early chapters C-O bond formation in the form of reductive functionalization is modeled. Polypyridine ligated rhodium complexes were studied computationally to determine the properties that would promote reductive functionalization. These principles were then tested by designing an experimental complex that could form C-O bonds. This complex was then shown to also work in acidic media, a critical aspect for product stabilization. In the later chapters, non-oxidative C-H activation is discussed with Ir complexes. Both sigma bond metathesis and concerted metalation deprotonation were investigated. For the former, the mechanism for an experimentally known complex was elucidated and for the latter the controlling factors for a proposed catalyst were explored.
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Prades, Ferrer Amparo. "NHC-based multifunctional catalysts of Ru, Ir and Rh in C-H bond activation processes". Doctoral thesis, Universitat Jaume I, 2012. http://hdl.handle.net/10803/669163.
Abstract (sommario):
During the last decade, our group of research has developed new synthetic strategies for the preparation of NHC-based homogeneous catalysts with novel stereoelectronic properties. Within this context, this work is focused on the synthesis and characterization of new metallic complexes containing different N-heterocyclic carbene ligands, the study of their reactivity and the exploration of their catalytic properties.
A set of simple `Ru(¿6-arene)(NHC)¿ and `IrCp*(NHC) complexes with different NHC ligands (imidazolylidene, pyrazolylidene and triazolylidene) have been prepared.
The new Ru(II) and Ir(III) complexes have been tested in several catalytic C-H bond activation processes, especially regarding reactions through a borrowing-hydrogen mechanism and functionalization of arenes. The main goal is to perform the catalytic reactions under the `greenest¿ possible conditions, thus using non-toxic solvents under the highest atom-economic conditions and minimum waste of energy.
Two different classes of bis-NHC ligands coordinated to Ir(I) and Rh(I) metal centers have been described in this chapter. The first methodology used provides an alternative to the use of the traditional azolium salts. The double C(sp3)-H2 dehydrogenation of a saturated heterocycle is a novel and interesting way to obtain complexes containing different architectures.
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Esswein, Arthur J. "Late transition metal bimetallics for photocatalytic hydrogen production, M-X and C-H bond activation". Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40970.
Abstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2007.Vita.
Includes bibliographical references.
Broadly defined this thesis has focused on the design and study of molecular catalysts that engender multi-electron reactions and photoreactions on small molecule substrates relevant to solar energy conversion. Specifically the molecular design elements employed have focused on bimetallic complexes of late transition metals that exhibit an unusual two-electron mixed valence ground state. Initial studies focused on the mechanistic elucidation of the reported photocatalytic production of hydrogen from homogeneous hydrohalic acid solution using a two-electron mixed valence dirhodium complex. Studies aimed at understanding and improving the photochemical quantum efficiency for challenging M-X (X = CI, Br-) bond photoactivations were undertaken by incorporating gold into a heterobimetallic rhodium-gold construct. Additionally the organometallic reactivity of two-electron mixed valence diiridium cores was explored with a specific emphasis on C-H bond activations in order to extend the cooperative bimetallic reactivity observed in the dirhodium systems beyond HX and H2 substrates to alkanes and arenes.
by Arthur J. Esswein.
Ph.D.
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Milani, Jessica. "The effect of fluorine substituents on intramolecular C-H bond activation reactions at transition metals". Thesis, University of York, 2016. http://etheses.whiterose.ac.uk/13690/.
Abstract (sommario):
This thesis describes an investigation into the effects of fluorine substituents on the regioselectivity of intramolecular C–H activation reactions at different transition metals, including Pd, Ir, Rh and Ru. A range of mono- and di-fluorinated N,N-dimethylbenzylamines were synthesised initially and their behaviour towards cyclometallation at Pd was studied (Chapter 2), revealing an unprecedented difference in the regioselectivity of the C–H activation between the formation of acetate- and chloro-bridged palladacycles. The spectroscopic and crystallographic properties of all of these palladacycles are described and analysed in detail. Acetate-bridged palladacycles present a “clam-shell” structure, which shows a dramatic variation with the number and the position of the fluorine atoms on the aromatic ring of the ligand. Conversely the planar chloride-bridged palladacycles do not show any structural variation. Biological assays have been performed on two of the fluorinated amino-derived palladacycles against ovarian cancer cells, revealing promising activity. A series of fluorinated diphenylbenzylphosphines and their corresponding chloride-bridged phosphapalladacycles have also been synthesised (Chapter 3), and a similar regioselectivity observed to that seen for the corresponding amino-derived palladacycles. Various successful attempts at cyclometallation reactions using the fluorinated amines as substrates at Rh, Ir and Ru demonstrate a preference for C–H activation ortho to fluorine (Chapter 4). Finally the synthesis of a novel pentafluorobenzyl phosphine, and some preliminary work towards C–F activation reactions using this substrate at Pt is described (Chapter 5).
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Roudesly, Fares. "Fonctionnalisation C-H dirigée d'hétérocycles azotés". Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS354.
Abstract (sommario):
Ce travail de thèse a apporté sa contribution et de nouvelles connaissances dans le domaine de l’activation / fonctionnalisation C-H de noyaux azotés de type pyridine et pyrrole. D’abord, nous avons développé une méthode permettant l’allylation et l’oléfination régiosélective d’azines N-oxyde en utilisant un complexe de Pd(0) formé in situ. Le champ d’application de cette réactivité a ensuite été étudié. Des études expérimentales et des calculs DFT nous ont permis de proposer un mécanisme pour les étapes d’allylation et d’isomérisation. Nous proposons que l’étape d’activation C-H est l’étape cinétiquement déterminante du cycle catalytique et se fait selon un mécanisme de déprotonation/palladation par sphère externe. Ensuite, nous nous sommes intéressés à l’application de la réaction de Murai aux dérivés du 2- pyrrole carboxaldéhyde en utilisant un complexe de Ru(0). L’utilisation du monoxyde de carbone sous pression atmosphérique nous a permis d’obtenir les produits d’acylation en présence de différents vinylsilanes et styrènes. L’application de cette réactivité à d’autres dérivés du 2-pyrrole carboxaldéhyde est en cours d’étude au laboratoireThis thesis work has brought its contribution the field of C-H activation / functionalization of nitrogenous containing rings as pyridine and pyrrole. First, we developed a strategy for a Pd- catalyzed regioselective allylation and alkenylation of azine N-oxides. The scope of this reactivity has been studied. Experimental studies and DFT calculations allowed us to propose a mechanism for the allylation and isomerization steps. We propose that the C-H activation step is the rate determining step of the catalytic cycle, and that it takes place through an outer sphere deprotonation / palladation mechanism. Next, we applied the Murai reaction to 2-pyrrole- carboxaldehyde derivatives using a Ru(0) complex. Under an atmospheric pressure of carbon monoxide, we could obtain the acylated products in the presence of various vinylsilanes and styrenes. The application of this reactivity to other 2-pyrrole carboxaldehyde derivatives is under study in the laboratory
44
Wu, Guanmin. "Synthesis, characterization, and kinetics of isomerization, C-H and P-C bond activation for unsaturated diphosphine-coordinated triosmium carbonyl clusters". Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc6037/.
Abstract (sommario):
Substitution of MeCN ligands in the activated cluster Os3(CO)10(MeCN)2 by the unsaturated diphosphine ligands (Z)-Ph2PCH=CHPPh2 (cDPPEn) or 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) proceeds rapidly at room temperature to furnish the ligand-bridged cluster 1,2-Os3(CO)10(P-P) (P-P represents cDPPEn or bpcd). Heating 1,2-Os3(CO)10(P-P) leads to the formation of the thermodynamically more stable chelating isomer 1,1-Os3(CO)10(P-P). Each compound of Os3(CO)10(P-P) has been characterized by x-ray diffraction, IR, 31P NMR and 1H NMR. Ligand isomerization kinetics have been investigated by UV-VIS and 31P NMR (for cDPPEn) or 1H NMR (for bpcd) spectroscopies. The isomerization mechanism is discussed based on the activation parameters and CO inhibition (for cDPPEn) or ligand trapping experiments (for bpcd). Thermolysis of 1,1-Os3(CO)10(bpcd) in refluxing toluene gives the hydrido cluster HOs3(CO)9[μ-(PPh2)C=C{PPh(C6H4)}C(O)CH2C(O)] and the benzyne cluster HOs3(CO)8(μ3-C6H4)[μ2,η1-PPhC=C(PPh2)C(O)CH2C(O)]. Photolysis of 1,1-Os3(CO)10(bpcd) using near UV light affords HOs3(CO)9[μ-(PPh2)C=C{PPh(C6H4)}C(O)CH2C(O)] as the sole product. HOs3(CO)8(μ3-C6H4)[μ2,η1-PPhC=C(PPh2)C(O)CH2C(O)] has been characterized in solution by IR and NMR spectroscopies. Furthermore its molecular structure has been determined by X-ray crystallography. Reversible C-H bond formation in HOs3(CO)9[μ-(PPh2)C=C{PPh(C6H4)}C(O)CH2C(O)] is demonstrated by ligand trapping studies to give 1,1-Os3(CO)9L(bpcd) (where L = CO, phosphine) via the unsaturated intermediate 1,1-Os3(CO)9(bpcd). The kinetics for reductive coupling in HOs3(CO)9[γ-(PPh2)C=C{PPh(C6H4)}C(O)CH2C(O)] and DOs3(CO)9[μ-(PPh2-d10)C=C{P(Ph-d5)(C6D4)}C(O)CH2C(O)] in the presence of PPh3 give rise to a kH/kD value of 0.88, whose magnitude supports the existence of a preequilibrium involving the hydride(deuteride) cluster and a transient arene-bound Os3 species that precedes the rate-limiting formation of 1,1-Os3(CO)9(bpcd). Strong proof for the proposed hydride(deuteride)/arene preequilibrium has been obtained from photochemical studies employing the isotopically labeled cluster 1,1-Os3(CO)10(bpcd-d4ortho), whose bpcd phenyl groups each contain one ortho hydrogen and deuterium atom. Equilibrium and kinetic isotope effects in the orthometallation step has been determined by 1H NMR in photochemical studies. Kinetics for the transformation from HOs3(CO)9[μ-(PPh2)C=C{PPh(C6H4)}C(O)CH2C(O)] to HOs3(CO)8(μ3-C6H4)[μ2,η1-PPhC=C(PPh2)C(O)CH2C(O)] has been studied by UV-VIS spectroscopy for which the mechanism is discussed.
45
Balzarek, Christoph. "Reactivity and mechanisms in aqueous organometallic chemistry : C-H bond activation in water catalyzed by molybdocenes /". [Eugene, Or. : University of Oregon Library System], 2000. http://libweb.uoregon.edu/UOTheses/2000/balzarekc00.pdf.
46
Balzarek, Christoph 1972. "Reactivity and mechanisms in aqueous organometallic chemistry: C-H bond activation in water catalyzed by molybdocenes". Thesis, University of Oregon, 2000. http://hdl.handle.net/1794/142.
Abstract (sommario):
Adviser: Kenneth M. Doxsee.
xvii, 167 p.A print copy of this title is available through the UO Libraries under the call number: SCIENCE QD412.M7 B35 2000
The chemistry of three organometallic systems in water was studied with the goal of understanding more fully the reactivity of organometallic complexes in aqueous environments. Molybdocene complexes were found to catalyze C-H bond activation reactions in water. The catalytically active solutions were prepared from the molybdocene dimer [Cp
47
Cai, Yingxiao. "Cobalt-catalyzed carbon-carbon bond formation by activation of carbon-halogen or carbon-hydrogen bonds". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX039/document.
Abstract (sommario):
Ce travail de thèse présente le développement de nouvelles réactions de formation de liaisons carbone-carbone. Le premier chapitre décrit la cyanation d’arylzinciques par catalyse au cobalt à partir d’une source non toxique et bénigne, le N-cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS), et conduit à de bons rendements en benzonitriles correspondants. Dans cette réaction, le cobalt sert de catalyseur non seulement pour la formation des arylzinciques mais aussi pour la formation de liaisons C-CN. Les groupements fonctionnels, cétone et nitrile, sont permis lorsque le complexe de cobalt associé au ligand bipyridine est utilisé. Le deuxième chapitre porte sur l’homocouplage Csp3-Csp3. Un simple halogénure de cobalt permet de catalyser la dimérisation des halogénures d’alkyles et des acétates d’allyles avec de bons à d’excellents rendements. L’ajout d’iodure de sodium permet d’étendre cette réaction aux chlorures et tosylates d’alkyles. Le couplage croisé entre 2 halogénures d’alkyle différents a également été testé mais les conditions doivent être optimisées. Dans le troisième chapitre, le couplage croisé catalysé au cobalt entre des bromures vinyliques et des chlorures benzyliques est présenté. Des halogénures de vinyles et de benzyles porteurs de groupements electrodonneurs ou electroattrateurs peuvent ainsi être couplés efficacement avec rétention de la configuration de la double liaison. Un mécanisme radicalaire semble être impliqué. Enfin, le dernier chapitre décrit l’arylation d’une 2-phenylpyridine avec un arylzincique par catalyse au cobalt par activation d’une liaison C-H et conduit à de premiers résultats encourageantsThis thesis presents the development of cobalt-catalyzed carbon-carbon bonds formation. The first chapter describes a novel cobalt-catalyzed electrophilic cyanation of arylzinc species, employing benign and non-toxic N-cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS) as the cyano source. In this reaction, cobalt catalyzes both the formation of arylzinc species and the cyanation reaction. Various benzonitriles are synthesized affording good to excellent yields. Using cobalt-bipyridine complexes instead of CoBr2, ketone and nitrile groups can be tolerated. The second chapter reports cobalt-catalyzed Csp3-Csp3 homocoupling reaction. A simple catalytic system could deliver dimers of a number of alkyl halides/pseudohalides and allylic acetates. Sodium iodide is crucial for the homocoupling of unactivated alkyl chlorides and tosylates. This method is extended to alkyl-alkyl cross-coupling; however, the conditions still need to be optimized. The third chapter describes a cobalt-catalyzed vinyl-benzyl cross-coupling. A variety of functionalized vinyl bromides and benzyl chlorides are efficiently coupled under mild conditions in good to excellent yields, with retention of Z/E configuration. A few mechanistic experiments indicate a single electron transfer involved. The last chapter discusses the progress on the cobalt-catalyzed arylation of 2-phenylpyridine with an arylzinc species by C-H activation and promising results are obtained
48
Wu, Guanmin Richmond Michael G. "Synthesis characterization, and kinetics of isomerization, C-H and P-C bond activation for unsaturated diphosphine-coordinated triosmium carbonyl clusters". [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-6037.
49
Hanson, Susan Kloek. "Synthesis and reactivity studies of late transition metal complexes relevant to C-H bond activation and functionalization /". Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8631.
50
Geng, Caiyun [Verfasser]. "Theoretical Study of C-H Bond Activation by Mononuclear and Dinuclear High-Valent Iron Complexes / Caiyun Geng". Bonn : Universitäts- und Landesbibliothek Bonn, 2012. http://d-nb.info/1044082798/34.