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Thematische Bibliographien / Catalytic C-H / Dissertationen

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Dissertationen zum Thema „Catalytic C-H“

Autor: Grafiati

Veröffentlicht am 6. September 2023

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1

Leitch, Jamie. „Site selective catalytic C-H functionalisation“. Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.767559.

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Harnessing site selectivity in C-H functionalisation remains one of the greatest challenges in modern catalysis. In order to differentiate electronically and sterically similar C-H bonds, a variety of pioneering methods have been developed in recent years. One of the key developments is the use of Lewis basic directing groups to selectively direct a metal centre. The results herein report the manipulation of directing group chemistry to allow selective ortho, meta and para C-H functionalisation of arenes. Chapter 1 reports the developments in moving beyond ortho-selectivity in transition metal catalysed C-H functionalisation chemistry. Chapter 2 reports the use of the biologically relevant oxazolidinone and hydantoin heterocycles as weakly coordinating directing groups in ruthenium catalysed ortho-C-H alkenylation methodology. Chapter 3 reports the application of ruthenium catalysed σ-activation to the remote C-H functionalisation of indoles at the C6 position and carbazoles at the C4 position. Chapter 4 reports the manipulation of site selective cyclometalation and its application in the para-C-H alkylation of aniline derivatives.

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2

Reynolds, William. „Sequential processes involving catalytic C-H functionalisation“. Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642028.

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The work described herein involves the exploration of sequential reaction processes involving catalytic C-H functionalisations and Pd-catalysed cross-couplings in both batch and continuous-flow operation, in an effort to improve overall reaction efficiencies.

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3

Paterson, Andrew. „Selective catalytic C-H functionalisation for drug discovery“. Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.720659.

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This thesis details the current methods for meta-selective C-H functionalisation and contains three chapters relating to the area of ruthenium catalysed meta selective functionalisation by σ-activation. The first of which contains a published manuscript entitled “Catalytic meta-selective C-H functionalization to construct quaternary carbon centres” and describes a meta selective tertiary alkylation procedure on 2-phenylpyridine substrates. Key findings from this work provide good evidence for a radical based mechanism and proposes a catalytic cycle involving two distinct roles for the ruthenium catalyst; both in the activation of the substrate molecule and in the formation of a tertiary radical coupling partner. The second chapter contains another published manuscript entitled “Mechanistic insight into ruthenium catalysed meta-sulfonation of 2-phenylpyridine” and provides mechanistic analysis for the meta selective sulfonation of 2-phenylpyridine. Key findings from this work show through stoichiometric experiments that sulfonation occurs at the position para to the C-Ru bond formed following cyclometalation with a radical addition being implied. The work also shows that the catalytic species involved do not require an arene ligand and deuterium labelling studies identified a likely rate limiting radical sulfonation step. The final chapter contains additional work relating to the use of α-halo carbonyl coupling reagents to enable meta selective primary, secondary and tertiary alkylations. The use of a triphenylphosphine ligand source was necessary for the coupling of primary α-halo carbonyl coupling partners at the meta position. Crucially, this transformation was not possible with simple, straight-chain alkyl halides, highlighting the privileged reactivity of α-halo carbonyl coupling reagents. This work also contains experimental and computational mechanistic analysis which reveals additional support for a dual activation pathway.

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4

Ingner, Fredric. „Preparation of carbazolyne precursors through catalytic C-H functionalization“. Thesis, Uppsala universitet, Organisk kemi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-307497.

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5

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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6

Stateman, Leah Marie. „Catalytic Strategies for Remote C-H Functionalization of Alcohols and Amines“. The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587554146078308.

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7

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 hydrolyse
In 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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8

Gerdes, Gerd. „Catalytic C-H activation of benzene by plantinum(II) : a mechanistic study /“. Zürich, 2004. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=15631.

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9

Sankey, Rosalind Fay. „Beyond C-H activation : the preparation of novel heterocycles using catalytic dearomatisation“. Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.559388.

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The continuous drive for efficient bond forming reactions has led to the emergence of C-H activation methodologies. More specifically, direct arylation reactions are commonly employed in the synthesis of a range of heteroaromatic products. The latter make up a considerable proportion of medicinally important compounds and therefore their rapid and efficient synthesis is paramount. The preparation of carbazoles has been extensively developed within the Bedford group. The expansion of this palladium-catalysed intramolecular direct arylation methodology has been explored with the aim of producing interesting heterocycles, namely acridans and acridines. Interestingly, instead of the expected C-H activation reaction, an unprecedented catalytic dearomatisation reaction took place. This was developed into a more general methodology to produce a range of novel heterocycles, including 4a-alkyl-4aH- carbazoles and dihydroindolo[2,3-b]indoles. Due to their instability these heterocycles undergo a range of interesting transformations, including dimerisation, dealkylation and hydro lysis reactions. Furthermore, it was proposed that typical direct arylation reactions could be occurring via a catalytic dearomatisation mechanism rather than one of the more generally accepted C-H activation mechanisms. A detailed kinetic study has been carried out. Although evidence to support a dearomatisation mechanism could not be obtained, the turnover-limiting step for two substrates could be proposed and a number of interesting observations made.

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10

Khan, Imtiaz. „Enolate-directed catalytic C-H functionalization of 2-aryl-1,3-dicarbonyl compounds“. Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/30261/.

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I) Synthesis of Spiroindenes by Enolate-Directed Ruthenium-Catalyzed Oxidative Annulation of Alkynes with 2-Aryl-1,3-dicarbonyl Compounds The synthesis of carbocycles by the ruthenium-catalyzed oxidative annulation of alkynes with 2-aryl cyclic 1,3-dicarbonyl substrates is described. Proceeding by the functionalization of C(sp3)–H and C(sp2)–H bonds, and the formation of all-carbon quaternary centers, the reactions provide a diverse range of spiroindenes in good yields and high levels of regioselectivity. II) Synthesis of Benzopyrans by Pd(II)- or Ru(II)-Catalyzed C–H Alkenylation of 2-Aryl-3-hydroxy-2-cyclohexenones We have explored the 2-aryl-3-hydroxy-2-cyclohexenones as competent substrates for palladium- and ruthenium-catalyzed C–H alkenylation reactions with terminal alkenes. This process affords benzopyrans, in most cases, with good functional group tolerance. III) Synthesis of Spiroindanes by Palladium-Catalyzed Oxidative Annulations of 1,3-Dienes Involving C–H Functionalization 1,3-Dienes have been an underexplored class of substrates in catalytic oxidative annulation reactions involving C‒H functionalization. The synthesis of spiroindanes by the palladium-catalyzed oxidative annulation of 1,3-dienes with 2-aryl cyclic 1,3-dicarbonyl compounds is described. Several examples of the dearomatizing oxidative annulation of 1,3-dienes with 1-aryl-2-naphthols are also presented. IV) Enantioselective Spiroindene Formation via C‒H Functionalization Using Chiral Cyclopentadienyl Rhodium Catalysts A chiral cyclopentadienyl rhodium ligand with an atropchiral biaryl backbone enables an asymmetric synthesis of spiroindenes from 2-aryl-1,3-dicarbonyl compounds and alkynes. The process affords a range of products with all-carbon quaternary center in high yields and excellent enantiselectivities. The good functional group tolerance and broad substrate generality are the advantages of this reaction.

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11

Ihara, Hideki. „Directed Catalytic C-H Functionalization of Organoboronic Acids Utilizing Removable Directing Groups on the Boron Atom“. 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188545.

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12

Garcia, Bosch Isaac. „Managanese and dicopper complexes for bioinspired oxidation reactions: catalytic and mechanistic studies on C-H and C=C oxidations“. Doctoral thesis, Universitat de Girona, 2011. http://hdl.handle.net/10803/78940.

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Enzymes are high-weight molecules which catalyze most of the metabolic processes in living organisms. Very often, these proteins contain one or more 1st row transition metal ions in their active center (Fe, Cu, Co, Mn, Zn, etc.), and are known as metalloenzymes or metalloproteins. Among these, metalloenzymes that activate molecular oxygen and use it as terminal oxidant stand out because of the wide range of catalyzed reactions and their exquisite selectivity. In this PhD dissertation we develop low-weight synthetic bioinspired complexes that can mimic structural and/or functional features of the active center of oxigenases. In the first part, we describe the use of unsymmetric dinuclear Cu complexes which are capable of performing the oxidation of phenols and phenolates in a analogous manner of the tyrosinase protein. In the second part, we describe the use of mononuclear manganese complexes in the oxidation of alcanes and alquenes.
Els enzims són molècules d’elevat pes molecular que catalitzen la majoria de processos metabòlics en els éssers vius. Sovint aquestes proteïnes contenen un o diversos ions metàl•lics de la 1a sèrie de transició en el seu centre actiu (Fe, Cu, Co, Mn, Zn, etc.), essent anomenats metal•loenzims o metal•loproteïnes. D’aquests, els metal•loenzims que activen la molècula d’oxigen i l’utilitzen com a oxidant ressalten per la varietat de reaccions catalitzades i la seva exquisida selectivitat. En aquesta tesi doctoral, desenvolupem complexos de baix pes molecular que puguin mimetitzar estructural i/o funcionalment els centres actius de les oxigenases. En una primera part, es descriu la utilització de complexos assimètrics dinuclears de Cu capaços de dur a terme l'oxidació de fenols i fenolats de manera similar a la proteïna tirosinasa. En una segona part, es descriu l'ús de complexos mononuclears de manganès per a l'oxidació d'alcans i alquens.

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13

Crawford, Andrew. „Catalytic borylation of C-H bonds : a route to photophysically interesting pyrene derivatives“. Thesis, Durham University, 2011. http://etheses.dur.ac.uk/663/.

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Pyrene derivatives have found use in a wide range of applications that make use of the unique structural, optical and charge-transfer properties of pyrene. Nearly all pyrene derivatives are substituted at the 1-, 3-, 6- and 8-positions, i.e. the sites of electrophilic aromatic substitution. In contrast, derivatives substituted at the 2- and 2,7-postions of pyrene are rare, as their syntheses involve laborious multistep processes. Such derivatives are of interest because they retain the long axis of symmetry and display unusual photophysical properties. Using the regiospecific direct C-H borylation of pyrene with an Ir-based catalyst, prepared in situ via reaction of [Ir(OMe)COD]2 with 4,4’-di-tert-butyl-2,2’-bipyridine, 2,7-bis(Bpin)pyrene 1 and 2-(Bpin)pyrene 2 (pin = OCMe2CMe2O) were synthesized. Straightforward derivatization strategies, converted 1 and 2 into nominally nucleophilic and electrophilic pyrene derivatives, which were further utilized in Suzuki-Miyaura, Sonogashira, Buchwald-Hartwig and Negishi cross-coupling reactions. Using this methodology, a library of 2- and 2,7-substituted pyrenes bearing donor and acceptor groups, including aryl, ethynyl, arylethynyl, alkyl, hydroxy, alkoxy, diarylamino, carboxylic acid and diarylboryl derivatives, was prepared. The solid-state structures of several derivatives obtained by single-crystal X-ray diffraction revealed a diverse range of structures and packing modes. The influence of the substitution position and the nature of the substituent upon pyrene was investigated in a detailed photophysical study. The existence of nodal planes passing through the 2- and 7-positions, perpendicular to the molecular plane, in both the HOMO and LUMO of pyrene accounts for the differing photophysical behaviour of derivatives substituted at 2- and 2,7-positions from those substituted at the 1-position. Finally, the applicability of iridium-catalysed C-H borylation and metal-catalyzed cross-coupling is further demonstrated on a range of interesting substrates.

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14

Chappell, Benjamin Graham Neil. „A general catalytic β-C-H carbonylation of aliphatic amines to β-lactams“. Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/274756.

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Carbonyl compounds are of central importance to organic chemistry and their reactions have been described as the ‘backbone of organic synthesis’. Over recent decades, palladium-catalysed C–H carbonylation reactions have emerged as a powerful means of introducing carbonyl motifs to organic molecules. This thesis describes the development of a general C–H carbonylation reaction of secondary aliphatic amines, which provides facile access to synthetically useful β-lactam products. The first part of the thesis explores the scope and limitations of this reaction. Whilst previous C(sp3)–H carbonylation methodologies were restricted to ‘Type F’ secondary aliphatic amines, the reaction described in this thesis was found to be broadly applicable all structural sub-classes of secondary aliphatic amine. Furthermore, the reaction was found to be remarkably tolerant of functional groups, even those that commonly cause issues in palladium-catalysed C–H activation reactions such as heteroaromatics and thioethers. The second part of this thesis investigates the mechanism of this C–H carbonylation reaction. Interestingly, the reaction was found not to proceed via a traditional C–H carbonylation mechanism comprising of C–H activation, 1,1-migratory carbon monoxide insertion and reductive elimination. Instead, a new mechanistic paradigm for palladium-catalysed C–H carbonylation is proposed, which invokes a putative ‘palladium anhydride’ intermediate. A series of DFT calculations and experiments were conducted in order to support this mechanistic proposal. The work described within this PhD thesis was published in Science.

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15

Ishibashi, Aoi. „Synthesis and Transformation of Organoboronic Acids Using Boron-Modifying Strategy for Catalytic C-H Functionalization“. Kyoto University, 2017. http://hdl.handle.net/2433/225960.

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16

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.

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17

Olsson, Vilhelm. „Development of New Synthetic Routes to Organoboronates by Catalytic Allylic Substitution and C-H bond Functionalization“. Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-27753.

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This thesis describes the development of new catalytic methods for the synthesis and application of organometallic reagents, mainly focusing on allylboronic acid derivatives. Thus, palladium pincer-complex catalysis has been applied for extending the scope of palladiumcatalyzed borylation reactions in the synthesis of regio- and stereodefined functionalized allylboronic acid derivatives. These novel allylboronic acids were also employed as substrates in palladium catalyzed regioselective coupling reactions with iodobenzenes. We have also developed a new one-pot sequence based on preparation of allyl- and vinylboronates via catalytic carbon-hydrogen bond activation/borylation reactions. The synthetic scope of the reaction as well as mechanistic studies on the borylation process are presented. Finally, the synthesis of new chiral palladium pincer-complexes is described. These species were employed as catalysts in asymmetric electrophilic allyation of imines.

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18

Dantignana, Valeria. „Bioinspired metal-based oxidants: selectivity in catalytic hydroxylation of aliphatic C-H bonds and insight into the reactivity of oxoiron species“. Doctoral thesis, Universitat de Girona, 2020. http://hdl.handle.net/10803/671447.

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Selective oxidation of C-H bonds is an important reaction, as it can disclose novel synthetic strategies to get functionalized products through efficient paths. Nonetheless, due to the inert character of C-H bonds, the use of powerful oxidants is needed. In addition, achieving selectivity in such reactions is difficult. In that regard, nature can be taken as inspiration, since oxidation reactions are efficiently and selectively performed by iron-dependent oxygenases. Thus, in order to develop novel methodologies, bioinspired complexes have been explored as oxidation catalysts. In this line, in this thesis hydroxylation of C-H bonds catalyzed by bioinspired iron and manganese complexes has been first investigated. Subsequently, being mechanistic understanding important for the design of efficient catalysts, high-valent oxoiron compounds have been investigated to deeper comprehend how to modulate their oxidative ability
La oxidación selectiva de enlaces C-H es una reacción importante ya que permite el desarrollo de nuevas estrategias para la síntesis de productos funcionalizados mediante procesos altamente eficientes. No obstante, debido al carácter inerte del enlace C-H, se necesitan oxidantes muy fuertes. Además, conseguir altas selectividades en estas reacciones es especialmente complicado. En este sentido, la naturaleza se puede utilitzar como fuente de inspiración ya que en los sistemas biológicos este tipo de reacciones son catalizadas con alta eficiencia y selectividad por oxigenasas dependientes de hierro. Así pues, el desarrollo de nuevas metodologías sintéticas se basa en el uso de complejos bioinspirados como catalizadores de oxidación. En esta tesis se estudia en primer lugar el uso de complejos bioinspirados de hierro y manganeso para la hidroxilación de enlaces C-H. Posteriormente se investigan compuestos hierro-oxo de alta valencia para comprender mejor sus propiedades oxidativas y poder diseñar así catalizadores más eficientes

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19

Thu, Hung-yat, und 杜鴻溢. „Catalytic C-H bond functionalization reactions catalyzed by rhodium(III) porphyrin, palladium(II) and platinum(II) acetatecomplexes“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B38798268.

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20

Torigoe, Takeru. „New Molecular Transformations Based on Iridium-Catalyzed Activation of C(sp3)-H Bonds“. 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225636.

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21

Thu, Hung-yat. „Catalytic C-H bond functionalization reactions catalyzed by rhodium(III) porphyrin, palladium(II) and platinum(II) acetate complexes“. View the Table of Contents & Abstract, 2006. http://sunzi.lib.hku.hk/hkuto/record/B38027872.

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22

Alam, Rauful. „Catalytic Regio- and Stereoselective Reactions for the Synthesis of Allylic and Homoallylic Compounds“. Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-121757.

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This thesis is focused on two main areas of organic synthesis, palladium-catalyzed functionalization of alkenes and allylic alcohols, as well as development of new allylboration reactions. We have developed a palladium-catalyzed selective allylic trifluoroacetoxylation reaction based on C−H functionalization. Allylic trifluoroacetates were synthesized from functionalized olefins under oxidative conditions. The reactions proceed under mild conditions with a high level of diastereoselectivity. Mechanistic studies of the allylic C−H trifluoroacetoxylation indicate that the reaction proceeds via (η3-allyl)palladium(IV) intermediate. Palladium-catalyzed regio- and stereoselective synthesis of allylboronic acids from allylic alcohols has been demonstrated. Diboronic acid B2(OH)4 was used as the boron source in this process. The reactivity of the allylboronic acids were studied in three types of allylboration reactions: allylboration of ketones, imines and acyl hydrazones. All three processes are conducted under mild conditions without any additives. The reactions proceeded with remarkably high regio- and stereoselectivity. An asymmetric version of the allylboration of ketones was also developed. In this process chiral BINOL derivatives were used as catalysts. The reaction using γ-disubstituted allylboronic acids and various aromatic and aliphatic ketones afforded homoallylic alcohols bearing two adjacent quaternary stereocenters with excellent regio-, diastereo- and enantioselectivity (up to 97:3 er) in high yield. The stereoselectivity in the allylboration reactions could be rationalized on the basis of the Zimmerman-Traxler TS model.

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23

Rosa, Lourenço de Pina Cardoso Bernardo. „Structure of cationic CNHC,Calkyl nickelacycles and their activity in the catalytic functionalization of the C–H bonds of azoles“. Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF033/document.

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Cette thèse développe l'étude des complexes de nickel(II) porteurs de ligands carbènes N hétérocycliques (NHC) selon deux axes: la synthèse et la caractérisation de complexes nickelacycliques avec un ligand chélatant carbone-carbone (CNHC, Calkyl); et leur activité catalytique dans la construction des liaisons carbone-carbone (Csp2–Csp2/Csp3) des 1-chalcogènes-azoles par fonctionnalisation des liaisons carbone-hydrogène (C–H). Une série de produits d'addition d'acétonitrile métallacycliques CNHC,Calkyl-Ni(II) cationiques a été synthétisée par élimination d'un ligand cyclopentadiényle des nickelacycles demi-sandwich a 18 électrons de valence parents. Il a été déterminé que les complexes cationiques existaient en tant qu'espèce Ni(II) à 14 électrons de valence en forme de T, insaturée de manière coordonnée et électronique, à l'état solide. L'application de ces nouveaux complexes au couplage croisé du benzothiazole avec les iodoarènes s'est avérée une stratégie efficace dans la formation des liaisons Csp2–Csp2, par la combinaison d'un échafaudage métallacyclique stabilisant avec des ligands labiles. La découverte d'une espèce demi sandwich Ni(II)-(NHC)-(benzothiazolyle) inactif dans l'arylation du benzothiazole, mais actif dans le couplage du benzothiazole avec les iodoalcanes, constitue le premier exemple de construction des liaisons Csp2–Csp3 du benzothiazole avec un catalyseur Ni(II)-NHC
This thesis develops the study of nickel(II) complexes bearing N-heterocyclic carbene ligands (NHC) in two axes: the synthesis and characterization of nickelacyclic complexes with a carbon-carbon chelating ligand (CNHC,Calkyl); and their catalytic activity in the construction of carbon-carbon bonds (Csp2–Csp2/Csp3) of 1-chalcogene-azoles by carbon-hydrogen (C–H) bond functionalization. A series of cationic CNHC,Calkyl-Ni(II) metallacyclic acetonitrile adducts was synthetized by the removal of a cyclopentadienyl ligand from parent 18 valence electron half-sandwich nickelacycles. The cationic complexes were determined to exist as rare coordinatively and electronically unsaturated T-shaped 14 valence electron Ni(II) species, in the solid state. Application of these new complexes to the cross-coupling of benzothiazole with iodoarenes proved to be a successful strategy in Csp2–Csp2 bond formation, by the combination of a stabilizing metallacyclic scaffold with labile ligands. The discovery of a half-sandwich Ni(II)-(NHC)-(benzothiazolyl) species, inactive in the arylation of benzothiazole, but active for the cross-coupling of benzothiazole with iodoalkanes shows the first example of benzothiazole Csp2–Csp3 bond construction with a Ni(II)-NHC catalyst

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Biafora, Agostino [Verfasser], und Lukas J. [Akademischer Betreuer] Gooßen. „Sustainable Methods for the Catalytic Regioselective Transformation of Aromatic Carboxylic Acids via C-COOH and C-H Bond Cleavage / Agostino Biafora ; Betreuer: Lukas J. Gooßen“. Kaiserslautern : Technische Universität Kaiserslautern, 2017. http://d-nb.info/1140760912/34.

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25

Sasaki, Ikuo. „Development of Novel Synthetic Methods of Organosilicon Compounds Utilizing Silicon-Containing Reactive Intermediates“. Kyoto University, 2020. http://hdl.handle.net/2433/253508.

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26

Chen, Gong. „Studies on Chemo- and Site-Selective C-H Amination of Aniline and Phenol Derivatives with Dirhodium Catalysts and Catalytic Asymmetric Synthesis of Inherently Chiral Calixarenes“. Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263599.

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27

Prat, Casellas Irene. „Bioinspired non-heme iron catalysts for challenging oxidative transformations: mechanistic studies and catalytic applications on selective alkane hydroxylation and alkene cis-dihydroxilation“. Doctoral thesis, Universitat de Girona, 2013. http://hdl.handle.net/10803/117778.

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The functionalization of hydrocarbons in a sustainable manner is one of the main challenges for chemists. Their abundance in nature as natural gas or crude oil makes them the most convenient chemical feedstock. The oxidation of hydrocarbons is one of the most interesting reactions, because the introduction of an oxygen atom introduces functionality in these molecules, increasing their value as reagents for further chemical transformation. However, these reactions are fundamentally difficult due to the low reactivity of alkyl C-H bonds. Current available methodologies involve highly reactive-oxidizing reagents, high temperatures and long-time reactions in order to overcome this lack of reactivity. These harsh conditions introduce drawbacks in terms of chemo- and regioselectivity, essential to produce synthetic valuable products. An important step forward is the development of one-step oxidation methodologies, allowing the oxidation of C-H and C=C with high regio- and stereoselectivity. Natural systems, such as iron enzymes, are capable of perform this chemistry with high selectivity and efficiency. Iron is the most abundant metallic element in the earth and is essential for live. In addition, this lack of toxicity makes it and attractive material to substitute more toxic and expensive metals currently used. One of the main objective of this thesis is design of iron complexes that mimics the structure and function of these natural enzymes with the aim of find new methodologies for the selective C-H and C=C bond oxidation using green conditions. Furthermore, the study of these compounds could give useful information about the oxidation mechanisms operating in oxygenase enzymes. The results obtained in this thesis clarify the mechanism by which the oxidation of the C-H bond with retention of stereochemistry takes place at a mononuclear non-heme iron site, and evidence the formation of a high valent iron (V) capable of perform the cis-dihydroxylation of alkenes. Furthermore, a new complex is described as an efficient and selective catalyst capable of performing this chemistry in a scale amenable for synthetic applications
La funcionalització d'hidrocarburs de manera sostenible i eficaç és un dels principals reptes per la química moderna, degut a que la seva abundància natural els fa una important matèria primera. L'oxidació d'hidrocarburs és una de les reaccions més interessants, ja que la introducció d’un àtom d’oxigen en l’estructura d’un hidrocarburs li confereix funcionalitat química, fa augmentar el seu valor i els converteix en reactius adients per subseqüents transformacions químiques. No obstant això, aquestes reaccions són difícils a causa de la inherent baixa reactivitat dels hidrocarburs. Les metodologies actualment disponibles impliquen la utilització d’espècies altament oxidants i tòxiques, altes temperatures i llargs temps de reacció per tal de superar aquesta manca de reactivitat. Aquestes condicions extremes eviten que la química es pugui dur a terme de manera selectiva, fet essencial per produir productes d’alt valor sintètic. Un avanç important és el desenvolupament de metodologies de reacció suaus que permetin l'oxidació d'enllaços C-H i C=C amb alta regio- i estereoselectivitat. Els sistemes naturals, com ara enzims de ferro, són capaços de realitzar aquesta química. El ferro és l’element metàl•lic més abundant a la terra i és clau per nombrosos processos vitals, a més la seva baixa toxicitat el fa un atractiu material per substituir els elements de segona i tercera seria de transició més cars i tòxics emprats actualment. Un dels principals objectius d’aquesta tesi és dissenyar catalitzadors de ferro que imiten l’estructura i la funció dels enzims naturals per tal de trobar una nova metodologia que permeti l'oxidació selectiva d'enllaços C-H i C=C utilitzant condicions suaus i mediambientalment més benignes que les metodologies tradicionals. A més, l’estudi d’aquests sistemes pot donar informació útil sobre el mecanisme d’oxidació del propi enzim. Els resultats obtinguts en aquesta tesi aclareixen el mecanisme pel qual es duu a terme la hidroxilació de l’enllaç C-H amb retenció de la estereoselectivitat en centres mononuclears de ferro, i evidencien la formació d’una espècie de ferro (V) d’alt estat d’oxidació capaç de catalitzar la cis-dihidroxilació d’alquens. A més a més, es descobreix un catalitzador eficient i selectiu capaç de dur a terme aquesta química en condicions d’escala preparativa

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Grimster, Neil Patrick. „New strategies for chemical synthesis : 1) Development of a palladium-catalyzed direct C-H alkenylation of indoles by solvent-controlled regioselective C-H bond functionalisation; 2) Studies towards the development of a catalytic diastereoselective [3,3] sigmatropic rearrangement at ambient temperature“. Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612869.

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29

Duchane, Christine Marie. „Synthesis, antimicrobial activity, and catalytic activity of rhodium and iridium piano stool complexes: Teaching an old dog new tricks“. Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/101016.

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This dissertation describes the synthesis, antimicrobial properties, and catalytic activity of a variety of eta5-ligand rhodium and iridium complexes. Cp*RM(beta-diketonato)Cl (Cp*R = R-substituted tetramethylcyclopentadienyl ligand) complexes were found to have selective activity against Mycobacterium smegmatis, with activity highly dependent upon the substituents on the Cp*R ligand as well as on the beta-diketonato ligand. These complexes were synthesized in good yield from the reaction of the chloro bridged dimers ([Cp*RMCl2]2) with the desired beta-diketonato ligand under basic conditions. All complexes were fully characterized by 1H and 13C NMR. Twenty single crystal X-ray structures were solved. The success of these syntheses led to investigation of another beta-diketonato ligand: 1,1,1,5,5,5-hexafluoroacetylacetonate (hfac). Though many metal complexes of this ligand are known, reaction with [Cp*MCl2]2 did not yield the desired Cp*M(hfac)Cl complexes. Instead, a variety of products were obtained, three of which were characterized crystallographically. The most interesting structure featured a non-coordinating trifluoroacetate (TFA) anion and a [Cp*Ir]3Na1O4 cubane structure, which is an unprecedented and highly unusual arrangement for iridium. Attempts to synthesize this cluster rationally through reactions of [Cp*IrCl2]2 with TFA yielded instead a chloro bridged [Cp*IrCl(TFA)] dimer. Reaction of [Cp*MCl2]2 with 1,1,1-trifluoroacetylacetonate (tfac) yielded the expected Cp*M(tfac)Cl complex, indicating that the problem lies with using hfac as a ligand for Cp*M(III) complexes. Finally, the indenyl effect was investigated for the oxidative annulation of 2-phenylimidazole with 1-phenyl-1-propyne catalyzed by a series of methyl-substituted [(indenyl)RhCl2] dimers. [(Ind*)RhCl2]2 was found to have significantly greater activity than [Cp*RhCl2]2 (100% vs. 51%). Two plausible catalytic cycles were proposed, one of which invokes a ring slip transition state. Though it is unclear if the "indenyl effect" is responsible for this differing activity, it is certainly apparent that using an indenyl ligand has a notable effect in this catalytic reaction. Cyclometalation was also investigated stoichiometrically for 2-phenyl-1H-imidazole and 1-phenylpyrazole and found to proceed readily for [(Ind*)RhCl2]2. Additionally, the crystallographic structure of a Rh+ /Rh– ionic pair was solved. Ionic pairs such as this are rarely found in the literature.
Doctor of Philosophy

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Potukuchi, Harish Kumar [Verfasser], Lutz [Akademischer Betreuer] Ackermann und Dietmar [Akademischer Betreuer] Stalke. „Catalytic syntheses and copper- or ruthenium-catalyzed direct C H bond arylations of (hetero)arenes / Harish Kumar Potukuchi. Gutachter: Lutz Ackermann ; Dietmar Stalke. Betreuer: Lutz Ackermann“. Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2011. http://d-nb.info/1043939148/34.

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Sun, Ho-Yan. „Studies on the Mechanism of Direct Arylation of Pyridine N oxides: Evidence for the Essential Involvement of Acetate from the Pd(OAc)2 Pre-Catalyst at the C-H Bond Cleaving Step“. Thesis, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/19760.

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Detailed mechanistic studies on the palladium-catalyzed direct arylation of pyridine N-oxides are presented. The order of each reaction component is determined to provide a general mechanistic picture. The C-H bond cleaving step is examined in further detail through computational studies, and the calculated results are in support of an inner-sphere concerted metallation-deprotonation (CMD) pathway. Competition experiments were conducted using N-oxides of varying electronic characters, and results revealed an enhancement of rate when using a more electron-deficient species which is in support of a CMD transition state. The effect of base on reaction rate was also examined and it was found that a carboxylate base was required for the reaction to proceed. This led to the conclusion that Pd(OAc)2 plays a pivotal role in the reaction mechanism as more than merely a pre-catalyst, but as a source of acetate base required for the C-H bond cleavage step.

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Dietl, Nicolas Paul Richard [Verfasser], und Helmut [Akademischer Betreuer] Schwarz. „Gaseous Oxo-Clusters as Model Systems for C-H Bond Activation and Oxidation Processes – Towards a Better Understanding of Catalytic Mechanisms / Nicolas Paul Richard Dietl. Betreuer: Helmut Schwarz“. Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2013. http://d-nb.info/1032313269/34.

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Coetzee, Jacorien. „Towards new catalytic systems for the formation of methyl methacrylate from methyl propanoate“. Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/2585.

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The two stage Lucite Alpha Process for the industrial manufacturing of methyl methacrylate (MMA) represents one of the most efficient technologies currently available for the large scale production of this important chemical commodity. The second stage of this process, which involves the condensation of methyl propanoate (MeP) with formaldehyde over a heterogeneous fixed bed catalyst, however, still shows great scope for improvement. Herein the development of a novel homogeneous catalytic system that would promote the condensation of either propanoic acid or MeP with formaldehyde is explored. Since C–C bond forming reactions which proceed via C–H activation pathways typically display high atom efficiency, our efforts were particularly focussed on employing a functionalisation strategy that is mediated by C–H activation. In the case of propanoic acid, the possibility of achieving regioselective α-methylenation by linking the substrate to phosphorus was evaluated. Thus, a series of acyloxyphosphines and acylphosphites derived from either propionic acid or phenylacetic acid was prepared and, where stability allowed, fully characterised. Some of the resultant simple mixed anhydrides posed problems relating to their stability, and the stabilisation of such ligand systems by using electronic and / or steric effects was therefore explored. In addition, the coordination chemistry and in solution behaviour of Rh(I) and Ru(II) complexes containing these ligands was examined. Similar to the free ligands, complexes derived from these mixed anhydrides rearranged in solution via a number of decomposition pathways, with the specific pathway dependent on the nature of the auxiliary ligands. For most of these complexes, however, ligand decarbonylation was the route of preference for decomposition. Despite the instability of these complexes, a selection of Rh(I) mixed anhydride complexes were assessed for their potential as C-H activation catalysts in reactions aimed at the α-methylenation of saturated carboxylic acids. Furthermore, the stabilisation of Rh(I) mixed anhydride complexes with chelating auxilary ligands, such as bisphosphines or N-substituted diphosphinoamines, was explored. In particular, a series of new Rh(I) mixed anhydride complexes containing dppe, dppb and dppbz as secondary ligands were prepared and the effects of these secondary ligands on the in solution stability of these complexes assessed. As MeP represents the final product in the first stage of the Alpha process and not propanoic acid, the utilisation of PNP iridium pincer complexes in the regioselective sp³ C–H activation of MeP and related esters was also examined. The factors that govern the regioselectivity of such reactions were of great interest to us and, in particular, the effects of water on the reactivity and regioselectivity of these reactions were explored. For MeP, preferential C–H activation of the methoxy group was found to proceed under anhydrous conditions and the catalytic functionalisation of this site with ethene using this activation approach was considered. Formaldehyde, employed in the second stage of the Alpha process, is a difficult substance to manufacture and handle, especially on a large scale. A preliminary study on the in situ production of anhydrous formaldehyde via the catalytic dehydrogenation of methanol was therefore performed. During this study, catalytic systems based on carbonate salts and / or transition metal complexes were considered. In the hope of reducing the number of steps required in the production of MMA, a new one-pot cascade reaction for the indirect α-methylenation of MeP with methanol was developed. Although the production of MMA using this system only proceeded with low efficiency, the obtained results serve as an important proof of concept for future developments in this area. Finally, the capacity of a series of simple bases to catalyse the condensation of MeP with formaldehyde was assessed as part of a fundamental study directed towards determining the factors that govern the efficiency of this reaction. In addition, the extent to which each base effects the deprotonation in the α-position of MeP was determined with the aid of deuterium labelling experiments. Similarly, using sodium propanoate as model base a rough estimate of the kinetics of deprotonation could be made based on the degree of deuterium incorporation over time. These studies suggested that the low efficiency of this condensation reaction is not caused by ineffective deprotonation but rather by the weak nucleophilicity of the generated carbanion. For this reason, attempts to increase the electrophilicity of formaldehyde through Mannich-type condensations reactions involving secondary amine and carboxylic acid additives were made.

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Haslinger, Stefan [Verfasser], Fritz Elmar [Akademischer Betreuer] Kühn, Ulrich K. [Akademischer Betreuer] Heiz, Richard W. [Akademischer Betreuer] Fischer und Jean-Marie [Akademischer Betreuer] Basset. „Bioinspired Iron N-Heterocyclic Carbene Complexes in C–H Bond Oxidation: Reactivity, Electronic Properties, and Catalytic Activity / Stefan Haslinger. Betreuer: Fritz Elmar Kühn. Gutachter: Ulrich K. Heiz ; Richard W. Fischer ; Fritz Elmar Kühn ; Jean-Marie Basset“. München : Universitätsbibliothek der TU München, 2015. http://d-nb.info/1080299270/34.

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35

Zhang, Shoukun. „Selective C–H Activation by Ruthenium(II) Carboxylate and Nickelaelectro-Catalysis“. Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2021. http://hdl.handle.net/21.11130/00-1735-0000-0005-155B-E.

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36

Moselage, Marc Philipp. „C-H and C-C Activation by Cobalt and Ruthenium Catalysis“. Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2017. http://hdl.handle.net/11858/00-1735-0000-0023-3FB2-6.

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37

Nekkanti, Yelha Phani Kumar. „Ruthenium(II) biscarboxylate-Catalyzed C(sp2)-H and C(sp3)-H Functionalizations by Chelation Assistance“. Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2016. http://hdl.handle.net/11858/00-1735-0000-002B-7CCA-E.

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38

Barzen, Lars [Verfasser], und Gereon [Akademischer Betreuer] Niedner-Schatteburg. „Metal cluster aggregates of the composition Nbn+/-, Con+/- and [ConPtm]+/- as model systems for catalytic C-H activation and structural determination of selected metal peptide complexes of the molecules aspartame (Asp-PheOMe) and Asp-Phe / Lars Barzen. Betreuer: Gereon Niedner-Schatteburg“. Kaiserslautern : Technische Universität Kaiserslautern, 2013. http://d-nb.info/1036129616/34.

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Bencivenga, Nicholas Ernest. „Enantioselective nickel catalysis : exploiting activated C-H bonds“. Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/73437.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 26-27).
A method for the nickel-catalyzed cross-coupling between benzoxazole and secondary halides was explored. This method was to make use of the activated C-H bond found in benzoxazole at the 2-position to generate the nucleophilic species in situ. After an extensive survey of parameters no such method could be found. However, it was found that copper(I) salts promoted the coupling of benzoxazole and benzylic bromides in high yield, albeit in a racemic fashion. Additionally a method to cross-couple terminal alkynes with secondary halides employing nickel-catalysis was explored. After surveying a number of alkynylmetal species, generated in situ, alkynyl borates were found to cross-couple with allylic chlorides to furnish product with the best enantioselectivity (enantiomeric excess ca. 70%), however in low yield.
by Nicholas Ernest Bencivenga.
S.M.

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Müller, Thomas. „C-H Activation by Nickel and Iron Catalysis“. Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://hdl.handle.net/21.11130/00-1735-0000-0003-C189-8.

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41

Korvorapun, Korkit. „Site-Selectivity in Ruthenium-Catalyzed C–H and C–C Activations“. Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://hdl.handle.net/21.11130/00-1735-0000-0005-148C-7.

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Zhang, Yuyang. „Functionalization of alpha- and beta-Amino C-H Bonds Using Cooperative Catalysis:“. Thesis, Boston College, 2020. http://hdl.handle.net/2345/bc-ir:108932.

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Thesis advisor: Masayuki Wasa
Cooperative catalysis has been developed for transformations where at least two reactants are activated in situ by acid or base sensitive catalysts to form the reactive species and subsequent bond formation leads to desired product. This thesis focuses on the development of ɑ-amino C-H alkynylation and β-amino C-H deuteration through the use of cooperative catalysts. In the alkynylation reaction, N-alkylamines and trimethylsilyl substituted alkynes were used to synthesize propargylamines by the cooperative actions of Lewis acid catalysts, B(C₆F₅)₃ and copper complex. The reaction between in situ generated iminium ion and copper alkyne complex afforded the product. The method is applicable to the late-stage functionalization of bioactive amine drug molecules and has been shown to tolerate different functional groups on trimethylsilyl-substituted alkynes. In addition, an enantioselective and diastereoselective version of the method was also developed through the use of chiral copper complex. In the second part, selective deuteration of β-amino C-H bonds of various acylic and cyclic alkyl amines will be introduced. B(C₆F₅)₃ and Brønsted base work cooperatively to afford enamine and deuterated ammonium ion as reactive intermediate. Deuteration of enamine at the β-position and hydride reduction at the ɑ-position gave the selectively deuterated products. Acetone-d₆ was the found to be the optimal source of deuterium. This method was able to incorporate deuterium atoms up to 99% and can be applied in a gram scale reaction without compromising the yield or d-incorporation level
Thesis (MS) — Boston College, 2020
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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Liu, Weiping. „Ruthenium- and Manganese-Catalyzed C−O and C−C Formation via C−H Activation“. Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2016. http://hdl.handle.net/11858/00-1735-0000-0028-8771-3.

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Da, Cruz Ana Cristina Fernandes. „C-H bonds as functional groups for palladium catalysis“. Thesis, University of Bath, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.586169.

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Hennessy, Elisabeth Therese. „C-H Amination Catalysis from High-Spin Ferrous Complexes“. Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11186.

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The C-H amination and olefin aziridination chemistry of iron supported by dipyrromethene ligands (RLAr, L=1,9-R2-5-aryldipyrromethene, R = Mes, 2,4,6-Ph3C6H2, tBu, Ad, 10-camphoryl, Ar = Mes, 2,4,6-Cl3C6H2) was explored. The weak-field, pyrrole-based dipyrrinato ligand was designed to generate an electrophilic, high-spin metal center capable of accessing high valent reactive intermediates in the presence of organic azides. Isolation of the reactive intermediate in combination with a series of mechanistic experiments suggest the N-group transfer chemistry proceeds through a rapid, single-electron pathway and maintains an overall S=2 electronic configuration throughout the catalytic cycle. We have established the catalysts' strong preference for allylic amination over aziridination with olefin containing substrates. Aziridination is limited to styrenyl substrates without allylic C-H bonds, while allylic amination has been demonstrated with both cyclic and linear aliphatic alkenes. Notably, the functionalization of &alpha-olefins to linear allylic amines occurs with outstanding regioselectivity.
Chemistry and Chemical Biology

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Loup, Joachim. „Selectivity Control in 3d Transition Metal-Catalyzed C–H Activation“. Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://hdl.handle.net/21.11130/00-1735-0000-0003-C19E-1.

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Liu, Po Man. „Ruthenium catalysed C-H functionalisation of heteroaromatics“. Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.665404.

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Two methods of C-H functionalisation of sp2 C-H bonds via ruthenium catalysis have been developed in this thesis. The first methodology is the preparation of meta-sulfonated heteroaromatics. Individual substrate optimisations were performed on various nitrogen containing heteroaromatics such as 2-phenylpyridine, 1-phenylpyrazole and benzo[h]quinoline. It was discovered that 2-phenylpyridine was the best substrate for C-H sulfonation with aryl sulfonyl chlorides and gave yields of 4 – 63% and provided functional handles allowing for further synthetic manipulations. The second methodology developed is a ruthenium(II) catalysed ortho-C-H acylation of heteroaromatics. Initial optimisation was performed on 2-phenylpyridine with ortho-toluoyl chloride for C-H acylation and it was found tricyclohexylphosphine was the best ligand for this reaction. Unfortunately, the scope of this reaction is limited, as only a couple of aryl acid chlorides were compatible for the acylation of 2-phenylpyridine. This methodology was then applied to 1-phenylpyrazole and demonstrated the first example of C-H acylation of 1-phenylpyrazole with acid chloride as the coupling partner. C-H acylation of 1-phenylpyrazole is more versatile than 2-phenylpyridine, as the reaction scope is much broader. Various aryl and alkyl acid chlorides were compatible for the acylation of 1-phenylpyrazole derivatives and gave yields of 4 – 91%. Sterically hindered acid chlorides provided the higher yields, which is indicative of a steric acceleration during the reductive elimination step. Ruthenium-substrate complexes were synthesised and employed in stoichiometric experiments under the meta-sulfonation and ortho-acylation conditions independently, to attempt to elucidate the mechanistic pathways of these two reactions. 1H NMR spectroscopy on the meta-sulfonations of 1-phenylpyrazole and benzo[h]quinoline complexes indicated the formation of sulfonated ruthenium-substrate complexes, where the sulfone is substituted para to the ruthenium-carbon bond. C-H activation of 1-phenylpyrazole with a ruthenium-phosphine complex was attempted, and found it was difficult to synthesise the C-H activated substrate-ruthenium complex in the presence of phosphine ligands.

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Merkert, Christine [Verfasser], und Gereon [Akademischer Betreuer] Niedner-Schatteburg. „Metal cluster aggregates of the composition Fen+/, Con+/-, Nin+/- and [ConMm]+/- (M: Au, Rh and Pt) as model systems for catalytic C-H activation and structural determination of ionic dicarboxylic acids as model system for intramolecular hydrogen bonding / Christine Merkert. Betreuer: Gereon Niedner-Schatteburg“. Kaiserslautern : Technische Universität Kaiserslautern, 2014. http://d-nb.info/1051310377/34.

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Wang, Anqi. „Cu-Catalyzed Amination of sp3 C-H Bonds“. Digital WPI, 2018. https://digitalcommons.wpi.edu/etd-dissertations/509.

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Presented herein is the development, optimization and mechanistic investigation of an Cu catalytic system for the oxidation of sp 3 C-H bond of simple arenes to form C-N bond in a direct manner. Due to the prevalence of nitrogen containing molecules among biologically active synthetic and natural compounds, synthetic chemists have always been motivated to develop new efficient ways to directly transform ubiquitous carbonhydrogen (C-H) bonds into carbon- nitrogen (C-N) bonds. Recent advances in transition metal catalyzed C-H amination has demonstrated that it is not only possible but also practical to functionalize C-H bonds that are often considered inert in one step, circumventing more classical, sequential functional group interconversion approaches. Existing catalytic systems that promote the transition metal-catalyzed, amination of sp 3 C-H bonds displayed certain limitations, especially the lack of built-in versatility and stability in their amination reagents. To overcome these drawbacks of these existing catalytic system, our group developed a new Cu amination protocol that deployed versatile hydroxylamine-based with general structure RSO 2 NH-OAc as amination reagents. Although the reactivity of the catalytic system ranges from moderate to good, the catalytic system provided promising results using simple arene substrates. Further detailed mechanistic studies revealed that the reaction undergoes an unprecedented two subsequent cycles divided by a major intermediate PhCH 2 (NTsOAc). The proposed mechanism is consistent with radical clock experiments, observed reaction profiles, the need for excess of substrate, and the documented role of the ligand in the catalytic system. The exciting proposed mechanism led to a new type of copper catalyzed amination reaction using N- fluorobenzenesulfonimide (NFSI) as oxidant, which overcomes the need to use an excess of substrate. A wide range of unactivated amines HNR 1 R 2 , including sulfonamide and benzamide, can be used as amine sources, which enables the installation of different nitrogen groups on benzylic sp 3 C-H bond of a variety of substrates in moderate to excellent yield. Moreover, mechanistic experiments and critical analysis of related reactivity in the literature provide insight into the catalytic cycle, resulting in a proposal that details the role of both oxidant and amine source in the new system.

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Sun, G. A. „A study of catalysis by [RuCl(H)(PPh₃)₃] and [η⁵-C₇H₉)RuCl(PPh₃)₂]“. Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242370.

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