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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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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.
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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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Laren, Martijn Wouter van. "Palladium-catalyzed C-H and C-N bond formation." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2004. http://dare.uva.nl/document/75422.
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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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Truscott, Fiona Rosemary. "Transition metal catalysed C-C bond formation via C-H functionalisation." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:6a1ef296-8d63-470d-96bd-3e01a887c81f.
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The functionalisation of C-H bonds has been widely studied in organic synthesis. This work presents the results of investigation into two areas of current research, copper-catalysed aromatic C-H functionalisation and rhodium-catalysed hydroacylation. Chapter 1 presents the development of palladium- and copper-catalysed aromatic C-H functionalisation with particular attention paid to regiocontrol. Chapter 2 describes the development of copper-catalysed cross-coupling of perfluorinated arenes and alkenyl halides along with efforts to expand this methodology to a more general reaction. In Chapter 3 the development of chelation-controlled rhodium-catalysed hydroacylation is discussed. Chapter 4 outlines the utilisation of amino acid derived N-methylthiomethyl aldehydes in rhodium-catalysed hydroacylation methodology.
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Catino, Arthur John. "Oxidative C-H and C-C bond functionalization catalyzed by dirhodium caprolactamate." College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/4188.
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Thesis (Ph. D.)--University of Maryland, College Park, 2006.Thesis research directed by: Chemistry. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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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.
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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
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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.
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Locati, Abel Jean Serge. "Computational study of c-h bond cleavage and c-c bond formation processes catalyzed by transition metal complexes." Doctoral thesis, Universitat Rovira i Virgili, 2012. http://hdl.handle.net/10803/79120.
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La primera parte de la tesis se dedica al estudio del mecanismo de una reacción de activación C-H por un complejo de niobio. Se racionalizó el mecanismo de activación de enlaces C-H del benceno por el complejo TpMe2NbCH3(c-C3H5)(MeCCMe). El intermedio clave es un complejo inusual de 2-ciclopropeno. Conseguimos también racionalizar las selectividades obtenidas para la activación de varios alquilaromáticos por el complejo de niobio 2-ciclopropeno. También se investigó el papel del ligando alquino en estos complejos y su posible papel en procesos de migración de ligandos.
En la segunda parte de la tesis, se investigaron las reacciones de acoplamiento cruzado con reactivos basados en silicio. Los resultados sugieren que la transmetalación es más fácil después de la disociación de la fosfina, o cuando un ligando bromuro está coordinado al paladio. El efecto beneficioso de la dibencilidenoacetona en el acoplamiento también fue aclarado.The first part of the thesis is mainly devoted to the mechanism of a C-H activation reaction by a niobium complex. The mechanism of C-H bond activation of benzene by the TpMe2NbCH3-(c-C3H5)-(MeCCMe) complex was rationalized. The key intermediate is an unusual 2-cyclopropene complex. We rationalized the selectivities obtained for the activation of several alkylaromatics by the 2-cyclopropene niobium complex. The intriguing role of the alkyne ligand of the same complex, and its possible role in the migration processes, was investigated. In the second part of the thesis, we focused on the silicon based cross-coupling. The results suggest than the transmetalation is easier after phosphine dissociation, and in presence of the bromide ligand on the palladium. The beneficial effect of dibenzylideneacetone on the coupling was clarified.
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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/.
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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.
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Rousseaux, Sophie. "Palladium-Catalyzed C(sp2)-C(sp3) Bond Formation." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23058.
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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.
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Bahgat, Sofi-Rosamelia. "Beta-diketiminato copper complexes in C-H bond amination." Connect to Electronic Thesis (CONTENTdm), 2010. http://worldcat.org/oclc/646165084/viewonline.
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Wang, Lianhui. "Carboxylate-Assisted Ruthenium-Catalyzed Direct C-H Bond Functionalizations." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2014. http://hdl.handle.net/11858/00-1735-0000-0022-5E47-2.
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Correia, Camille. "Oxidative C-C bond formation via metal-catalyzed coupling of two C-H bonds." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114441.
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This thesis describes the formation of new C-C bonds from the direct oxidative coupling of two C-H bonds, through the use of metal catalysts for activation. First, three different oxidative Cross-Dehydrogenative-Coupling (CDC) reactions will be presented. Initially, through the use of an organic co-catalyst, N-hydroxyphthalimide (NHPI), oxygen could be utilized as the terminal oxidant for the metal catalyzed alkylation of benzylic C-H bonds with 1,3-dicarbonyls and ketones in Chapter 2. The reaction was found to be feasible for a variety of substrates with readily enolizable C-H bonds. Next, the 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) mediated alkynylation of sp3 C-H bonds was studied. A novel copper (I) triflate catalyzed CDC reaction of unactivated benzylic C-H bonds and terminal aromatic alkynes is presented in Chapter 3. After further studies, the alkynylation of benzylic ethers could also be realized in the presence of a catalytic amount of silver (I) triflate, as described in Chapter 4. Both procedures were found to be amendable for aromatic terminal alkynes, however could not be extended to aliphatic alkynes. Finally, a palladium catalyzed Minisci-type reaction will be described in Chapter 6. Peroxide generated α-hydroxyalkyl radicals could be reacted with azines in moderate to good yields. A stoichiometric amount of acid, used in the traditional Minisci reaction, was replaced by a catalytic amount of palladium dichloride.Cette thèse décrit la formation de nouvelles liaisons C-C par activation oxydative directe de deux liaisons C-H grâce à l'utilisation de métaux de transition comme catalyseurs. La première partie présentera trois différentes réactions de Cross-Dehydrogenative-Coupling (CDC) oxydantes. Dans un premier temps, sera présentée dans le chapitre 2, la réaction d'alkylation de liens C-H benzylique par 1,3-dicarbonyles et cétones. Ce system a démontré son efficacité sur une large variété de substrats contenant des liaisons C-H enolysable. De plus il a été rendu possible, grâce à l'utilisation d'un co-catalyseur organique, le N-Hydroxyphthalimide (NHPI), d'utiliser l'oxygène moléculaire comme oxydant terminal. Dans un second temps, nous étudierons l'utilisation du 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) comme médiateur pour l'alkynylation de liaisons sp3 C-H. Une nouvelle CDC réaction catalysée par le triflate de cuivre (I) sera présentée dans le chapitre 3, entre un alcyne et une liaison C-H benzylique. Le chapitre 4 présentera le développement de cette réaction à l'alcynation d'éthers benzyliques en présence d'une quantité catalytique de triflate d'argent (I). Ces deux procédures sont seulement applicables pour les alcynes vrais aromatiques. Finalement, le chapitre 6 portera sur la réaction de Minisci catalysée par le palladium. Le peroxyde radical α-hydroxyalkyl généré lors de la réaction est capable de réagir avec les azines. La quantité stœchiométrique d'acide nécessaire lors de la traditionnelle réaction de Minisci, a été remplacée par une quantité catalytique de dichloro palladium.
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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.
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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.
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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.
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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.
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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.
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Diers, Emelyne. "Ruthenium-Catalyzed Synthesis of Biaryls through C–H Bond Functionalizations." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://hdl.handle.net/11858/00-1735-0000-0001-BC4E-F.
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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.
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Li, Bin. "Ruthenium(II) catalyzed C-H bond functionalization and hydrosilylation reactions." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S114.
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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
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Grupe, Sabine [Verfasser]. "The Iron App: Reductive Iron-Catalyzed C-H and C-C Bond Formations / Sabine Grupe." München : Verlag Dr. Hut, 2013. http://d-nb.info/1047035731/34.
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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/.
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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.
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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.
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Gallardo, Donaire Juan. "Synthesis of phthalides and benzolactones via catalytic C-H functionalization/C-O bond-forming." Doctoral thesis, Universitat Rovira i Virgili, 2014. http://hdl.handle.net/10803/276960.
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El objetivo principal de esta tesis doctoral ha sido la activación de enlaces inertes C-H de
forma catalítica para la construcción de enlaces C-O. El primer proyecto desarrollado ha
consistido en la funcionalización de enlaces C(sp3)-H para la síntesis directa de phthalides
catalizado por Pd, utilizando simples ácidos benzoicos como materiales de partida.
Continuando con la misma línea de investigación, el segundo proyecto realizado se ha
basado en la utilización de catalizadores simples y de bajo coste de Cu para la
funcionalización de enlaces C(sp2)-H/formación de enlaces C-O para la síntesis de
benzolactonas. Finalmente, se ha desarrollado una metodología libre de metales para la
síntesis de benzolactonas generando reactivos hipervalentes de I(III) de forma catalítica.The main objective of this Thesis has been the activation of inert C-H bonds catalytically for the construction of C-O bonds. The fist project developed consisted on the activation of C(sp3)-H bonds for the direct synthesis of phthalides catalyzed by Pd, employing simple benzoic acids as starting materials. Continuing in the same research line, the second project described deals with the utilization of cheaper and easy to handle Cu salts as catalyst for the functionalization of C(sp2)-H bonds towards the formation of C-O bonds for the synthesis of benzolactones. Finally, the last project discovered handles a metal-free C-H functionalization approach for the synthesis of benzolactones by using simple iodoarenes as catalyst, thus
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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.
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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.
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Fallon, Brendan. "Cobalt-catalyzed bond activation : C-H functionalization, hydrosilylation and coupling reactions." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066411/document.
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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
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Pearson, Stephen. "High oxidation state carbene complexes for C-H bond activation catalysis." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/7570.
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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.
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Kossen, Hanno. "Exploration of Brønsted base catalysis for formal C–H bond activations." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/23598.
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This PhD project investigates the use of (Lewis or Brønsted) bases in catalysis. While the first chapter explores the use of main group metal amides in C–H bond activation reactions, the second chapter focusses on metal-free organocatalysis using so-called carbones. In the first chapter, formal allylic C(sp3)–H bond activations of unfuctionalised alkenes for C–C bond formations with imines were investigated. Alkali metal amides were used as catalysts for these transformations, giving homoallylic amine products. The investigations showed the unique reactivity of the Na-amide catalyst compared to other metal base complexes. The reaction scope and robustness was explored and initial insights into the reaction mechanism were obtained. A related K-amide catalyst was then developed for the isomerisation of allyl benzenes, as well as functionalised olefins such as allylic silanes, boronic esters, phosphines, amines, ethers, and thioethers. This part explored the use of ligands to increase the catalyst’s selectivity. Finally, the metal- or functional group-substituted classes of reagents were used in the functionalised allylation of imines, giving highly complex molecules with a diverse range of applications. Here, unprecedented reactivities were observed for the use of allyl–M reagents, as the allylation involved the activation of C–H bonds rather than C–X bonds. Furthermore, new catalytic formations of heteroatom-substituted homoallylic amines were described. The following chapter focussed on the use of carbodiphosphoranes (CDPs) in catalysis. These C(0) bases, or carbones, represent a class of heteroallene compounds that exhibit a high electron density on a P(V)-flanked carbon centre. Their potential as either a Lewis or Brønsted base was examined. Different CDPs were synthesised and reacted stoichiometrically with CO2, boron Lewis acids and metal salts. The generated intermediates were then studied in their reaction behaviour, taking advantage of a potentially available second pair of electrons. The results of these reactions were compared to other carbon bases, such as carbenes or other carbones. Finally, the Brønsted basicity of the CDP was examined in reactions with acidic pro-nucleophiles. The conjugate addition of alkylnitriles to α,β- unsaturated amides was developed using a catalytic amount of CDP. To the best of our knowledge, the first catalytic use of a CDP, as well as the first C–H bond activation of acetonitrile in Michael additions was reported.
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Teskey, Christopher. "Strategic use of transition metals for selective C-H bond functionalisation." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/strategic-use-of-transition-metals-for-selective-ch-bond-functionalisation(496828e4-75db-428e-afb5-0138d55c3258).html.
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The ability to selectively react C-H bonds in organic molecules is a field within synthetic chemistry that has grown substantively in the last few decades. The interest in this area emanates from the desire to maximise atom economy: this approach obviates the need for pre-functionalised starting materials and stoichiometric organometallic reagents. However, organic molecules typically contain many different C-H bonds with little difference in bond energy which can make selective functionalisation difficult to achieve. Herein is described how ruthenium catalysis was shown to effect meta-bromination on substituted 2-phenylpyridines. This novel procedure shows a marked contrast to other transition metal catalysed bromination procedures which are selective for the ortho-position of the phenyl ring. It was shown that this methodology was compatible with more traditional palladium catalysed chemistries (Suzuki-Miyaura and Heck reactions) in the same pot which enabled the development of procedures for one-pot meta-arylation and meta-alkenylation. Mechanistic postulation on the meta-bromination procedure led to the discovery of several interesting new meta-selective C-H functionalisation reactions with ruthenium catalysis. The early investigations, together with the challenges faced, are described. Subsequent investigations into other halogenating agents with ruthenium catalysis showed that iodine monochloride gave interesting results, with switchable chemoselectivity through variance of catalyst giving ortho-chlorinated or ortho-iodinated products. Also presented is a copper mediated coupling of electron rich arenes and toluene-like molecules to give (halo)diarylmethanes. This formal cross dehydrogenative coupling strategy tolerates a wide range of coupling partners for both the electron rich arene and the tolyl-component. Mechanistic studies suggest that the reaction proceeds via a copper mediated coupling of an in situ generated aryl bromide with a benzylic radical species.
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Toh, Qiao Yan. "Organocatalysis in total synthesis and C-H bond arylation of aldehydes." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648134.
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Gu, Yiting. "C-H & C-O Functionalization by Silicon-Heteroatom Interelement Linkage." Doctoral thesis, Universitat Rovira i Virgili, 2019. http://hdl.handle.net/10803/668961.
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La química sintètica és gairebé inimaginable sense tres elements principals del grup, a saber, boro, silici i estany. Quan s'uneixen a un àtom de carboni de qualsevol hibridació, aquests grups funcionals serveixen de linchpins excepcionalment versàtils en síntesi, transformant-se selectivament en una enorme amplitud d'enllaços C-C i C-X, per tant, descobrir nous mètodes per forjar el valor afegit C-Si, Els enllaços C-B i C-Sn sempre tenen una gran demanda.
D'acord amb l'interès de la investigació en el grup de Martín per activar enllaços o molècules inerts, aquesta tesi doctoral se centra en el desenvolupament de noves tècniques per fer ús de l'enllaç d'interrelació de silici-heteroatoma per funcionalitzar l'enllaç C-O i C-H inerts mitjançant una catàlisi de níquel o sistema lliure de transició de metalls.
Hem desenvolupat tres nous mètodes per a la funcionalització d’enllaços C-O i C-H inerts mitjançant l’ús d’enllaços d’interrelació basats en silici. Totes les transformacions anteriors presenten un excel·lent perfil de quimioselectivitat en condicions suaus. Es duen a terme estudis i debats sobre mecanismes previs per entendre com i per què van continuar aquestes reaccions. Les transformacions realitzades contribueixen a la comprensió de l’ús més prolífic d’enllaços químics inerts en els compostos de valor afegit de síntesi. Creiem que aquests protocols contribuirienLa química sintética es casi inimaginable sin tres elementos principales del grupo, a saber, boro, silicio y estaño. Cuando se unen a un átomo de carbono de cualquier hibridación, estos grupos funcionales sirven como linchpins excepcionalmente versátiles en síntesis, transformándose selectivamente en una enorme variedad de enlaces C-C y C-X, por lo tanto, descubren nuevos métodos para forjar el valor agregado C-Si, Los bonos C-B y C-Sn siempre tienen una gran demanda. En línea con el interés de la investigación en el grupo de Martín de la activación de enlaces o moléculas inertes, esta tesis doctoral se centra en el desarrollo de nuevas técnicas para hacer uso del enlace de interelemento de silicio-heteroátomo para funcionalizar el enlace inerte C-O & C-H a través de catálisis de níquel o sistema sin transición de metal. Hemos desarrollado tres nuevos métodos para la funcionalización de enlaces inertes C-O y C-H mediante el uso de enlaces de interelemento basados en silicio. Todas las transformaciones anteriores muestran un excelente perfil de quimioselectividad en condiciones suaves. Se realizan estudios y debates mecanicistas preliminares para comprender cómo y por qué se produjeron estas reacciones. Las transformaciones realizadas contribuyen a la comprensión del uso más prolífico de enlaces químicos inertes a los compuestos de valor agregado de síntesis.
Synthetic chemistry is almost unimaginable without three main group elements, namely, boron, silicon, and tin. When attached to a carbon atom of any hybridization, these functional groups serve as exceptionally versatile linchpins in synthesis, selectively transforming into an enormous breadth of C-C and C-X bonds, thus, discover new methods to forge value added C-Si, C-B and C-Sn bonds are always in highly demand. In line with the research interest in Martín’s group of activating inert bonds or molecules, this doctoral thesis focuses on the development of novel techniques to make use of silicon-heteroatom interelement linkage to functionalize inert C-O & C-H bond via either nickel catalysis or transition metal free system. We have developed three new methods towards the functionalization of inert C-O & C-H bonds by using silicon-based interelement linkages. All the above transformations display excellent chemoselectivity profile under mild conditions. Preliminary mechanistic studies and discusses are carried out to understand how and why these reactions proceeded. The transformations realized contribute to the understanding of more prolific use of inert chemical bonds to the synthesis value added compounds. We believe these protocols would definitely contribute to a systematic utilization of silicon-heteroatom reagent in the arena of inert chemical bond functionalization.
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Wang, Chang-Sheng. "Selective catalytic C(sp²)–H and C(sp³)–H bond functionalizations for the synthesis of phosphorus and nitrogen containing molecules." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S106/document.
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Dans la thèse de doctorat, nous avons développé une approche efficace pour la modification rapide d'oxydes d'arylphosphines via la fonctionnalisation de liaisons C-H en position ortho du groupement P=O catalysée par le ruthénium (II) en présence des alcènes. Intéressement, l'ajustement du pH du milieu réactionnel permet de contrôler la sélectivité de la réaction à savoir alkylation or oléfination. La réduction des oxydes de phosphines fonctionnalisées permet la formation d'arylphosphines portant un carboxylate flexible. Dans le second objectif, un couplage C(sp3)–H /N-H oxydatif catalysé par le cuivre a permis l'alkylation d'hétérocycles à partir de (cyclo alcanes abordables. Ce protocole implique la formation de liaisons C (sp3)–N via une voie radicalaire générée par un clivage homolytique du peroxyde de di-tert-butyle et le piégeage du ou des radicaux par des catalyseurs au cuivre. Dans une troisième partie, nous avons utilisé ces processus radicalaires pour la fonctionnalisation le liassions C(sp3)–H benzylique d'oxyde de 2-alkylpyridines. Ces transformations impliquent un processus en cascade : estérification oxydative catalysée par le cuivre suivie d'un transfert d'atome d'oxygène. Enfin, des dérivés tosylés de pyridin-2-ylméthyl ont été obtenus avec des rendements élevés à partir des oxide de 2-alkylpyridines grâce à un réarrangement sigmatropic [3,3] du produit d'addition entre les oxides de 2-alkylpridine avec des chlorures de chlorure de benzènesulfonyles. De plus, les alkylnitrones subissent également ce réarrangement sigmatropique [3,3] pour donner des cétones α-tosylées après hydrolyseIn the first chapter, we have developed an efficient approach for the fast modification of arylphosphine oxides using ruthenium(II)-catalyzed C–H bond functionalization with alkenes. Interestingly, we have found that the selectivity of the reaction, namely alkylation versus alkenylation, is depending on the reaction pH. The reduction of the phosphine oxide allows the formation of aryl phosphines bearing a flexible pendent carboxylate. In the second objective, a copper-catalyzed oxidative C(sp3)–H/N–H coupling of NH-heterocycles with affordable (cyclo)alkanes was developed. This protocol involved C(sp3)–N bond formation via a radical pathway generated by a homolytic cleavage of di-tert-butyl peroxide and trapping of the radical(s) by copper catalyst.In a third part, benzylic C(sp3)–H acyloxylation of 2-alkylpyridine, 2-alkylpyrazine and 2-alkylthiazole compounds was achieved using simple aldehydes via a copper-catalyzed tandem reaction, involving oxidative esterification followed by O-atom transfer. Finally, pyridin-2-ylmethyl tosylate derivatives are obtained in high yields from 2-alkylpyridine N-oxides via a [3,3]-sigmatropic rearrangement of the adduct between 2-alkylpridine N-oxides with benzenesolfonyl chlorides. Moreover, alkylnitrones also underwant [3,3]-sigmatropic rearrangement to give α-tosylated ketones after hydrolysis
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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.
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Hofmann, Nora. "Carboxylate-Assisted Ruthenium-Catalyzed C-H Bond meta-Alkylations and Oxidative Annulations." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://hdl.handle.net/11858/00-1735-0000-0014-D4A4-1.
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Zhao, Liang. "Functionalization of the C-H bond adjacent to a secondary nitrogen atom." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=86795.
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This thesis is about the development of new methods to introduce functionalities directly to compounds with a secondary nitrogen atom via C-H bond oxidation.A copper-mediated oxidative coupling between glycine derivatives (including short peptides) and nucleophiles (including malonates, aryl alkynes, arylboronic acids and indoles) were developed. Later, a chiral chlorosilane induced asymmetric indolation of imino amides was also studied. In addition, a study on the α-arylation of tetrahydroisoquinoline with iodobenzene was presented. The reaction was proposed to undergo via palladium catalyzed β-hydride elimination, imine insertion pathway.
This thesis also described a three-component coupling reaction of aldehyde, alkyne and alkyl hydroxylamine catalyzed by CuCl/bipy complex to synthesize β-lactam was presented.
In the end of the thesis, a collaboration work with the Department of Biochemistry on the study of thioxothiazolidinone derivatives as the cellular inhibitor of protein tyrosine phosphatase 1B was presented. The thioxothiazolidinone derivatives were synthesized and the bioactivities were studied.
Cette thèse a pour sujet le développement de nouvelles méthodes pour la fonctionnalisation directe de composés possédant des amines secondaires via l'oxydation de liaisons C-H.
Dans la première partie de cette thèse, un couplage oxydant au cuivre entre des dérivés de la glycine (incluant des peptides de petite taille) et des nucléophiles est présenté. L'indolisation asymétrique d'amides aminés induit par une silicone chlorée est également étudiée. Cette partie se termine par une étude de l'arylation-alpha de la tetrahydroisoquinoline avec de l'iodobenzène. Une voie mécanistique catalysée par le palladium, faisant intervenir une β-H élimination suivie d'une insertion d'imine est proposée. fr
Dans la deuxième partie de cette thèse, est présenté une réaction de couplage à trois composés entre aldéhydes, alcynes et hydroxylamines alkyles, catalysée par un complexe CuCl/bipy, pour la synthèse de β-lactames. fr
Dans la dernière partie de cette thèse, est présenté un travail en collaboration avec le département de biochimie sur l'étude de dérivés de thioxothiazolidinone comme inhibiteurs cellulaires de la protéine tyrosine phosphatase 1B. Ces dérivés de thioxothiazolidinone furent synthétisés et leurs activités biologiques furent étudiées. fr
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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.
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Song, Weifeng. "Cobalt- and Nickel-Catalyzed Functionalization of Unactivated C–Hal, C–O and C–H Bonds." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://hdl.handle.net/11858/00-1735-0000-0001-BC70-0.
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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.
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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
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To, Wai-pong, and 杜偉邦. "Transition metal catalysed photo-induced oxidative C-H bond functionalization and water oxidation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hdl.handle.net/10722/193012.
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A series of cyclometalated gold(III) complexes with N-heterocyclic carbine (NHC) or alkynyl as auxiliary ligand were synthesized and characterized. Complexes [AuIII(R1
–C^N^C)(NHC)](OTf) and [AuIII(C^N^C)(C≡CR2)] (HC^N^CH = 2,6-di(naphthalene-2-yl)pyridine; R1 = H or 4-methoxyphenyl; R2 =aryl) are emissive in solution at room temperature with quantum yields in the range of 0.65–11.4% and lifetimes ranging from 98 to 506 s. [AuIII(4-(4-OMePh)–C^N^C)(NHC)](OTf) showed prominent photochemical properties. This complex effectively catalyses photo-induced oxidation of secondary amines (to the corresponding imines) and -functionalization of tertiary amines in good to excellent yields; it also acts as a photosensitizer for hydrogen generation in a water/acetonitrile mixture, producing more than 350 turnovers of hydrogen after 4 hours of irradiation.
Palladium(II) meso-tetrakis(pentafluorophenyl)porphyrin was found to be an efficient and robust catalyst for the photo-induced oxidative C–H bond functionalization reactions. Several kinds of -functionalized tertiary amines were obtained in good to excellent yields by irradiating a mixture of palladium(II) catalyst, corresponding tertiary amine and nucleophile under aerobic conditions. The nucleophiles for these reactions include cyanide, nitromethane, dimethyl malonate, diethyl phosphite and acetone. Two examples of novel intramolecularly cyclized amines were also described. Comparison of the UV-vis absorption spectra before and after reaction indicated that the palladium catalyst was highly robust. The practical potential of this catalyst was shown by the success in reactions at a low catalyst loading and on a large scale. The palladium(II) catalyst could also sensitize photo-induced oxidation of sulfide to sulfoxide and photo-induced hydrogen production in a water/acetonitrile mixture with up to 240 turnovers.
[FeIII(L-N4Me2)Cl2][FeCl4] (L-N4Me2 = N,N’-dimethyl-2,11-diaza[3,3] (2,6)pyridinophane) was demonstrated to be an active catalyst for water oxidation. When cerium ammonium nitrate (CAN) was used as the oxidant, the iron(III) catalyst oxidized water to oxygen with up to 93 turnovers after 30 minutes in 0.1 M nitric acid, whereas changing the oxidant to sodium periodate (NaIO4) resulted in only 44 turnovers of oxygen after 30 minutes. The mechanism of the reaction was explored by high resolution electrospray ionization mass spectrometry (ESI-MS), 18O labeling, UV-vis absorption spectroscopy, kinetic plots and DFT calculations. In the case of using CAN, an FeIV-oxo species was detected by ESI-MS and UV-vis absorption spectroscopy. The rate of oxygen evolution was found to be linearly dependent on both concentrations of catalyst and oxidant. 18O labeling studies confirmed that the origin of oxo ligands was from water and was irrespective of the choice of oxidant. This reaction was proposed to involve a coupling between an FeIV-oxo species and a hydroxocerium(IV) radical. In the case of using NaIO4, an FeV-dioxo species was detected by ESI-MS as a major species, and a small amount of FeIV-oxo species was detected by UV-vis absorption spectroscopy. As the rate of oxygen evolution was found to be linearly dependent on the concentration of catalyst only, the reaction was proposed to involve a cis-FeV-dioxo species. DFT calculations showed that the cis-FeV-dioxo species was capable of oxidizing water to oxygen through the formation of an [FeIII(L-N4Me2)(OO?)(OH)]+ intermediate.published_or_final_version
Chemistry
Doctoral
Doctor of Philosophy
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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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Bheeter, Charles Beromeo. "Palladium-catalysed C-H bond activation for simpler access to ArSO₂R derivatives." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S171.
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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
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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.
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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
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Fenner, Sabine [Verfasser], Lutz [Akademischer Betreuer] Ackermann, and Ulf [Akademischer Betreuer] Diederichsen. "Sustainable Strategies for Site-Selective C−VC Bond Formations through Direct C−H Bond Functionalizations / Sabine Fenner. Gutachter: Lutz Ackermann ; Ulf Diederichsen. Betreuer: Lutz Ackermann." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2012. http://d-nb.info/1043767320/34.
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Zhao, Qun. "Palladium-catalyzed directed introduction of α-CF3-vinyl and SCF3 groups by C-H bond functionalization." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMIR15.
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Ces dernières années ont été témoin de l'énorme développement de la chimie organique du fluor. Notamment, l'introduction de groupements fluorés émergents sur des « briques » moléculaires variées a attiré l'attention de la communauté scientifique en raison de leurs propriétés particulières. De plus, la stratégie de fonctionnalisation dirigée de la liaison C-H par catalyse par les métaux de transition, a conduit à une révolution dans le développement de méthodologies synthétiques originales. Par conséquent, la conception de nouvelles approches synthétiques pour l'introduction de groupements fluorés par fonctionnalisation de la liaison C-H catalysée par les métaux de transition est particulièrement attirante. Dans cette thèse, nous nous sommes concentrés sur le développement de nouvelles méthodologies d'introduction directe des groupements fluorés sur des arènes et des oléfines par fonctionnalisation directe de liaison C(sp2)-H catalysée par les métaux de transition. En particulier, nous avons tourné notre attention sur le 2-bromo-3,3,3-trifluoropropène (BTP), un réactif fluoré bon marché et provenant de déchets de l'industrie. Ce dernier est utilisé comme agent de remplacement de halon pour la suppression des incendies et, utilisé comme « brique » moléculaire en synthèse organique (Chapitre 1). La première partie de cette thèse est dédiée au développement de nouvelles méthodologies pour l'introduction directe du groupement CF3-vinyl sur des arènes et des oléfines par fonctionnalisation de la liaison C(sp2)-H catalysée par le palladium. Ensuite, cette approche a été étendue à la fonctionnalisation d'esters α,β- insaturés, bien qu'un mécanisme différent soit probablement impliqué (Chapitre 2). Dans la seconde partie de cette thèse, nous avons développé une nouvelle méthodologie pour l'introduction directe du groupement SCF3 sur des arènes et des oléfines par fonctionnalisation de la liaison C(sp2)-H catalysée par le palladium, utilisant le réactif de Munavalli (Chapitre 3)Recent years have witnessed a great development of the organofluorine chemistry field. In particular, the introduction of emergent fluorinated moieties onto various scaffolds has attracted attention of the scientific community because of their special properties. Besides, transition metal-catalyzed directed C-H bond functionalization strategy has brought a revolution in the development of original synthetic methodologies, since it allows straightforward and more atom-economical processes. Thus, the design of new synthetic approaches for the introduction of fluorinated moieties by transition metal-catalyzed C-H bond functionalization pathway is particularly appealing. Therefore, in this Ph.D. thesis, we focused on the development of new methodologies for the direct introduction of fluorinated moieties onto arenes and olefins by transition metal catalyzed directed C(sp2)-H bond functionalization. In particular, we turned our attention to the 2-bromo-3,3,3-trifluoropropene (BTP), an inexpensive fluorinated reagent coming from industry waste, used as a potential halon replacement for fire suppression and as a fluorinated building block in organic synthesis (Chapter 1). The first part of this Ph.D. thesis was dedicated to the development of new methodologies for the direct introduction of a CF3- vinyl moiety onto arenes and olefins by a Pd-catalyzed directed C(sp2)-H bond functionalization with BTP. Then, this approach was extended to the functionalization of α,β-unsaturated esters, although a different reaction pathway is probably involved (Chapter 2). In the second part of this Ph.D. thesis, we developed a new methodology for the direct introduction of the SCF3 group onto arenes and olefins by Pd-catalyzed directed C(sp2)-H bond functionalization using the Munavalli reagent (Chapter 3)
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Borràs, Noguera Carlota. "Sustainable and cost-effective development of chiral metal-catalysts for C-H and C-X bond forming reactions." Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/664741.
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L’obtenció de compostos enantiomèricament purs ha esdevingut una necessitat que ha conduit a un important progrés en la catàlisi asimètrica, principalment usant compostos organometàl•lics quirals. Entre les diferents estratègies en l’optimització dels catal•litzadors per aconseguir elevades selectivitats i activitats, el disseny i correcta selecció de lligands quirals, modificant-ne les seves propietats és fonamental i la més utilitzada. Que un lligand sigui fàcil de sintetitzar a partir de compostos de partida accessibles i que aquests lligands siguin estables i fàcils de manipular, tenen un elevat interès en la industria.
En aquest context, el principal objectiu d’aquesta tesi és la síntesi de diferents famílies de lligands quirals, acomplint els requisits prèviament esmentats, i la seva posterior aplicació a diverses reaccions asimètriques d’elevat interès industrial: hidrogenació d’olefines funcionalitzades i no funcionalitzades catalitzada per Rh i Ir, hidrogenació de cetones catalitzada per Ir, reaccions de substitució al•lílica catalitzades per Pd i reaccions de substitució propargílica catalitzada per Cu. S’han sintetitzat diverses famílies fosfit/fosfinit-tioèter/selenoèter, carbè-tioèter, amino-fosfit/fosfinit/fosfina, i varies famílies de lligands tridentats.La obtención de compuestos enantioméricamente puros se ha convertido una necesidad que ha conducido a un importante progreso en la catálisis asimétrica, principalmente usando compuestos organometalicos quirales. Entre las diferentes estrategias en la optimización de los catalizadores para conseguir elevadas selectividades y actividades, el diseño y la correcta selección de ligandos quirales, modificando sus propiedades es fundamental y la más utilizada. Que un ligando sea fácil de sintetizar a partir de compuestos de partida accesibles y que estos ligandos sean estables y fáciles de manipular, tienen un elevado interés en la industria. En este contexto, el principal objetivo de esta tesis es la síntesis de distintas familias de ligandos quirales, cumpliendo con los requisitos previamente mencionados, y su posterior aplicación en distintas reacciones asimétricas de alto interés industrial: hidrogenación de alquenos funcionalizados y no funcionalizados catalizados por Rh y Ir, hidrogenación de cetonas catalizada por Ir, reacciones de substitución alílica catalizada por Pd y reacciones de substitución propargílica catalizada por Cu. Se han sintetizado diferentes familias de ligandos Fosfito/fosfinito-tioéter/selenoéter, carbeno-tioéter, amino-fosfito/fosfinito/fosfina, y varias familias de ligandos tridentados.
The obtaining of enantiomerically pure compounds has become a need that led to an important progress in asymmetric catalysis, mainly using organometallic chiral compounds. Among different strategies to optimize catalysts in order to obtain high selectivities and activities, the design and the correct selection of chiral ligands, modifying their properties, is fundamental and the most used strategy. Ligands easy to synthesize from readily accessible starting material and stable and easy to manipulate ligands, have a high interest in the industry. In this context, the main objective of this thesis is the synthesis of different chiral ligand families, according to the previously mentioned requirements, and their application in different asymmetric reactions with high industrial interest: Rh- and Ir-catalyzed hydrogenation of functionalized and minimally functionalized olefins; Ir-catalyzed hydrogenation of simple ketones; Pd-catalyzed asymmetric substitution of allylic acetates and Cu-catalyzed propargylic substitution. There have been synthesized different phosphite/phosphinite-thioether/selenoether, carbene-thioether, amino-phosphite/phosphinite/phosphine and various tridentated ligand families.
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Baslé, Olivier. "Oxidative generation of reactive iminium-intermediates: A powerful strategy for C-H bond functionalization." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=86908.
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This thesis is an investigation on the generation and reactivity of carbocations adjacent to a trisubstituted nitrogen atom (iminium).In the first part of this thesis, a copper-catalyzed oxidative alkylation of sp3 C-H bond adjacent to a nitrogen atom is described. This environmentally respectful process used molecular oxygen as oxidant and water as solvent.
In the second part of the thesis, an aerobic sp3 C-H bond phosphonation reaction is presented. This process catalyzed by copper(I) bromide using dialkylphosphites as nucleophiles offered direct C-P bond formation via direct oxidative coupling of C-H and P-H bonds.
In the third part of the thesis, a copper-catalyzed sp3 C-H bond arylation with boronic acids in absence of directing group is described. The oxidative arylation reaction provided easy access to biologically active tetrahydroisoquinoline derivatives and can either use peroxide or molecular oxygen as oxidant.
In the last part of the thesis, the aerobic and electrochemical Cross-Dehydrogenative-Coupling in ionic liquids is presented. Ionic liquids have demonstrated high efficiency when applied as solvent and electrolyte solvent for the oxidative nitro-Mannich carbon-carbon bond formation.
Cette thèse est une investigation sur la génération et la réactivité de carbocations adjacents à un atome d'azote trisubstitué (iminium).
Dans la première partie de cette thèse, une alkylation d'une liaison sp3 C-H adjacente à un atome d'azote catalysée au cuivre est décrite. Ce procédé respectueux de l'environnement utilisa l'oxygène comme oxydant et l'eau comme solvant.
Dans la deuxième partie de cette thèse, une réaction aérobique de phosphonation de liaison sp3 C-H est présentée. Ce procédé catalysé par un sel de bromure de cuivre(I) et utilisant des bis-alkylphosphites comme nucléophiles permit la synthèse directe de liaisons C-P via le couplage oxydant de liaisons carbone-hydrogène et phosphore-hydrogène.
Dans la troisième partie de cette thèse, une réaction d'arylation de liaison sp3 C-H, catalysée par le cuivre, avec des acides boroniques en absence de groupement directeur est décrite. Cette réaction d'arylation, utilisant soit un peroxyde soit l'oxygène comme oxydant, donna des dérivés de la tétrahydroisoquinoline biologiquement actifs.
Dans la dernière partie de cette thèse, le couplage croisé déshydrogénant aérobique et électrochimique en liquides ioniques est présenté. Les liquides ioniques ont démontré une grande efficacité pour la formation de liaisons C-C (nitro-Mannich oxydante) lors de leurs utilisations comme solvant et solvant électrolyte.
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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.
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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/.
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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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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.
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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