To see the other types of publications on this topic, follow the link: H bond activation.
Dissertations / Theses on the topic 'H bond activation'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'H bond activation.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
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.
Full text
2
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.
Full text
3
Gao, Longhui. "C-H bond activation catalyzed by Ruthenium nanoparticles." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS348/document.
Full textAbstract:
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
4
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.
Full text
5
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.
Full text
6
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.
Full textAbstract:
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.
7
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.
Full text
8
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.
Full text
9
Nako, Adi Edmund. "E-H bond activation by d⁰ and d¹⁰ metal centres." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/44041.
Full textAbstract:
In recent years there has been a drive to study the catalytic dehydrocoupling of various protic and hydridic partners that contain E-H bonds (E = C, N, P, B, Si, Sn). This is in part due to the high atom-efficiency of these reactions as well as their ability to release dihydrogen in a controlled and potentially reversible manner. Transition metal complexes have historically been employed as catalysts for these reactions. Nevertheless, in recent years there has been growing interest in using complexes of the rare earth and main group metals to the same end. For these redox reluctant metals, the lack of multiple stable oxidation states makes σ-bond metathesis the predominant mechanistic step. This contrasts with the common two-electron and one-electron pathways often observed for transition metals. A diverse selection of mechanistic pathways have emerged with complementary activities and selectivities often reported for transition metal and non-transition metal systems. This thesis describes the activation of various E-H (E = C, Si, N, Al, Zn) bonds by do and d10 metal centres in both catalytic and stoichiometric regimes. The [Y{N(SiMe3)2}3] catalysed C-H silylation of triphenylphosphonium methylide with phenylsilane to give Ph3PCHSiH2Ph is reported. This is the first known example of C-H silylation of an ylide, and was found to be highly dependent on the nature of the pre-catalyst. Whilst exploring the reaction chemistry of the same yttrium complex, the first known example of the catalytic dehydrocoupling of Al-H/N-H bonds was discovered. This latter reaction offers a new synthetic route to form Al-N σ-bonds from sterically hindered alane and amine partners. The yttrium mediated dehydrocoupling of Si-H/N-H bonds is also documented with an emphasis on the potential for ligand acceleration of catalysis by a cyclometalated phosphonium ylide complex. As part of these studies, the synthesis of a series of structurally diverse aluminium hydride complexes is discussed. These complexes were not only investigated in the aforementioned dehydrocoupling reaction, but also as ligands for transition metals in their own right. The coordination of both Al-H and related Zn-H σ-bonds to copper(I) was observed in both solution and the solid state and this interaction was characterised by a number of spectroscopic techniques.
10
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.
Full textAbstract:
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.
11
Li, Bin. "Ruthenium(II) catalyzed C-H bond functionalization and hydrosilylation reactions." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S114.
Full textAbstract:
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
12
Fallon, Brendan. "Cobalt-catalyzed bond activation : C-H functionalization, hydrosilylation and coupling reactions." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066411/document.
Full textAbstract:
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
13
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.
Full textAbstract:
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
14
Pearson, Stephen. "High oxidation state carbene complexes for C-H bond activation catalysis." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/7570.
Full textAbstract:
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.
15
Abdalla, Joseph. "Investigations of E-H bond activation processes involving aluminium and gallium." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:ba3a0d95-4993-498b-8b15-e93da9a42aa3.
Full textAbstract:
This thesis examines the interaction of hydrides of the group 13 metals aluminium and gallium with transition metal centres. Furthermore, a gallium-based system is developed which activates a wide range of E-H bonds, with the product of H2 activation found to act as a catalyst for the reduction of CO2 to a methanol derivative. Chapter 3 details the synthesis of a number of alane and gallane adducts of expanded-ring N-heterocyclic carbene (NHC) ligands, which are more strongly Ï-donating and sterically shielding analogues of classical NHCs. These NHC adducts are found to be apposite for the formation of Ï-alane and Ï-gallane complexes at group 6 metal carbonyl fragments, which has allowed the characterisation of the first κ2 Ï-gallane complexes. The attempted formation of a terminally coordinated κ3 Ï-alane complex leads instead to the isolation of a novel dinuclear cluster featuring both μ:κ1,κ1 and μ:κ2,κ2 coordination to Mo(CO)3 units. The work presented in Chapter 4 probes the interaction of the β-diketiminate stabilised gallane Dipp2NacNacGaH2 with transition metal carbonyls. Far from simply mimicking the chemistry of the alane congener Dipp2NacNacAlH2, which forms simple κ1 and κ2 Ï-alane complexes, the gallane shows a marked propensity towards dehydrogenation and formation of direct M-Ga(I) bonds. This represents a rare mode of reactivity among group 13 hydrides, being unprecedented beyond boron chemistry, and provides a new route to M-Ga bond formation. Experimental and computational investigations of the mechanism suggest that initial Ga-H oxidative addition is facile, and is generally followed by rate-limiting loss of H2. The reaction of Dipp2NacNacAlH2 with Co2(CO)2 is shown to yield an unusual alane complex which displays an unprecedented degree of Al-H activation in a Ï-alane complex. Chapter 5 represents an extension of the work described in Chapter 5, investigating the interaction of Dipp2NacNacMH2 (M = Al, Ga) with cationic group 9 transition metal fragments supported by ancillary phosphine ligands. While attempts to isolate unsupported, cationic Ï-alane complexes prove unsuccessful, Dipp2NacNacGaH2 readily binds to cationic rhodium and iridium centres, forming the first cationic Ï-gallane complexes as well as cationic gallylene complexes resulting from complete Ga-H oxidative addition. The extent of Ga-H bond activation is shown to be markedly dependent on the nature of the phosphine co-ligands. In particular, a series of rhodium complexes is reported which represents snapshots of the oxidative addition process, from a Rh(I) Ï-gallane complex to a Rh(III) gallylene dihydride, with two further complexes which are on the cusp of these two oxidation states. Described in Chapter 6 are the synthesis and reactivity studies of an ambiphilic system, Dipp2NacNacâ²Ga(tBu), featuring a three-coordinate gallium centre supported by a deprotonated NacNac ligand. The combination of this electrophilic gallium centre with the highly nucleophilic exocyclic alkene functionality facilitates the cooperative activation of protic, hydridic and apolar E-H bonds. Accordingly, molecules including H2, NH3, H2S and SiH4 may be cleaved under mild conditions. Moreover, the hydride product of H2 activation is shown to be a competent catalyst in conjunction with HBpin for the reduction of CO2 to the methanol derivative MeOBpin.
16
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.
Full textAbstract:
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
17
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.
Full text
18
Bheeter, Charles Beromeo. "Palladium-catalysed C-H bond activation for simpler access to ArSO₂R derivatives." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S171.
Full textAbstract:
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
19
Holthausen, Michael H., Tayseer Mahdi, Christoph Schlepphorst, Lindsay J. Hounjet, Jan J. Weigand, and 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.
Full textAbstract:
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.
20
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/.
Full textAbstract:
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.
21
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.
Full text
22
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/.
Full textAbstract:
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)
23
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.
Full text
24
Tanji, Yutaka. "Steric Effect of Carboxylate Ligands on Pd-Catalyzed C-H Bond Arylation Reactions." Kyoto University, 2020. http://hdl.handle.net/2433/253293.
Full text
25
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/.
Full textAbstract:
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.
26
So, Sonia. "Boronate Urea Activation of Nitro Compounds." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1395764122.
Full text
27
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.
Full textAbstract:
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.
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/.
Full text
29
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.
Full textAbstract:
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.
30
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/.
Full textAbstract:
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).
31
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.
Full textAbstract:
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.
32
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.
Full textAbstract:
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.
33
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.
Full text
34
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.
Full textAbstract:
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
35
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.
Full textAbstract:
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
36
Yuan, Kedong. "Palladium-catalyzed sp² C-H bond functionalization : construction of photoswitches and desulfitative cross-couplings." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S136/document.
Full textAbstract:
Au cours de cette thèse, nous nous sommes intéressés à la synthèse de photo-interrupteurs organiques [DAE, di(hétéro)arylethenes] via activation de liaisons sp² C-H d'hétéroaromatiques catalysées par le palladium. Le système catalytique pour l'arylation directe précédemment établi, Pd(OAc)₂/KOAc/DMAc, s'est montré adapté aux nouvelles transformations souhaitées. Cette méthode permet l'accès direct à une grande variété de molécules photo-commutable en peu d'étapes. En outre, concernant le développement de nouvelles procédures de fonctionnalisation de liaisons C-H d'hétéroaromatiques, nous avons constaté que le système catalytique Pd(CH₃CN)₂Cl2/Li₂CO₃/dioxane, pour le couplage de thiophènes avec des chlorures d'arylsulfonyle conduit à des thiophènes β-arylés. Ce nouveau système catalytique peut également être utilisé dans une réaction d'addition conjuguée, en utilisant des énones et des chlorures d'arylsulfonyle en tant que partenaires de couplage. Enfin, nous avons décrit la formation de 4-aryl-1,2,3,4-tetrahydroquinolines via Heck/sp² C-H activation co-catalysée par PdCl₂/CuBrDuring this thesis, we were interested in the synthesis of organic photo-switches [DAE, di(hetero)arylethenes] via palladium catalyzed sp2 C-H bond activation of heteroaromatics. The previously established catalysts system for direct arylation, Pd(OAc)₂/KOAc/DMA, was found to be suitable for the new desired transformations. This method allows the straightforward access to a wide variety of useful photo-switchable molecules in a few steps. Moreover, during the course of further developments of C-H bond functionalization of heteroaromatics, we found that a phosphine free catalytic system, Pd(CH₃CN)₂Cl2/Li ₂CO₃/dioxane, promotes the coupling of thiophenes and arylsulfonyl chlorides to afford unexpected β-arylated products. This new catalytic system can also be utilized in conjugate addition reaction by using enones and arylsulfonyl chlorides as coupling partners. Finally, we describe PdCl2/CuBr co-catalyzed formation of 4-aryl-1,2,3,4-tetrahydroquinolines via cascade desulfitative Heck/sp² C-H activation sequence
37
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.
Full text
38
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.
Full text
39
Barde, Etienne. "Catalyse au cobalt : applications en couplages croisés et en activation/fonctionnalisation de liaison C-H." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLET019.
Full textAbstract:
De grands progrès ont été réalisés ces cinquante dernières années en synthèse organique grâce au développement de la catalyse métallique. Parmi les différents métaux généralement utilisés, le cobalt se distingue car il est abondant, peu coûteux, peu toxique et car il offre une réactivité unique.Dans ce contexte, deux types de réaction faisant appel à une catalyse au cobalt ont été plus particulièrement étudiés durant cette thèse, les couplages croisés et l’activation de liaison C—H.Grâce à un sel de cobalt commercialement disponible et un ligand diphosphine, la fonctionnalisation d’amides α-halogénés par des réactifs de Grignard a été réalisée. Cette méthode, facile à mettre en place, s’est montrée générale car elle a permis de synthétiser une grande diversité d’amides α-fonctionnalisés par l’ajout de réactifs de Grignard de différentes natures (aromatiques, vinyliques et acétyléniques) en utilisant le même système catalytique.Ensuite, un autre sel de cobalt a été impliqué dans l’activation de liaison C—H de benzamides pour réaliser l’aminoarylation d’alkylidènes cyclopropanes. Cette méthode, qui utilise des conditions douces, a permis d’accéder à des molécules polycycliques de structure originale.Ces résultats obtenus dans deux domaines distincts de la catalyse ont pu montrer le potentiel de réactivité des sels de cobaltOrganic synthesis has been making outstanding recent progress because of the use of transition-metal catalysis into laboratory routine. Among different metals involved in catalysis, cobalt is interesting because of its low cost and toxicity but also because of its unique reactivity.During this thesis, cross-coupling and C—H bond activation reactions using cobalt complexes as catalysts were investigated.A simple catalytic system composed of diphosphine ligand and a cost-effective cobalt salt allowed us to functionnalize α-haloamides using Grignard reagents. A large variety of amides and Grignard reagents (aryl-, vinyl-, alkynyl-) were successfully tested, generating an interesting library of α-functionnalized amides.Moreover, simple cobalt salts were engaged in the activation of the C—H bond of benzamides for the aminoarylation of alkylidene cyclopropanes. Under mild conditions, original and polycyclic molecules were obtained in a single step.These results obtained in two different domains treated in this thesis demonstrate the high potential of simple cobalt salt in catalysis
40
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/.
Full textAbstract:
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.
41
Kopp, Daniel Arthur. "Mechanistic studies of electron transfer, complex formation, C-H bond activation, and product binding in soluble methane monooxygenase." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/16915.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2003.Vita.
Includes bibliographical references.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Chapter 1. Soluble Methane Monooxygenase: Activation of Dioxygen and Methane The mechanisms by which soluble methane monooxygenase uses dioxygen to convert methane selectively to methanol have come into sharp focus. Diverse techniques have clarified subtle details about each step in the reaction, from binding and activating dioxygen, to hydroxylation of alkanes and other substrates, to the electron transfer events required to complete the catalytic cycle. Chapter 2. Electron Transfer Reactions of the Reductase Component of Soluble Methane Monooxygenase from Methylococcus capsulatus (Bath) Soluble methane monooxygenase (sMMO) catalyzes the hydroxylation of methane by dioxygen to afford methanol and water, the first step of carbon assimilation in methanotrophic bacteria. This enzyme comprises three protein components: a hydroxylase (MMOH) that contains a dinuclear non-heme iron active site, a reductase (MMOR) that facilitates electron transfer from NADH to the diiron site of MMOH, and a coupling protein (MMOB). MMOR uses a non-covalently bound FAD cofactor and a [2Fe-2S] cluster to mediate electron transfer. The gene encoding MMOR was cloned from Methylococcus capsulatus (Bath) and expressed in Escherichia coli in high yield. Purified recombinant MMOR was indistinguishable from the native protein in all aspects examined, including activity, mass, cofactor content, and EPR spectrum of the [2Fe-2S] cluster. Redox potentials for the FAD and [2Fe-2S] cofactors, determined by reductive titrations in the presence of indicator dyes ...
(cont.) The midpoint potentials of MMOR are not altered by the addition of MMOH, MMOB, or both MMOH and MMOB. The reaction of MMOR with NADH was investigated by stopped-flow UV-visible spectroscopy, and the kinetic and spectral properties of intermediates are described. The effects of pH on the redox properties of MMOR are described and exploited in pH jump kinetic studies to measure the rate constant of 130 +/- s-1 for electron transfer between the FAD and [2Fe-2S] cofactors in two-electron reduced MMOR. The thermodynamic and kinetic parameters determined significantly extend our understanding of the sMMO system. Chapter 3. Structural Features of the MMOH/MMOR Complex as Revealed by Mass Spectrometric Analysis of Covalently Cross-linked Proteins. Soluble methane monooxygenase requires complexes between its three component proteins for efficient catalytic turnover. The hydroxylase (MMOH) must bind both to the reductase (MMOR) for electron transfer and to the regulatory protein (MMOB) to allow reaction with substrates. Although structures of MMOH, MMOB, and one domain of MMOR have been determined, little is known about structures of the complexes. Proteins cross-linked by a carbodiimide reagent were analyzed by specific proteolysis and capillary HPLC-mass spectrometry. Tandem mass spectra conclusively identified two amine-to-carboxylate cross-linked sites involving the alpha subunit of MMOH and the [2Fe-2S] domain of MMOR (MMOR-Fd). The amino terminus of the MMOH alpha subunit cross-links to the side chains of MMOR-Fd residues Glu56 and Glu91. These Glu residues are close to one another on the surface of MMOR-Fd and far from the [2Fe-2S] cluster ...
by Daniel A. Kopp.
Ph.D.
42
Yang, Li. "Kinetic Studies on C‐h Bond Activation in the Reaction of Triosmium Clusters with Diphosphine and Amidine Ligands." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc699850/.
Full textAbstract:
The reaction of 1-(diphenylphosphino)-2-(diphenylphosphito)benzene (PP*) and Os3(CO)10(ACN) has been investigated. A combined experimental and computational study on the isomerization of 1,2-Os3(CO)10[μ-1,2-Ph2P(C6H4)P(OPh)2] (A) and 1,1-Os3(CO)10[μ-1,2-Ph2P(C6H4)P(OPh)2] (B) and reversible ortho-metalation exhibited by the triosmium cluster B are reported. The subsequent conversion of cluster B to the hydrido cluster HOs3(CO)9[μ-1,2-PhP(C6H4-η1)C6H4P(OPh)2] (E) and the benzyne-substituted cluster HOs3(CO)8(µ3-C6H4)[μ-1,2-PhP(C6H4)P(OPh)2] (N) has been established. All of these new clusters have been isolated and fully characterized in solution by IR and NMR spectroscopy; in addition, X-ray diffraction analyses have been performed on the clusters A, B, J, and N. The ortho-metalation reaction that gives cluster E is shown to be reversible, and the mechanism has been probed using selectively deuterated PP* isotopomers. Kinetic and thermodynamic isotope data, in conjunction with DFT calculations, are presented that support the existence of an intermediate unsaturated cluster in the ortho-metalation reaction. Due to interest in the coordination chemistry of formamidines, the non-symmetric amidine ligands PhNC(Me)NHPri, PhNC(Et)NHPri, and (2,4,6-Me3C6H2)NC(Me)NHPri, have been synthesized, and their reaction with Os3(CO)10(MeCN)2 has been investigated. Of the twelve new clusters prepared in section, seven have been structurally characterized by X-ray crystallography.
43
Shiota, Yoshihito. "Theoretical Study of C-H Bond Activation by First-Row Transition-Metal Oxide Ions in the Gas Phase." Kyoto University, 2001. http://hdl.handle.net/2433/150658.
Full text
44
Roudesly, Fares. "Fonctionnalisation C-H dirigée d'hétérocycles azotés." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS354.
Full textAbstract:
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
45
Li, Yingze. "Development of New Cobalt Pincer Complexes for Catalytic Reduction Reactions." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1554215914263187.
Full text
46
Phillips, Nicholas Andrew. "N-heterocyclic carbene stabilisation of low valent metal centres for the activation of E-H bonds." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:144af4d6-3fb2-49d8-afbd-504a5cb40857.
Full textAbstract:
This thesis examines the effects of coordinating highly sterically demanding and strongly electron donating saturated N-heterocyclic carbenes (NHCs) at late transition metal centres. Chapter III details the synthesis of a range of iridium complexes of the type (NHC)2IrHxCly [x = 1, 2; y = 0, 1], bearing the saturated NHCs 5-Mes, 6-Mes and 7-Mes. Unusually facile activation chemistry is observed in the reaction of [Ir(COE)2Cl]2 with 6-Mes and 7-Mes to form the doubly cyclometallated species (6-Mes')2IrH and (7-Mes')2IrH, which were fully characterised. The responses of these complexes to the addition of dihydrogen and HCl were studied, leading to the controlled synthesis of range of precursors to 14-electron iridium cations. In Chapter IV the formation of low valent iridium cations with weakly coordinating anions is targeted. Isolation of the cationic complexes [(NHC)(NHC')IrH][BArf4] and [(NHC)2IrH2][BArf4] (NHC = 6-Mes, 7-Mes) showcases the stabilising power offered by these expanded ring systems. This allowed the study the interaction of these low valent species with a range of amine-borane substrates which are known to be readily dehydrogenated. Thermodynamic data on the C-H bond activation processes occurring at these iridium centres were able to be obtained due to facile, reversible oxidative addition of C-H bonds across the 14-electron iridium. Chapter V focuses on the effects of increasing the steric bulk of these NHCs to limit the coordination of multiple ligands at the metal centre. Use of 2,6-diisopropyl-phenyl (Dipp) groups on the expanded ring NHCs, instead of mesityl groups, leads to an unprecedented mode of reactivity with [Ir(COE)2Cl]2. Activation and cleavage of C-N bonds in the carbene ring is observed, resulting in an open chain ligand chelating to the metal centre. Activation of the backbone in this manner has allowed the synthesis of saturated NHCs bearing a weakly coordinating anion on the ring. Here the first example of an anionic, saturated NHC is reported. In Chapter VI these highly sterically demanding NHCs are exploited to stabilise active species in low valent gold chemistry. The extreme steric bulk of the 6-Dipp ligand disfavours reduction of Au(I) to Au(0), however the resulting cation is observed to interact strongly with the weakly coordinating anion, [BArf4]-. Thus, attempts were made to optimise the anion and conditions to isolate a catalytically relevant intermediate. The strong donating power of these expanded ring NHCs is also exploited to activate gold hydride complexes of the type (NHC)AuH (NHC = 6-Dipp, 7-Dipp). Analogues of [H3]+ containing gold atoms ([{LAu}2H]+ and [LAuH2]+) supported by expanded ring NHCs were also targeted.
47
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.
Full text
48
Lin, Bo-Lin Grubbs Robert H. Bercaw John E. Labinger Jay A. "A combined experimental and computational study of ligand effects on C-H bond activation by palladium and platinum complexes /." Diss., Pasadena, Calif. : California Institute of Technology, 2009. http://resolver.caltech.edu/CaltechETD:etd-04022009-144521.
Full text
49
Beydoun, Kassem. "Palladium catalyzed direct arylation of heteroaromatics via C-H bond activation : a green access to fine chemicals and materials." Rennes 1, 2012. http://www.theses.fr/2012REN1S174.
Full textAbstract:
During this thesis, we were interested in the C-H bonds activation catalyzed by palladium catalysts such PdCl(C₃H₅)(dppb) and ligand-free or ligand associated Pd(OAc)₂ for the préparation of biaryls. 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 formyl or acetyl halothiophene derivatives. The corresponding products could be further functionalized due to the presence of the halo and carbonyl groups. We have also demonstrated that the use of cyclopentyl methyl ether (CPME) as solvent, which is considered as a greener solvent compared to more toxic traditional solvents generally employed for the coupling reactions, lead to a variety of arylated heteroaromatic derivatives. We then established palladium-catalyzed systems for the selective O- or C2- arylation of non-protected phenol derivatives. We found that a simple change of the nature of the base used in this reaction would lead to different selectivities. We also studied the direct arylation of dithienylperfluorocyclopentene derivatives via palladium-catalyzed C-H activation. This method provides a simpler access for substituted photochromic molecules. In addition we showed that it is possible, using sequential addition of reagents, to prepare thieno- or furo-quinoline derivatives starting from thieno- or furo-carboxaldehyde and 2-haloaniline derivatives in a one pot reaction. We also demonstrated that palladium catalyzed direct arylation method could be applied for the arylation of ligands already coordinated to iridium complexes. With this method, a variety of complexes with different physical properties were obtainedAu cours de cette thèse, nous nous sommes intéressés à l'activation de liaisons CH catalysées par des complexes de palladium tels PdCl(C₃H₅)(dppb) et Pd(OAc)₂ pour la préparation de biaryles. Cette méthode est considérée comme un moyen de synthèse économique et respectueux de l'environnement comparé à d'autres types de couplages tels que les réactions de Suzuki, Stille ou Negishi. D'abord, nous avons démontré qu'il est possible d'appliquer la méthode d'activation de la liaison C-H pour l'arylation directe de formyle ou d'acétyle halothiophenes. Les produits correspondants pourraient être ensuite fonctionnalisés en raison de la présence des groupements halogène et carbonyle sur les produits obtenus. Nous avons également démontré que l'utilisation d'un solvant tel que le cyclopentyl méthyl éther (CPME), qui est considéré comme un solvant écologique par rapport aux solvants toxiques traditionnellement utilisés pour ces réactions de couplage, conduit à une variété de dérivés hétéroaromatiques arylés. Nous avons ensuite établi les conditions pour le couplage sélectif de phénols non-protégées par des bromures d'aryle en O ou en C2 du phenol. Nous avons constaté qu'un simple changement de la nature de la base utilisée dans cette réaction conduit à une sélectivité différente. Nous avons également réalisé l'arylation directe de dérivés dithienylperfluorocyclopentene via activation de liaisons C-H catalyse au palladium. Cette méthode a permis un accès plus simple à des molécules photochromiques. En outre, nous avons démontré qu'il est possible, via l'addition séquentielle des réactifs, de préparer des thiéno-ou furo-quinolines à partir de thiéno- ou furo-carboxaldéhydes et de 2-halogénoanilines. Nous avons aussi mis au point une méthode d'arylation directe catalysée par le palladium pour l'arylation d'un ligand déjà coordonné à des complexes d'iridium. Avec cette méthode, une variété de complexes possédant des propriétés physiques différentes a été obtenue
50
Sahnoun, Sophian. "C-H fonctionnalisation de purines : synthèse d’inhibiteurs potentiels de la HSP90." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA114803/document.
Full textAbstract:
Les résistances aux traitements actuels contre le cancer incitent à trouver de nouvelles cibles thérapeutiques. Une de ces cibles, la hsp90 (heat shock protein 90), impliquée dans la maturation de protéines clientes oncogènes, se révèle très prometteuse car son inhibition induit la dégradation de ces protéines par la voie du protéasome.PU3 et PU24S sont des inhibiteurs de la hsp90 de type purine fonctionnalisés en position 8. Dans le but d’identifier des composés encore plus actifs et/ou de nouvelles familles d’inhibiteurs, nous avons développé de nouveaux procédés sélectifs métallo-catalysés permettant l’activation de liaisons C-H de divers hétérocycles, et en particulier des purines (adénines, xanthines). Ces nouvelles approches ont permis un accès direct et simple à de nombreuses purines fonctionnalisées en C-8 par des groupements aromatiques, hetéroaromatiques, éthyléniques et benzyliquesResistance to current treatments of cancer encourages finding new therapeutical targets. The heat shock protein 90 (hsp90) is a molecular chaperon which regulates the folding of many client proteins associated with all of the six hallmarks of cancer, and helps maintaining their proper conformation. Consequently, the hsp90 has become an exciting new target in cancer drug discovery since the inhibition of its ATPase activity leads to depletion of these client proteins via the proteasomal pathway. PU3 and PU24S are purine-based hsp90 inhibitors functionalized on C-8 position. In the aim to identify more active compounds and/or new subfamilies of inhibitors, we have developed new metal-catalyzed C-H activation processes of various heterocycles including purines and other azoles. These new and simple approaches have allowed the access to numerous C-8 functionalized purines bearing (het)aryl, alkenyl and benzyl moieties