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1
Perry, Ian B. (Ian Brooks). « Transition metal-facilitated C-C and C-F bond forming ». Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112449.
Texte intégralRésumé :
Thesis: S.B., Massachusetts Institute of Technology, Department of Chemistry, 2017.Cataloged from PDF version of thesis. "June 2017."
Includes bibliographical references.
Chapter 1. Copper-Catalyzed Asymmetric Addition of Olefin-Derived Nucleophiles to Ketones A copper (I) catalyzed coupling olefins and ketones has been developed for the diastereo- and enantioselective generation of homopropargyl alcohols bearing vicinal stereocenters. This method allows for the generation of enantioenriched tertiary alcohols with a high degree of functional group compatibility. The utility of the process is further illustrated by a large scale synthesis with extremely low catalyst loading as well as the late stage modification of several pharmaceuticals. Chapter 2. Copper-Catalyzed Enantioselective Addition of Styrene-Derived Nucleophiles to Imines We describe the catalytic generation of amines bearing vicinal stereocenters with a moderate degree of diastereoselectivity. The stereoselective hydrocupration of an unactivated olefinic component is followed by nucleophilic addition of the organocuprate to an N-phosphinoyl protected imine. The mild and general process tolerates a broad-range of functionality, and the process was shown to be successful at a gram-scale synthesis. Chapter 3. Palladium-facilitated Regioselective Nucleophilic Fluorination of Aryl and Heteroaryl Halides. The preliminary findings regarding an aryl and heteroaryl halide fluorination process facilitated by palladium as a reagent is described. Stoichiometric studies illustrate the utility of the method in producing aryl fluorides with unprecedented regioselectivity, and preliminary studies into the fluorination of five- and six-membered heteroaryl bromides are described. Halogen atom substitution as a route to irreversible oxidative addition of aryl and heteroaryl halides is discussed. This strategy may serve to facilitate the fluorination of particularly problematic heteroaryl bromide and chloride substrates.
by Ian B. Perry.
S.B.
2
LAUFFER, FRIANT ARMELLE. « De l'ozone aux c. F. C. : approche industrielle ». Nancy 1, 1993. http://www.theses.fr/1993NAN1P073.
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3
Neurrisse, André. « Le Franc C. F. A ». Paris 2, 1987. http://www.theses.fr/1987PA021018.
Texte intégralRésumé :
Monnaie forte ou monnaie faible selon que l'on se refere a l'environnement geographique ou a son statut garanti, le franc c. F. A. Constitue un modele unique de monnaie commune a plusieurs etats. L'analyse de ce phenomene contemporain s'effectue selon trois axes : historique, institutionnel et dynamique. Le milieu monetaire africain presente cette particularite d'offrir en moins d'un siecle un raccourci exemplaire de l'evolution generalement d'ordre millenaire de la forme de l'instrument monetaire. Il n'y a guere, les paleo-monnaies etaient encore en usage et les techniques et institutions monetaires de l'occident industrialise se sont trouvees en situation concurrentielle delicate. Il a fallu les remous economiques et politiques de la deuxieme guerre mondiale pour consacrer un statut institutionnel original. C'est en effet en 1945 que le franc c. F. A. A ete cree, marquant a la fois l'autonomie et la dependance monetaire des territoires interesses. Fidelise a la valeur du franc francais, il a subi dans sa mouvance l'erosion due aux tensions contradictoires du mirage centrifuge de l'autonomie politique et du centralisme economique. Neanmoins il a ete conforte par l'esprit associationniste africain et par l'integration concertee des politiques monetaires. En fait, le franc c. F. A. Tire sa force du concours qu'il apporte au developpement des pays concernes, sa vitalite de la maniere dont, sur la base des preferentialites economiques, il fait fonction de reducteur des divergences economiques. Des lors, la question emerge de cerner les conditions optimales d'existence d'une monnaie commune et de s'interroger, finalement sur l'avenir d'une monnaie europeenne.
4
Rogers, Joshua Peter. « Photoelectron spectroscopy of (C₆F₆)-ₙ and C₆F₆ · I-clusters in a novel instrument ». Thesis, Durham University, 2017. http://etheses.dur.ac.uk/12364/.
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The capabilities of a new photoelectron spectrometer are characterised in the study of (C6F6)n– and (C6F6)I– clusters. The photoelectron spectrometer consists of a series of vacuum chambers that facilitate a molecular beam of gas-phase anions. These anions and clusters are generated at the point of intersection between an electron beam and the supersonic expansion produced by a high temperature Even-Lavie pulsed valve. The anions are extracted orthogonally and mass-separated in a Wiley-McLaren time-of-flight mass spectrometer. The analyte is addressed by a laser pulse produced by either a tuneable nanosecond OPO for one-photon frequency-resolved measurements or a femtosecond pump-probe regime for two-photon time-resolved measurements. The kinetic energy of the resulting photoelectrons are measured in a velocity-map imaging spectrometer. C6F6- is of interest due to the prediction that it ought to host a meta-stable binding mode of the excess electron known as a correlation-bound state (CBS). Similar to other non-valence binding modes, such as the dipole-bound state, this CBS is thought to act as a doorway state in the mechanism of low energy electron capture. The CBS is characterised by a large and diffuse orbital in which the excess electron is bound primarily through charge:induced-dipole interactions with the molecule’s valence orbital system. In the CBS, C6F6- is predicted to adopt a planar geometry like that of the neutral species, in contrast to the buckled geometry adopted when the excess electron occupies a valence orbital. Frequency- and time-resolved measurements of the anion were made in an effort to generate and observe the CBS. Initially, frequency resolved measurements of (C6F6)n– revealed a vertical detachment energy of 1.60 ± 0.07 eV for n = 1, increasing by 200 meV per additional cluster unit up to n = 5. The broad shape of the direct detachment peak confirms the disparity in geometry between the anion and neutral species. However, no evidence of the CBS was evident in these data. In subsequent explorations, an in-situ electron donor was employed to mimic the electron impact process. An I– ion was introduced to the neutral C6F6 molecule to produce clusters of (C6F6)I–. Frequency-resolved measurements of this cluster revealed a mechanism for electron loss below the threshold for the single-photon direct detachment process. This suggested the presence of a charge-transfer channel centred around hv = 3.3 eV. Time-resolved measurements of (C6F6)I– confirmed the presence of the charge-transfer state and revealed an instantaneous and coherent transfer of the electron onwards into the valence orbital system of the C6F6 molecule. This transfer of charge causes the molecule to vibrate as its geometry changes from planar to buckled. The oscillations observed in the photoelectron spectra are coherent and sinusoidal and have a frequency of 121 ± 2 cm−1. This compares very favourably to the frequency of 122 cm−1 calculated by time-dependent density functional theory for the bending mode of C6F6 along the coordinate between the planar and buckled geometries. I argue that this charge-transfer state exhibits the predicted characteristics of a CBS.
5
Kervarec, Maëva-Charlotte. « Reactivity of Aluminium chlorofluoride (ACF) towards C−F bond activations and C−F bond formations ». Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://edoc.hu-berlin.de/18452/24074.
Texte intégralRésumé :
Der Fokus dieser Dissertation lag in der Untersuchung des Potentials von Aluminium-chlorofluorid (ACF) als Katalysator für die Synthese von fluorierten Verbindungen. Insbesondere die C−F-Aktivierung von verschiedenen polyfluorierten Stoffen wurde untersucht, welches die Effizienz des festen Lewis-Säure-Katalysators für diesen Reaktionstyp zeigte. Das potente Treibhausgas 2-Chlor-1,1,1,2-tetrafluorpropan wurde erfolgreich in das dehydrofluorierte Produkt. Weiterhin wurden Umsetzungen von Pentafluorpropan-Isomeren wie z.B. 1,1,1,3,3-Pentafluorpropan, 1,1,1,2,2-Pentafluorpropan und 1,1,1,2,3-Pentafluorpropan mit ACF als Katalysator untersucht. Es konnte gezeigt werden, dass die Aktivierung der primären CH2F-Gruppe in schnell stattfindet und dabei keine Wasserstoffquelle erfordert. Im Kontrast dazu, wurde für die Aktivierung von CF2-Gruppen eine Wasserstoffquelle wie etwa HSiEt3 benötigt und resultierte in der Bildung eines Produktgemischs. Alternativ wurden Hydrofluorierungsreaktionen von mehreren Substraten durch die Synthese und den Einsatz eines neuen Materials erreicht, welches auf der Immobilisierung von HF auf der Oberfläche von ACF beruht. Dieses HF-ACF wurde unter der Verwendung von vielfältigen Charakterisierungsmethoden umfassend untersucht. Die innere Struktur des Festkörpers, wurden mit MAS-NMR-Spektroskopie, FTIR, Inelastische Neutronenstreuung, XRD und Thermoanalyse analysiert Dadurch konnte gezeigt werden, dass eine geringfügige Reorganisation des bulks zu einer besser geordneten Matrix und die Bildung einer mit der ACF-Oberfläche wechselwirkenden Polyfluorid-Struktur vorliegt. Zur Bestimmung der Oberflächengröße wurde das BET-Modell genutzt und zur Analyse der Porengröße wurde die NLDFT verwendet. Abschließend wurden verschiedene Probeverbindungen an der Oberfläche des HF-ACFs adsorbiert um die Azidität der Oberfläche zu bestimmen und es konnte gezeigt werden, dass eine signifikante Reduktion der Lewis- und Brønsted-Azidität vorliegt.The main focus of this thesis lies in the study of the potential of aluminum chlorofluoride (ACF) as a catalyst for the synthesis of fluorinated compounds. In particular, C−F bond activations of various polyfluorinated compounds were studied, showing the efficiency of this solid Lewis acid catalyst for this type of reaction. The potent greenhouse gas 2-chloro-1,1,1,2-tetrafluoropropane was successfully transformed into the dehydrofluorination product 2-chloro-3,3,3-trifluoropropene under mild conditions. Similarly, transformation of pentafluoropropane isomers, such as 1,1,1,3,3-pentafluoropropane, 1,1,1,2,2- pentafluoropropane and 1,1,1,2,3-pentafluoropropane was also investigated using ACF as a catalyst. It was evidenced that the primary CH2F group present in 1,1,1,2,3-pentafluoropropane was easily activated without the need for a hydrogen source. In contrast, to activate CF2 groups, a hydrogen source such as HSiEt3 was required, generating a variety of products. Alternatively, successful hydrofluorination reactions of several substrates were conducted by synthesizing a new material, based on the loading of hydrogen fluoride (HF) at the surface of ACF. This HF-loaded ACF was deeply studied using a wide range of characterization methods. For the bulk, MAS NMR spectroscopy, Fourier Transform Infrared spectroscopy (FTIR), Inelastic Neutron Scattering (INS), Powder X-Ray Diffraction (P-XRD), and thermoanalysis were performed, revealing a slight reorganization of the bulk towards a better-ordered matrix and the formation of polyfluoride structure interacting with the surface of ACF. The BET model was used for the surface area determination, and the pore size analysis was established using the non local density functional theory (NLDFT). Finally, various probe molecules were adsorbed at the surface of HF-loaded ACF to determine the acidity of the surface, revealing a significantly reduced Lewis and Brønsted acidity.
6
Pleyer, Marcus C. F. [Verfasser]. « Föderative Gleichheit. / Marcus C. F. Pleyer ». Berlin : Duncker & ; Humblot, 2019. http://d-nb.info/1238344577/34.
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7
Roucaute, Yves. « Le P. C. F face à l'état ». Paris 10, 1985. http://www.theses.fr/1985PA100232.
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8
Herbaut, Audrey. « C. F. Ramuz ou l'esthétique du refaire ». Artois, 2007. http://www.theses.fr/2007ARTO0007.
Texte intégralRésumé :
Que ce soit dans ses ouvrages fictifs, critiques ou biographiques, C. F. Ramuz témoigne d’un incessant besoin de réécrire ses œuvres, de les refaire. Qui plus est, le sème du refaire est très présent, voire obsédant, et notre sujet se propose donc d’en explorer les diverses acceptions pour montrer comment la refabrication à l’œuvre dans la création ramuzienne vise à retrouver un cosmos édénique et pérenne, où homme et nature seraient en harmonie, démarche transfiguratrice autant pour l’œuvre que pour l’auteur. Tout d’abord, le paradoxe d’une écriture et d’un écrivain cherchant à atteindre l’élévation par l’humilité, qui prétendent se faire en se défaisant, régresser pour progresser, témoigne du lien intime entre l’éthique et l’esthétique. Ensuite, le sème plastique du refaire et les résonances picturales de l’œuvre sont à lire comme autant de manifestations de la volonté solidificatrice de l’auteur, voire comme un remède à la fugitivité de l’écriture. Puis, l’humanisation de la nature permet à l’auteur de revaloriser la « taille de l’homme » et d’accéder à la grandeur cosmique, dans une relation d’émulation. Enfin, le souffle mythique du cosmos montagnard et la dimension mystique qu’acquiert ainsi l’auteur ont révélé la proximité de la genèse chrétienne et de la génétique ramuzienne. C. F. Ramuz ambitionne donc, à travers le chant de son Rhône , retrouver la « raison d’être » d’ « un pays et d’un homme intimement mêlés ».
9
Richou, Françoise. « La J. O. C. F. Dans l'Ouest ». Nantes, 1986. http://www.theses.fr/1986NANT3012.
Texte intégralRésumé :
De mille-neuf-cent-vingt-sept a mille-neuf-cent-quatre-vingt-cinq, le mouvement de la jeunesse ouvriere chretienne, dans ses deux organisations, masculine (j. O. C. ), feminine (j. O. C. F. ), a change. Dans ses adherents : de mouvement de jeunesse, il est devenu organisation de jeunes militants. Dans ses objectifs : de la " rechristianisation ", il est passe a la construction de " l'eglise en classe ouvriere ". Ayant forme, avec ses homologues, la majeure partie du personnel " politique " des annees cinquante et soixante, il est toujours " ecole de militants ". " ouvrier " au sens strict avant-guerre (la quasi-totalite des adherents et des responsables sont de jeunes salaries), l'est-il encore a partir des annees soixante ou les scolaires penetrent en force l'organisation? telles sont les questions et les analyses que suggere l'etude historique et sociologique, constamment placee dans une perspective nationale, de quelques federations jocistes de l'ouestFrom nineteen-twenty-seven to nineteen-eighty-five, the youth movement " jeunesse ouvriere chretienne ", with its two organizations, male (joc), female (jocf), has changed. In its recruitment : from youth movement to young militants's organization. In its plans : from the conversion of the working class to christianity to the settling of church in the working class. It has formed most of the political staff of the sixties with the other youth movements. It is always school of militants. According to its militants's social status, is it ever a working class organization nowadays where it is so present in schools? the historical and sociological study of some federations "joc f" in west of france, always placed in a national viewpoint, leads to these questions and analysis
10
Zhang, Qi. « Transition-metal-catalyzed C-F bond formation ». Diss., University of Iowa, 2016. https://ir.uiowa.edu/etd/3228.
Texte intégralRésumé :
Fluorine atom plays a very important role in pharmaceuticals, agricultural chemicals, and medical imaging and it has become one of the most popular area in organic chemistry. For example, in modern medicinal chemistry introducing fluorine atom could potentially improve absorption, metabolism and potency of drug candidates. As a result, methods that allow the selective and efficient formation of the carbon-fluorine bond are highly desirable. An evolving approach is the utilization of transition-metals to catalyze the nucleophilic substitution of fluoride ion. This thesis described several novel and efficient methods to generate allylic and benzylic C-F bonds using rhodium/iridium catalyst.
11
Mekideche, Abdeslam. « Effet mémoire de forme et plasticité de transformation dûs à la transition C. F. C. ↔T. F. C. D'alliages Mn Cu riches en Mn ». Lyon 1, 1985. http://www.theses.fr/1985LYO19016.
Texte intégralRésumé :
Les alliages Mn-Cu riches en Mn ( 80-100 %) trempés depuis haute température à 1’état cubique à face centrées présentent vers la température ambiante une transformation sans diffusion c. F. C. ↔ t. F. C. à caractère quasi-martensitique. Ce travail a pour objet l'étude de la plasticité de transformation et de la mémoire de forme liés à cette transition. Un appareil simple permettant la mesure de la déformation de flexion de plaquettes en fonction de la température et de la charge appliquée , a été mis au point et utilisé. Il a été montré que la plasticité de transformation comme l'effet mémoire de forme sont relativement limités en amplitude ( 0,6 % ) et qu 'ils s'accompagnent presque toujours de déformation plastique vraie. Des mesures complémentaires : diffraction X, résistivité, frottement intérieur et observation au microscope optique ont été effectuées et ont contribué à montrer qu'une partie importante de la déformation de l'effet mémoire est à attribuer à la variation des paramètres cristallins de la martensite t. F. C. Lorsqu'il y a dissymétrie entre les variantes.
12
Akana, Jennifer Anne. « Catalytic C-N and C-F bond formation by organometallic group 11 complexes ». Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/39585.
Texte intégralRésumé :
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2007.Vita.
Includes bibliographical references.
This thesis presents a study of the reaction between an (NHC)gold(I) fluoride complex (NHC = N-heterocyclic carbene) and alkynes (Chapter 1). Gold(I) and fluoride add trans across the triple bond of 3-hexyne and 1-phenyl-l-propyne to form (fluorovinyl)gold(I) complexes, with exclusive geminal arrangement between the phenyl group and gold in the latter case. This addition is reversible, and the (fluorovinyl)gold(I) complexes can extrude alkyne to return (NHC)gold(I) fluoride. Treatment of (fluorovinyl)gold(I) complexes with strong acid protonates the vinylic group with strong acid to afford trans-hydrofluorination. The same fluoroalkene product is obtained by treatment of an (1i2-alkyne)gold(I) complex with the mild HF source Et3N.3HF. Cationic (NHC)gold(I) complexes catalyze the trans-hydrofluorination of internal alkynes with Et3N*3HF (Chapter 2). Sterically demanding, electrophilic supporting ligands and the presence of acid buffers improve reaction efficiency. A study of aryl-substituted alkynes suggests that electron-poor aryl groups favor shorter reaction times and higher regioselectivity of fluorination. A heavily fluorinated phenanthroline ligand supporting a cationic copper(I) catalyst allows efficient functionalization of C-H bonds using sulfonyl azides (Chapter 3).
(cont.) Performing the reaction in 1,1,1,3,3,3-hexafluoroisopropanol solvent is crucial. The intramolecular cyclization of sulfonyl azides through nitrene insertion into proximate benzylic or aliphatic C-H bonds is established, and efficient intermolecular arene amidation was achieved. The best yields result from using electron-rich substrates and electron-poor azides. A small kinetic isotope effect measured for the amidation of benzene indicates that C-H bond activation is probably not the rate-determining step. The presence of a 1,2-shift is consistent with an electrophilic mechanism for arene activation. The formation of both aryl- and benzyl-substituted products from mesitylene indicates that different reaction pathways may compete in the electrophilic amidation process.
by Jennifer Anne Akana.
Ph.D.
13
Politano, Olivier. « Simulations mésoscopiques de la déformation plastique des monocristaux C. F. C. Sous contrainte ». Dijon, 1999. http://www.theses.fr/1999DIJOS066.
Texte intégralRésumé :
Ce travail de thèse a pour objectif la présentation de simulations numériques adaptées à l'étude des premières étapes de la déformation plastique dans les systèmes c. F. C. Dans ce travail, nous nous sommes efforcés d'exposer le plus clairement possible les différences conceptuelles et techniques entre notre modèle et d'autres approches à 3D. Pour cela, dans un premier temps nous présentons les modes de discrétisation coin-vis et coin-vis-mixte (CVM) utilisés dans les approches mésoscopiques de la dynamique des dislocations. Nous soulignons plus particulièrement, les différences qui résultent des calculs de l'énergie propre des lignes de dislocation et des champs de contraintes entre ces deux descriptions. Nous concluons en exposant les critères qui nous ont conduits à adopter une description CVM. Dans un second temps, nous détaillons la dynamique des dislocations et la manière dont nous avons procédé pour calculer les forces agissant sur les segments de dislocations. Dans une seconde partie, nous explicitons les calculs effectués pour valider notre modèle par l'étude d'une source de Frank Read (FR). A cette occasion, nous montrons que notre modèle reproduit la contrainte critique d'activation d'une source de FR, en utilisant une valeur de paramètre de tension de ligne adaptée à notre mode de discrétisation. Dans une nouvelle étape, nous détaillons les études en glissement simple qui nous ont permis de reproduire, la formation de murs dipolaires. Ensuite, nous exposons, les simulations développées pour caractériser la force des jonctions entre dislocations et enfin, nous montrons que la valeur numérique obtenue pour l'angle critique de rupture d'une jonction est en bon accord avec d'autres approches et qu'elle permet de simuler un essai de traction uniaxiale en reproduisant le mécanisme de durcissement par la forêt.
14
Weiss, Paula. « Ab initio and Direct Quasiclassical Trajectory Study of the F + CH₄ → HF + CH₃ and F + C₂H₆ → HF + C₂H₅ Reactions ». Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/35340.
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The reparametization of semiempirical Hamiltonians is an emerging method used
in direct dynamics studies. The use of semiempirical Hamiltonians in direct dynamics
studies diminishes the computational cost of trajectory calculations and negates the need
for an analytical potential energy surface when performing reaction dynamics studies.
The reparametization of semiempirical Hamiltonians increases the agreement with
experiment and high level ab initio theory. We have chosen to create one set of new
parameters that apply to two related reactions, F + CH4 â HF + CH3 and F + C2H6 â HF
+ C2H5. We have performed an electronic structure study for these reactions. The ab
initio data obtained from the electronic structure study is then used as the reference for a
reparametization of the PM3 Hamiltonian. The reparametization has improved the ab
initio and PM3 reaction energy and potential energy surface scan agreement. This new
set of parameters for PM3 (SRP-PM3) is used to perform a direct quasiclassical trajectory
study of the reactions. The vibrational and rotational HF distributions calculated using
SRP-PM3 are compared with experiments. We have observed an improvement in the
agreement with experimental vibrational distributions but have seen no change in the
rotational distributions.Master of Science
15
Müller, Valentin [Verfasser]. « C–H and C–F Activation by Manganese, Nickel and Ruthenium Catalysis / Valentin Müller ». Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2021. http://d-nb.info/1232492787/34.
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Decultot, Ludovic. « Towards the total synthesis of amphidinolides C and F ». Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/7607/.
Texte intégralRésumé :
The amphidinolides are marine macrolides extracted from dinoflagellates of the genus Amphidinium. To date, 37 amphidinolides have been isolated and identified, most of them possessing cytotoxicity against human cancer cell lines. Among these, amphidinolides C, F, C2 and C3 represent synthetic targets of interest owing to their scarcity, structural complexity and promising biological activities. This thesis describes the work realised towards the total synthesis of amphidinolides C and F, with a focus on the different strategies investigated and the key fragments synthesised. In the first approach, the C18−C29 fragment of amphidinolide F was prepared using an intramolecular etherification of an epoxide under acidic catalysis to produce the 2,5-trans-disubstituted tetrahydrofuran ring featured in the natural product. Unfortunately, dithiane alkylation with the C1−C17 iodide counterpart generated the desired coupling product in low yield. A second approach proposing to build the C17−C18 bond by a silicon-tethered RCM proved unsuccessful, because the requisite diene could not be obtained. It was then envisioned to form the C18−C19 bond by displacement of a triflate with an alkyne and install the ketone at C18 by a protoborylation/oxidation sequence. To this end, the C19−C29 triflate precursor was synthesised. Displeasingly, the C1−C18 alkyne counterpart (work by Dr Filippo Romiti) could not be prepared and coupling of the two fragments was not attempted. In the latest approach, the C10−C29 fragment of amphidinolide F was obtained employing a boron-mediated aldol condensation and a dithiane alkylation to form the C13−C14 and C18−C19 bonds. Several endgame strategies were examined including the successful Yamaguchi esterification of the C13-epi C10−C29 fragment and the C1−C9 acid. A challenging Stille crosscoupling was then effected to close the macrocycle but only yielded the desired macrolactone in trace amounts after global desilylation.
17
Pyrkotis, Constantina. « Towards the Synthesis of Amphidinolides C, F and U ». Thesis, Imperial College London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486568.
Texte intégralRésumé :
The amphidinolides are a family of structurally-related cytotoxic natural products which have shown powerful antitumour activity against murine lymphoma (LI210), human epidermoid carcinoma (KB) and human colon tumor cells (HCTI16). They occur naturally in only minute 'amounts, in specific strains of the microscopic marine dinoflagellate amphidinium sp. Total synthesis therefore becomes an important potential source of theSe natural products. Chapter One presents the amphidinolide family and specifically the isolation, structural features, biosynthesis and elucidation of the �·absolute configuration of amphidinolides C, F and U, then goes on to review the syntheses of specific fragments of amphidinolides C and F. Finally, we discuss our retrosynthetic approach towards amphidinolide C. Chapter Two begins with our approach to the synthesis of the (C18-C25) THF-fragment, including a successful 9- step route which utilizes an asymmetric dihydroxylationiodoetherification strategy. We continue with the installation of the simple side chain of amphidinolide F via a Wittig reaction and the synthesis of the (CI8-C29) dithiane in three steps. We then go on to present our approaches towards the synthesis of the (C18-C34) fragment of amphidinolides C and U. Firstly, we investigated a Stille-NHK coupling approach towards the installation of the side chain of amphidinolides C and U which was unsuccessful. Secondly, we examined a Stille coupling approach for the synthesis of the (C27-C34) fragment by using Carreira's enantioselective formation of propargylic alcohols and Negishi carboalumination.Although we installed the C29 stereocentre with excellent enantioselectivity, application of the carboalumination reaction failed. Thirdly, we examined a Stille coupling for the synthesis ofthe (C27-C34) fragment by using cuprate chemistry and asymmetric CBS-reduction. This approach showed success in the synthesis of the complex side chain, but epimerization at the C29 stereocentre was observed at the .final step. The fourth approach attempted was a three step synthetic transformation of the simple side chain of amphidinolides c- and U which involved a diene-allylic hydroxylation, oxidation and NHK coupling. This route was fmally chosen for the installation of the side chain. We then discuss our approach towards the (ClO-C17) fragment of amphidinolides C and F which involves a dithiane alkylation approach. We show the syntheses of the (C15-C17)-dithiane in 5 steps starting from the (S)-Roche ester and the (Cll-C14)-epoxide in 7 steps starting from D-malic acid or from the but-2yne- I,4-diol and we then go on to talk about the dithiane coupling. Chapter Three reviews the findings presented in Chapter Two and describes the route towards the total synthesis of the three natural products. Chapter Four gives full experimental details, spectroscopic and physical data for all new compounds prepared. /
18
Hazari, Amaruka. « Palladium catalysed alylic-C-F bond formation and activation ». Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526523.
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Hajjaji, Mohamed el. « Caractérisation et simulation des joints de phases C. C. -C. F. C. : applications à des alliages Fe-Cr-Ni de différentes puretés ». Lyon 1, 1986. http://www.theses.fr/1986LYO10015.
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Presentation des resultats de simulation des joints de phase entre structures cubiques centrees (c. C), cubiques et cubiques a faces centrees (c. F. C. ). Calcul des indices de coincidence entre les phases cubiques centrees et cubiques a faces centrees liees par une famille de relations d'orientation cristallographique. Etude experimentale des joints de phases entre structures c. C-c. F. C sur des alliages fe-ni-cr. La presence d'aluminium dans ces alliages aboutit a l'apparition de certains precipites. La diffusion des impuretes c ou s dans des alliages de tres haute purete provoque un arrangement localise des atomes autour des joints de phases, ce nouvel arrangement modifiant les relations d'orientation cristalline
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Gooseman, Natalie. « The influence of the C-N⁺------F-C charge dipole interaction in fluoro organic chemistry / ». St Andrews, 2008. http://hdl.handle.net/10023/695.
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Dryzhakov, Marian. « Nitro-assisted Brønsted acid catalysis : activation of C(sp3)–O and C(sp3)–F bonds ». Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF012/document.
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Les alcools sont des partenaires électrophiles attractifs pour des réactions de substitution nucléophile puisque l'eau est le seul sous-produit de la réaction en présence de nucléophiles protiques. Malgré le fait que la réaction soit fortement intéressante, la portée des transformations catalytique reste limitée à une combinaison spécifique alcool/nucléophile, ce qui rend l’emploi d’un ensemble général de conditions catalytiques fortement élusif. Cette thèse décrit le développement d'un système général de catalyse doux pour l'activation d'une large gamme d’alcools π-activés ainsi que d’alcools aliphatiques abordant ainsi les limitations clés dans le domaine. B(C6F6)3•H2O, un acide de Brønsted fort quand il est combiné avec le nitrométhane, a été découvert comme étant un système catalytique idéal pour la substitution chimiosélective d'alcools en présence de fonctionnalités et de groupements protecteurs sensibles aux conditions acides sans le compromis typique entre vitesse de réaction, réactivité substrat/nucléophile et quantité de catalyseur. Plus particulièrement, un effet co-catalytique de composés nitro est décrit pour la réaction d’azidation des alcools aliphatiques tertiaires en employant B(C6F6)3•H2O, permettant, pour la première fois, un turnover catalytique. Sur la base des investigations cinétiques, électroniques et spectroscopiques qui ont été menées, des agrégats de composés nitro et d’acides liés par des intéractions hydrogènes sont proposé comme étant l’espèce catalytiques responsables de la cinétique de la catalyse observée. L'utilité des nouvelles conditions catalytiques a été étendue au-delà de l'activation d'alcool et appliquée au clivage des liaisons fortes C-F dans les réactions de Friedel-Crafts défluorinatives de fluorures aliphatiques tertiairesAlcohols are attractive electrophilic partners for nucleophilic substitution reactions as water is the only by-product in a reaction with protic nucleophiles. Despite being a highly desirable reaction, the scope of useful catalytic transformations remains limited to specific alcohol-nucleophile pairs and a general set of catalytic conditions remains elusive. This thesis describes the development of a general and mild catalyst system for the activation of a broad range of π-activated and aliphatic alcohols to address key limitations in the field. B(C6F6)3•H2O, a strong Brønsted acid, when combined with nitromethane has been found as a widely useful catalyst system for chemoselective alcohol substitution in the presence of acid sensitive functionalities and protecting groups without the typical compromises in reaction rates, substrate/nucleophile scope and catalyst loading. In particular, a co-catalytic effect of nitro compounds is described for the B(C6F6)3•H2O catalyzed azidation of tertiary aliphatic alcohols, enabling catalyst turnover for the first time. On the basis of kinetic, electronic, and spectroscopic investigations, higher order hydrogen-bonded aggregates of nitro compounds and acids are proposed as kinetically competent Brønsted acid catalysts at the origin of the enhanced reactivity. The utility of the new catalytic conditions has been extended beyond alcohol activation and applied to the cleavage of strong C–F bonds in defluorinative Friedel-Crafts reactions of tertiary aliphatic fluorides
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Gooseman, Natalie Elizabeth Jane. « The influence of the C-N⁺ ----- F-C charge dipole interaction in fluoro organic chemistry ». Thesis, University of St Andrews, 2008. http://hdl.handle.net/10023/695.
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Chapter 1 introduces the discovery of elemental fluorine by H. Moissan and some uses of inorganic fluoride. Organo fluoro compounds and their place in pharmaceuticals and agrochemicals are also introduced. The general properties of fluorine and the C-F bond are discussed as well as conformational influences such as the fluorine gauche effect. Chapter 2 describes the C-N⁺------F-C charge dipole interactions within protonated amines and explains the influence of a β fluorine on the conformation on various crystalline structures. A number of systems are synthesised which contain this charge dipole interaction, such as four, five and eight membered aza heterocycles. It was demonstrated that these provided a N⁺-C-C-F gauche torsion angle. This electrostatic effect was also observed in the non-protonated N-ethylpyridinium cations possessing a fluorine β to the charged nitrogen. This clearly showed that hydrogen bonding is not playing a part in the observed N⁺-C-C-F gauche interactions and that it is a purely electrostatic effect. Chapter 3 discusses the effort to explore the C-O⁺-------F-C charge dipole interaction and the synthetic approaches that were taken towards candidate substances. However in the event a Grignard reaction on a fluoro cyclohexanone was found to provide an unexpected product where rearrangement followed by fluorine elimination had occurred. Chapter 4 details the experimental procedures for the compounds synthesised in this thesis and an Appendix outlines the detail of 24 crystal structures that were solved during this research.
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Althaus, Martin. « Asymmetric C - F bond formation catalyzed by ruthenium PNNP complexes / ». Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17673.
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Launay, Guillaume. « New approaches for C-F bond formation in organic chemistry ». Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/922.
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The importance of fluorinated organic molecules has grown over the last 50 years, particularly in the pharmaceutical and agrochemical industries. Therefore the development of new methods for fluorination is a very attractive research area. In Chapter 1, the properties and impact of the fluorine atom on organic molecules are overviewed. Existing electrophilic and nucleophilic fluorination methods are reviewed, and new developments in asymmetric fluorination are discussed. The emergence of the Prins fluorination reaction as a side product in BF₃.OEt₂ catalysed processes has been investigated as a synthesis method in Chapter 2. Indeed, it is possible to form 4-fluorotetrahydropyrans with some diastereoselectivity from an allylic alcohol and an aldehyde with a stoichiometric amount of BF₃.OEt₂. During this study, formation of 4-fluoropiperidines from N-tosyl-4-butenylamine was achieved. Optimisation of reaction conditions was investigated such as the solvent, the reaction temperature and the influence of substituents on the alcohol and the aldehyde reagents. A ring-opening reaction of 4-fluoro-2-phenyltetrahydropyran was successfully performed. Both oxa-Prins and aza-Prins fluorination reactions were investigated under microwave conditions, allowing reduced reaction times, a process that had a minimum impact on the diastereoselectivity. Attempt to form γ-hydroxy-α-vinylfluorides by the reduction-fluorination of propargylic alcohols with aluminium hydride, or by Horner-Emmons reaction with diethyl (fluoromethyl)phosphonate are reported in Chapter 3. Unfortunately these approaches were unsuccessful in the preparation of γ-hydroxy-α-vinylfluorides. Attempts to fluorinate epoxides by α-lithiation and then treatment with electrophilic fluorination reagents gave encouraging results, but the products could not be purified and characterised due to an apparent instability.
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Pigeon, Xavier. « Synthèse de ß-aminofluoroalcènes par l'activation de liens C-F ». Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27728/27728.pdf.
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Nagaoka, Gabriel Nicolaz. « Introdução às Anomalias Conformes e os Teoremas C & ; F ». Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-04052018-140729/.
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As ideias fundamentais sobre entropia de emaranhamento e fluxos de renormalização são expostas, assim como uma introdução a CFTs e sua ligacão com a estrutura do espaco de parâmetros. A anomalia de traço é calculada em uma abordagem semi-clássica usando o método de heat kernel\" e regularização por função zeta . Mostramos que os coeficientes de Seeley-DeWitt são responsáveis pela quebra de simetria conforme em um espaço-tempo curvo de dimensão par, com isso alcançamos uma definição geométrica para as cargas centrais. A inexistência de anomalias no caso de dimensões ímpares também e mostrado. O C-theorem\", que prova a monotonicidade das cargas centrais sob o fluxo de renormalização, é demonstrado como feito por Zamolodchikov por meio de uma abordagem euclideana assumindo unitariedade, positividade por reflexão e condições de renormalizabilidade. A análise feita por Cardy também e demonstrada, nela considera-se os mesmos ingredientes. Por fim, a prova tecida por Casini & Huerta é demonstrada com detalhes, essa prova utiliza das propriedades de strong subadditivity da entropia de emaranhamento, unitariedade e invariância sob o grupo de Poincaré. Com isso, uma conexão com informação quântica é feita naturalmente. No último capítulo generalizamos o conceito de carga central para dimensões ímpares as definindo como o termo universal na entropia de emarahamento de uma esfera. As considerações geométricas feitas para provar o C-theorem\" são estendidas para um espaço-tempo de Minkowski com três dimensões. Como consequência temos a prova do F-theorem\" que é o analogo em três dimensões do C-theorem\".The fundamental ideas of entanglement entropy and RG flows are laid out, as well as the basics of CFTs and its connection to the framework of RG flows. The trace anomaly is calculated in a semi-classical fashion by using the heat kernel method and zeta-function regularization. It is shown that the Seeley-DeWitt coefficients are responsible for the breaking of conformal symmetry in a curved even-dimensional background, which also achieves a geometrical definition of a central charge. The absence of anomalies in odd space-time dimensions is also contemplated. The C-theorem, which proves the monotonicity of the two dimensional central charge under RG flows, is demonstrated as first done by Zamolodchikov in an euclidean approach assuming unitarity, reflection positivity, and renormalizability conditions. Cardy\'s analysis is also demonstrated by considering the same conditions as Zamolodchikovs . And at last the proof via entanglement entropy by Casini & Huerta which relies on the strong subadditivity property of EE, unitarity and Poincaré invariance is explained in detail, providing a quantum information approach to the problem. In the last chapter a generalization of central charges to odd dimensional space-times is given through the universal term of the EE of a sphere. We provide the extension of the geometrical setup considered in the proof of the C-theorem to a three dimensional Minkowski space-time, which ultimately yields the F-theorem, constituting the three dimensional analog of the C-theorem.
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Hough, Sarita Elizabeth. « Regioselective, Nucleophilic Activation of C-F Bonds in o-Fluoroanilines ». Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/90657.
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Reactions of fluorinated anilines with stoichiometric Ti(NMe2)4 in mesitylene (typically for 23 h at 120 °C) afforded moderate to high yields of the corresponding N,N-dimethyl-o-phenylenediamine derivatives resulting from defluoroamination of a fluorine atom ortho to the NH2 of the starting aniline. Reactivity increased with additional ring fluorination in general accordance with established regiochemical (activating and deactivating) trends. Based on results, we propose a metal-mediated, SNAr-based mechanism. We report the scope and limitations of this reaction and discuss trends in reactivity according to a putative mechanistic scheme.Master of Science
This thesis describes reactions of fluorinated anilines with titanium amides to make fluorinated 1,2-phenylenediamines. The reaction gives high to moderate yields, and is highly selective for ortho substitution. The scope of the reaction, trends in reactivity among substrates, product characterization, and reaction mechanism are discussed. This reaction is of interest because fluorinated aniline derivatives are a privileged structural motif in pharmaceuticals and agricultural chemicals. The first chapter presents an overview of C-F bond activation and key background information. Chapter 2 is a description of the experiments and an in-depth analysis of their results. Chapter 3 presents detailed characterization data for substances generated in this research. Chapter 4 comprises some concluding remarks and plans for possible future extensions of the research.
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Pigeon, Xavier. « Synthèse de β-aminofluoroalcènes par l'activation de liens C-F ». Master's thesis, Université Laval, 2010. http://hdl.handle.net/20.500.11794/22213.
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L'introduction d'un atome de fluor dans une molécule bioactive peut bien souvent modifier son activité biologique en modifiant sa lipophilic, sa solubilité, sa stabilité métabolique, sa conformation ou encore sa réactivité chimique. C'est pourquoi la synthèse de produits organofluorés suscite un intérêt marqué dans le secteur de l'agrochimie et de la chimie pharmaceutique. D'ailleurs, les moyens d'accès à ces produits sont en constante augmentation. Non seulement la formation mais également l'activation de liaisons C-F sont des sujets de recherche très prometteurs pour la conception de produits organiques fluorés. Les métaux de transition tels que le nickel, le palladium et le rhodium jouent un rôle important dans l'activation de liens C-F. Dans ce mémoire, il sera question de la synthèse des β-aminofluoroalcènes qui sont une classe de molécules organofluorées suscitant un intérêt particulier en chimie médicinale, car ils peuvent être utilisés comme isostères de la liaison peptidique. Cependant, il n'existe pas de voie directe afin d'accéder à cette classe de composés. Nous nous sommes donc intéressés à rechercher des voies de synthèses permettant l'obtention de p-aminofluoroalcènes. Dans ce mémoire, deux stratégies seront abordées pour la synthèse des p-aminofluoroalcènes. D'une part, une méthode basée sur la réaction d'amination allylique de dérivés de 3,3-difluoropropènes sera présentée. Celle-ci est catalysée par le palladium via l'activation d'un lien C-F. D'autre part, une stratégie basée sur une réaction de type SN2' utilisant les amidures de lithium sur des systèmes allyliques de dérivés de 3,3-difluoropropène constituera la dernière partie de ce mémoire.
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Champagne, Pier Alexandre. « Activation de liens C-F à l'aide de liaisons hydrogène ». Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/26272.
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Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2015-2016L’activation de liens C–F a été un sujet de recherche prolifique des dix dernières années, considérant l’utilité de telles études pour mieux comprendre et utiliser le comportement des composés fluorés. Toutes les méthodes qui existent pour réaliser la substitution nucléophile de fluorures aliphatiques tirent profit d’interactions faibles en conditions acides ou basiques, ou de métaux de transition. Cependant, une interaction comme la liaison hydrogène avec un lien C–F, certainement faible en énergie, n’a toujours pas été utilisée pour réaliser l’activation en conditions neutres. Après une introduction sur l’activation C–F et leur capacité d’accepteur de liaisons hydrogène, divers systèmes utilisant cette faible interaction pour la substitution nucléophile de fluorures aliphatiques, qui ont été développés dans cette thèse, seront présentés. Plusieurs types de donneurs de liaisons hydrogène (DLH) ont été utilisés au courant de la thèse, notamment l’eau, les alcools polyfluorés, ainsi qu’une large gamme d’alcools, diols, triols et autres groupements donneurs. En présence de nucléophiles variés, il a été démontré que les liaisons hydrogène sont suffisamment puissantes pour permettre la transformation de composés organofluorés par l’activation et la substitution de leur lien C–F. L’analyse des mécanismes réactionnels a aussi démontré qu’en plus de nécessiter des activateurs pour pouvoir le substituer, le lien C–F conserve un certain caractère spécial dans nos conditions avec les DLHs. Pour nos systèmes de substitution nucléophile, un mécanisme SN2 semble correct, tandis que dans les réactions de Friedel-Crafts, des paires d’ions fortement retenues par les liaisons hydrogène semblent expliquer la réactivité observée mieux qu’un mécanisme ionisant SN1 classique ne pourrait le faire.
C–F activation has been a subject of intensive research over the last decade, considering the usefulness of such studies to understand, predict and profit from the unusual behaviour of fluorinated organic compounds. All methods that are known to enable the nucleophilic substitution of aliphatic fluorines use weak interactions in acidic or basic conditions, or require transition metals. However, hydrogen bonds with fluorine, energetically-weak interactions, have not yet been harnessed to activate C–F bonds in neutral conditions. After an introduction on C–F activation and on the possibility of these bonds to accept hydrogen bonds, various systems that exploit this weak interaction for the nucleophilic substitution of aliphatic fluorines and that were developed during the thesis, will be presented. Multiple types of hydrogen-bond donors (HBD) were used to affect this transformation, notably water, polyfluorinated alcohols and a wide variety of alcohols, diols, triols, and other donating groups. In the presence of varied nucleophiles, it will be shown that hydrogen bonds are strong enough to permit the transformation of organofluorine compounds through activation and substitution of their C–F bond. Thorough analysis of the reaction mechanisms demonstrated that, in addition to needing activating agents to be able to substitute it, the C–F bond keeps its unusual behaviour in our conditions with HBDs. In our systems of nucleophilic substitution, a SN2 mechanism seems to operate, while for the Friedel-Crafts reactions, ion pairs strongly kept together by hydrogen bonds are a better explanation for the observed reactivity than the traditional SN1 mechanism involving free carbocations.
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Hozman, Denny. « Preludia F. Chopina, A. N. Skrjabina a C . Debussyho - srovnání ». Master's thesis, Akademie múzických umění v Praze.Hudební a taneční fakulta. Knihovna, 2015. http://www.nusl.cz/ntk/nusl-202920.
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The subject of this thesis is to present the cycles of the preludes composed by F. Chopin, A. N. Scriabin and C. Debussy and to compare them with each other. 3 sorts of criteria will be chosen for that: 1) non-musical criteria, 2) music theory criteria and 3) will be researched through the analysis of chosen music pieces from the cycles. Their common features and differences will be summarized at the end of the each chapter.
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Giffin, Kaitlyn Anne. « Selective C-F and Ni-C Bond Activation of Fluoronickelacycles as a Function of Ancillary Ligands ». Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36619.
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The development of new unconventional routes to small functionalized fluorocarbons (FCs) continues to be an attractive target due to the high utility of FCs in a broad range of applications, including their use as refrigerants, solvents, and surfactants. With the phasing out of hydrofluoroalkanes as refrigerants, there is a growing interest in the synthesis of new hydrofluoroolefins (HFOs), which are known to have significantly reduced global warming potential relative to hydrofluoroalkanes. Currently, energy-intensive conditions and toxic starting materials are typically necessary for their syntheses, making these processes environmentally problematic. The approach we have proposed for alternative ‘greener’ methods for functionalized FC production targets a transition metal-catalyzed synthesis involving the formation of metallacyclic intermediates through the oxidative cycloaddition of simple fluorinated alkenes, e.g., tetrafluoroethylene (TFE) and trifluoroethylene (TrFE), at low-valent nickel centres.
There is precedent for the generation of short fluoroalkyl chain (C4-C6) compounds through homogeneous catalysis. For example, Baker et al. showed that you could catalytically hydrodimerize two molecules of tetrafluoroethylene (TFE) or one molecule of TFE with one molecule of ethylene using low valent Ni catalysts and π-acidic monodentate ancillary ligands, affording octafluorobutane and 1,1,2,2-tetrafluorobutane respectively.
The objective of this Thesis is to further the state-of-the-art in fluoroorganometallic chemistry by gaining a deeper understanding of transition metal fluoroalkyl complexes as a function of metal-fluoroalkyl and carbon-fluorine bond reactivity. The over-arching goal is to harness said reactivity for the synthesis of new value-added fluorocarbons.
Due to the robust nature of carbon-fluorine and metal-fluoroalkyl bonds in transition metal fluoroalkyl complexes, intensive conditions are often necessary to achieve any reactivity. Recently, bifunctional ligands have proven to be useful at effecting challenging transformations through unconventional ligand-assisted substrate activation pathways. Chapters 2 and 3 herein explore the use of a bidentate phosphinothiol ligand in the context of perfluoronickelacyclopentane reactivity. Synthetic approaches for the formation of phosphinothioether- and phosphinothiolate-supported perfluorometallacycles are outlined along with ensuing reactivity studies, including examples of Cα-F, Cβ-F, and Ni-Cα bond activation. Furthermore, a metal-mediated synthesis of functionalized FC, (E)-1,2,3,3,4,4-hexafluoro-1-butene, is provided. Chapter 4 sheds light on the comparatively underdeveloped chemistry of fluorinated nickelacycles generated from TrFE. A systematic study of monodentate phophine and phosphite ligand effects on metallacyclopentane regio-/stereochemistry is presented. The behaviour of the generated hydrofluoronickelacyclopentanes in the presence of acidic additives allows for a direct analogy to be made regarding the effects of the extent of metallacycle fluorination on C-F and Ni-C activation. In search of new approaches to novel functionalized FC synthesis, Chapter 5 will re-visit the use of bifunctional ligands, investigating the formation and reactivity of new perfluoronickelacycles featuring [P,NH] and [P,Nˉ] bidentate ligands. Finally, Chapter 6 summarizes the findings of this Thesis and discusses some of the future opportunities that will build on this work.
The increased understanding of the stoichiometric systems presented herein will be directly important to the development of nickel-catalyzed routes to HFOs. As the demand for new “greener” refrigerants and propellants increases, the synthesis of small-molecule functionalized FCs using transition metal catalysis and waste fluorinated feedstocks can offer a mild, atom economical approach to new, unique candidates that will be appealing to industrial partners.
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Meier, Thomas Kurt. « Molecular architecture of a biological turbine : the subunit C oligomer the Ilyobacter tartaricus F₁F₀ATP synthase / ». Zürich : [s.n.], 2002. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=14800.
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Freitag-Sweeley, Sandra. « The F/C family of saxophones its history, future and literature / ». Cincinnati, Ohio : University of Cincinnati, 2005. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1121711234.
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BOITIER, GUILLAUME. « Comportement en fluage et microstructure de composites c#f-sic 2,5d ». Caen, 1997. http://www.theses.fr/1997CAEN2080.
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Le comportement en fluage d'un composite c#f-sic 2,5d a ete etudie, sous argon, dans le domaine de temperatures 1273-1673k, pour des contraintes comprises entre 110 et 220 mpa. A cet effet, un dispositif de traction a haute temperature a ete developpe et optimise sur la base d'une etude critique des essais mecaniques a chaud, de facon a obtenir des resultats macroscopiques aussi fiables que possible. Une approche classique a demontre la bonne resistance au fluage du composite c#f-sic 2,5d et mis en lumiere les limites du formalisme de dorn applique au cas particulier des composites a matrices ceramiques. Une seconde approche par la mecanique de l'endommagement a mis en evidence un caractere endommageable plus marque a 1473k et un caractere viscoplastique plus prononce a 1673k. Une investigation microstructurale multi-echelle (par meb, met, mehr et analyse automatique d'images) des materiaux testes a permis, d'une part, d'identifier cinq modes de fissuration et deux modes de glissement interfacial qui, combines, vont conduire a la deformation macroscopique de fluage suivant un mecanisme dependant du temps assimilable a de la propagation lente de fissures. D'autre part, nous avons conclu a la faible contribution de la fibre et de la matrice a la deformation macroscopique de fluage. Cependant, une nanotexturation de la fibre de carbone a ete mise en evidence, conduisant a ce que nous avons appele nanofluage. Le role preponderant de l'interphase de pyrocarbone est clairement etabli. Deux mecanismes distincts de glissement interfacial ont ete identifies : frottement sec entre deux solides rugueux a 1473k et glissement visqueux a 1673k. Des essais de fluage interrompus ont donne acces a la sequence des mecanismes elementaires. Parallelement, une premiere approche de quantification de la fissuration a ete realisee par analyse automatique d'images. Le concept de fluage-endommagement, retenu dans le cas du composite c#f-sic 2,5d, se trouve ainsi illustre.
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Schirrmacher, Esther. « 18 F- und 11 C-Markierung des beta2-adrenergen Agonisten Fenoterol ». [S.l. : s.n.], 2002. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10236413.
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Tarantino, Giulia. « Catalytic methodologies for C(sp3)-F bond formation with heterogeneous catalysts ». Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/111540/.
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Fluorinated compounds are extremely desirable in several fields of the chemical industry, such as pharmaceuticals, materials and agrochemicals. Consequently, the development of novel methods of fluorination represents a major challenge in contemporary chemistry. Although several breakthroughs have been achieved in this area in recent years, the development of an active, stable, reusable and truly heterogeneous catalyst, able to perform selective C(sp3)-F formation, has not yet been achieved. Accordingly, this thesis explores the applicability of heterogeneous catalysts, to perform novel and selective C(sp3)-F bond formations. Different strategies to achieve C(sp3)-F bond synthesis were explored, including: i) fluorination of preactivated substrates (e.g. carboxylic acids), and ii) direct C(sp3)-H fluorination. Firstly, the applicability of heterogeneous materials, such as AgxO/TiO2 and pure TiO2, were investigated for decarboxylative fluorination reactions (R-COOH → R-F), with (photofluorination) and without the employment of light sources. Following an investigation of the catalytic performances of AgxO/TiO2 and pure TiO2 for fluorination of pre-activated substrates, an alternative route, whereby the applicability of heterogeneous materials for direct C(sp3)-H fluorination, was explored. Although more elegant and desirable, direct C(sp3)-H fluorination represents an immense challenge, mainly due to the scarce substrate reactivity, which typically results in a requirement of harsher reaction conditions. Due to the challenges associated with activation of C(sp3)-H bonds, two different systems to achieve direct C(sp3)-H fluorination were investigated. Firstly, the viability of benzylic fluorinations was explored, as these substrates represent excellent model substrates with slightly activated C-H bonds. Secondly, substrates possessing less active C(sp3)-H bonds, such as cyclooctane, were investigated for direct alkane fluorination.
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Divo, Jean. « L'Aubier, la J. O. C. Et la J. O. C. F. Dans le diocèse de Besançon, 1927-1978 ». Strasbourg, 2009. https://publication-theses.unistra.fr/restreint/theses_doctorat/2009/DIVO_Jean_2009_1.pdf.
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La Jeunesse ouvrière chrétienne (J. O. C. ) est fondée dans le diocèse de Besançon en 1927. A l'époque, les enfants des milieux populaires entrent à l'usine ou à l'atelier à la fin de la scolarité obligatoire, 13 ans. La situation de ces jeunes salariés, leur éloignement progressif de l'Eglise préoccupent certains prêtres dont G. Béjot, vicaire à Belfort. Les actions jocistes visent à améliorer les conditions de travail et de vie de ces jeunes. Pendant la guerre, malgré l'interdiction de l'Occupant, la J. O. C. Se maintient, résistant à la tentative de Vichy de créer une Jeunesse unique, à la nazification des esprits en France ou en Allemagne au temps du S. T. O. Par la suite, la J. OC. Soutient apprentis et jeunes travailleurs : proche des syndicats, elle glisse, en fin de période, vers un soutien aux partis de gauche. La méthode du voir, juger, agir conduit à l'action, car, au cours du cercle d'études où l'on dépouille les enquêtes, l'observation de la réalité du quotidien confronté à l'Evangile aiguise le regard. Elle mène à un approfondissement spirituel et à l'engagement syndical, associatif ou politique. C'est à Besançon qu'est inauguré le passage de la révision d'influence à la révision de vie. .A group of he YCW started in the diocese of Besançon in 1927. At that time children from a working class culture started working at thirteen. The situation of those young workers and their growing lack of contact with the Church were a subject of concern for some priests, amon whom G. Béjot, curate at Belfort. . .
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Giroux, Bernard. « La Jeunesse étudiante chrétienne (J. E. C. Et J. E. C. F. ) de 1945 aux années soixante-dix ». Paris, Institut d'études politiques, 2009. http://www.theses.fr/2009IEPP0034.
Texte intégralRésumé :
Cette thèse de doctorat fournit le premier récit de l’Histoire de la Jeunesse Etudiante Chrétienne (J. E. C. ) - masculine et féminine - entre la Libération et les années soixante-dix. Ce mouvement d’Action catholique spécialisé, officiellement reconnu et soutenu par la hiérarchie catholique, mobilise des élèves et des étudiants catholiques et les charge de l’apostolat auprès des autres jeunes Français scolarisés. Son étude est appréhendée comme un observatoire des rapports entretenus par l’Eglise catholique de France avec la modernité, que l’on caractérise comme un processus marqué par la sécularisation de l’Etat, l’avènement du rationalisme et de l’autonomie de l’individu, aux dépens de la tradition, notamment religieuse. A l’issue de l’étude, la J. E. C. Apparaît comme un espace de synthèse entre la modernité et la tradition. Au fil de la réflexion de nombreux thèmes sont abordés, qui intéressent l’Histoire de l’Eglise et de la société française du second XXe siècle : l’auteur montre la contribution de la J. E. C. à la transformation de l’Ecole, de l’Eglise catholique de France, de la vie politique et de la réflexion intellectuelle. Il décrit l’engagement du mouvement dans la lutte contre la guerre d’Algérie, son rôle dans la mutation du regard porté sur le genre féminin, et éclaire l’attitude des catholiques durant les événements de Mai 1968. La thèse est bâtie sur l’exploitation d’un important corpus d’archives jusqu’alors inexploité. Elle fournit en annexe des instruments de travail pour le chercheur futur : la liste des équipes dirigeantes, une prosopographie des responsables nationaux, et le traitement d’une enquête auprès des militantsThis document provides the first account of the History of the Jeunesse Etudiante Chrétienne (J. E. C. ) between 1945 and the seventies. That association is officially acknowledged and supported by the catholic hierarchy. It gathers catholic pupils and students who evangelize other pupils. While studing it, anyone tries to understand the link the french catholic Church keeps up with modernity, which is distinguished as a process marked by the State secularization, the advent of rationalism and the individual’s autonomy, at the expense of tradition, in particular religious. The study finally points out that the J. E. C. Seems to be an area of synthetis between modernity ad tradition. The author emphasizes the contribution from the J. E. C. To the change in the school system, in the catholic Church of France, in policies and in the intellectual thought. The author sets out the commitment of the movement to the fighting against the Algerian war and its attitude in May 1968. The thesis is supported with the analysis of various records which had never been analysed before. Besides the account and analysis of the events, the thesis provides additional tools to the future researcher : the list of ruling staff, a presentation of the officials and the outcome of a survey among former militants
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Tolley, Rebecca. « Frida Kahlo, Jennifer Lopez, Judith F. Baca ». Digital Commons @ East Tennessee State University, 2010. https://www.amzn.com/0765680831.
Texte intégralRésumé :
Book Summary:Latinos are the fastest growing population in America today. This two-volume encyclopedia traces the history of Latinos in the United States from colonial times to the present, focusing on their impact on the nation in its historical development and current culture. "Latino History and Culture" covers the myriad ethnic groups that make up the Latino population. It explores issues such as labor, legal and illegal immigration, traditional and immigrant culture, health, education, political activism, art, literature, and family, as well as historical events and developments. A-Z entries cover eras, individuals, organizations and institutions, critical events in U.S. history and the impact of the Latino population, communities and ethnic groups, and key cities and regions. Each entry includes cross references and bibliographic citations, and a comprehensive index and illustrations augment the text.
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Briem, Harry. « Entwurf und Implementierung einer Fokus-plus-Kontext-basierten (F+C-basierten) Tabelle ». Master's thesis, Universitätsbibliothek Chemnitz, 2007. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200700566.
Texte intégralRésumé :
Ein Kernbereich der Informationsvisualisierung ist
die effiziente, gleichzeitige Darstellung von Fokus
und Kontext. Hierfür wurden verschiedenste Methoden
in der Literatur vorgestellt, wenige auch in
Nutzertests analysiert. Eine viel versprechende
Methode ist die Einbindung der dritten räumlichen
Dimension wie sie die perspective wall
(Mackinlay et al. 1991) verwendet. Diese wird hier
genutzt, um tabellarische Darstellungen zu
optimieren. Die Vorteile des semantic zooming für
tabellarische Darstellungen wurden bereits von
(Reiterer et al. 2005) gezeigt. Hier werden beide
Ansätze kombiniert, mit zusätzlich Such- und
Filtermöglichkeiten versehen und in einem
Nutzertest evaluiert.
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Witt, Anette. « Synthetic development towards benzodiazepine alkaloids : total synthesis of circumdatin F and C / ». Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-077-6/.
Texte intégral
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Chia, Poh Wai. « The C-F bond as a conformational probe in agonist receptor interactions ». Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/2615.
Texte intégralRésumé :
Chapter 1 gives an introduction on the physical and electronic properties of fluorine and the C-F bond. The application of fluorine in organic chemistry, which is mainly attributed to the electronic properties of fluorine is described. The role of fluorine in neuropsychiatric drug development and for influencing the conformational study of bioactive amines is also illustrated. Chapter 2 of the thesis describes the synthesis of the two fluorinated stereoisomers (2R, 3S) and (2S, 3S) 3-fluoro N-methyl–D-aspartate (NMDA). These were prepared as analogues to study the binding conformation of NMDA on the glutameric NMDA receptor. The (2S, 3S)-3-fluoro NMDA D-72 was successfully prepared from diethyl D-tartrate. The (2S,3R)- stereoisomer was prepared by separation of diastereoisomers generated by reaction of a meso- epoxide with an enantiomerically pure amine, followed by fluorination. Both the (2S,3R)- and (2R,3S)- enantiomers were prepared separately, however assignment of the absolute configuration to each enantiomer could not be unambiguously proven. The fluorinated 3F-NMDA stereoisomers were assessed by dose response analysis and TEVC analysis in the rat glutamate receptor. The biological results show that the (2S, 3S)-3F NMDA D-72 is a good agonist, whereas (2R, 3S)- and (2S, 3R)-3-fluoro NMDA are inactive stereoisomers. The result of this study indicates that (2S, 3S)-3F NMDA D-72 is the only relevant agonist that can access a conformation for binding to NMDA receptor. Chapter 3 describes the preparation of fluorinated analogues of the calcium receptor agonist Cinacalcet. The (2R,1’R)-123 and (2S,1’R)-124 fluoro Cinacalcet diastereoisomers were prepared from 3’-(trifluoromethyl)cinnamic acid and 3’’-SF₅-137 Cinacalcet was synthesized from pentafluorosulfanyl benzyl alcohol. The biological assessment in the calcium receptor (CaR) revealed that both (2R,1’R)-123 and (2S,1’R)-124 fluoro Cinacalcet is slightly lower in potency compared to the non-fluorinated Cinacalcet 117. This suggests that the Cinacalcet 117 adopts an extended conformation when bound to the receptor. The 3’’-SF₅-137 Cinacalcet possesses equipotent activity with Cinacalcet 117.
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Boulter, Roger Stephen. « F C Erasmus and the politics of South African defence, 1948-1959 ». Thesis, Rhodes University, 1998. http://hdl.handle.net/10962/d1002386.
Texte intégralRésumé :
FC Erasmus became South Africa's defence minister in 1948 after two decades as a leading political organiser for the National Party. Although an architect of the Nationalists' post-war election victory he was not considered a minister of the first rank. Erasmus initiated a process of ridding the defence force of officers who he believed were associated with the Smuts government and replacing them with party supporters. As a result the military often lost experienced and talented officers. Erasmus felt that the armed services had been too British in ethos and appearance. He inaugurated tighter regulations on bi-lingualism, reintroduced boer rank titles, launched new uniforms and original medals and decorations, to the acclaim of the volk. His purpose was to have a defence force which was uniquely South African. Many of his policies came under attack not only from the United Party but also groups such as the Torch Commando and the veterans organisations. With the apparent lack of an imminent military threat to the apartheid government Erasmus never received substantial budgetary allocations from finance ministers. The defence force, one without conscription, remained small with largely antiquated equipment for the important air and land forces. However by the decade's end the navy was gradually receiving modern ships under the terms of the Simonstown agreement, which Erasmus had negotiated with Britain. The events of the Sharpeville crisis, just after Erasmus left defence, demonstrated that the armed forces as moulded by the minister were in poor condition to assist the civil power in suppressing disturbances. Overseas Erasmus hoped to increase the acceptability of the Union as a defence partner among Western countries by providing personnel for the Berlin Air Lift and the Korean conflict and promising a contingent for the Middle East. He attempted unsuccessfully to instigate anti-communist alliances for the land and maritime defence of Africa when the European powers were leaving the continent. These actions were primarily to obtain political support for the Union, whose prestige was rapidly decreasing as apartheid became better known. The external initiatives with the exception of the Simonstown naval agreements were not lasting.
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Wang, Ting. « Studies on Natural Products Phorboxazole A, Cephalosporolide E, F and Thuggacin C ». The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1316443941.
Texte intégral
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Grunenberg, Alfred Teo. « Separation of fluorocarbon gases from a reactor plasma system / Alfred Teo Grunenberg ». Thesis, North-West University, 2008. http://hdl.handle.net/10394/2640.
Texte intégralRésumé :
South Africa has natural resources in mineral feedstock containing gold, manganese, chromium, vanadium, copper, antimony, phosphate rock, uranium, fluorspar and titanium. A high percentage of these ores are exported in unbeneficiated form. There are beneficiation opportunities to transform the raw materials to value-added products, thus increasing employment and stimulating the South African economy.
Fluorocarbon (CxFy) gases can be produced via high-temperature plasma processes, where fluorspar and carbon (CaF2 + C) react at -6000K. These gases are traditionally separated by means of costly and unsafe cryogenic distillation.
The focus of this project is to propose a feasible separation process and to interlink it to a plasma system in order to develop a conceptual plant that can produce 2500 t/a C2F4 and 625 t/a C3F6 safely and cost-effectively, both with 96% purity.
To execute the above a literature survey was done giving vital information on absorption and distillation systems as well as membranes that can be used to separate CF4 from CxFy gas streams at acceptable pressures and temperatures.Thesis (M.Sc. Engineering Sciences (Chemical Engineering))--North-West University, Potchefstroom Campus,
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Lahlou, Safaâ. « Epidémiologie de l'hépatite C : prévalence dans le groupe hospitalier Lariboisière, F. Widal durant l'année 1998 ». Paris 5, 1999. http://www.theses.fr/1999PA05P198.
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Oberfeld, Benjamin. « F₁F₀ ATP synthase : Identification of a plug within the c-ring and heterologous expression of a sodium-translocating enzyme / ». Zürich : ETH, 2006. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16487.
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Park, Nathaniel H. (Nathaniel Hamilton). « Development of new transition metal catalysts for C-N bond formation and continuous flow processes for C-F bond formation ». Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/101553.
Texte intégralRésumé :
Thesis: Ph. D. in Organic Chemistry, Massachusetts Institute of Technology, Department of Chemistry, 2015.Cataloged from PDF version of thesis. Vita.
Includes bibliographical references.
The work presented in this dissertation addresses the development of new methodologies and processes to form carbon-nitrogen (C-N) and carbon-fluorine (C-F) bonds. The development of methods for the formation of C-N and C-F bonds are highly important to chemistry in general and find broad application in many different areas of research. With regard to C-N bond formation, the development of new nickel and palladium catalyst for C-N cross-coupling is presented. Finally, the development of a new process to enable the rapid preparation of aryl fluorides via the Balz-Schiemann reaction is explored. Chapter 1. Development of an Air-Stable Nickel Precatalyst for the Amination of Aryl Chlorides, Sulfamates, Mesylates, and Triflates. A new air-stable nickel precatalyst for C-N cross-coupling is reported. The developed catalyst system displays a greatly improved substrate scope for C-N bond formation to include both a wide range of aryl and heteroaryl electrophiles and aryl, heteroaryl, and alkyl amines. The catalyst system is also compatible with weak base, allowing for the amination of substrates containing base-sensitive functional groups. Chapter 2. Design of New Ligands for the Palladium-Catalyzed Arylation of a- Branched Secondary Amines. In Pd-catalyzed C-N cross-coupling reactions, a-branched secondary amines are difficult coupling partners and often produce low yields of the desired product. To provide a robust method for accessing N-aryl a-branched tertiary amines, new catalysts have been designed to suppress undesired side reactions often encountered when these amine nucleophiles are used. These advances enabled the arylation of a wide array of sterically encumbered amines, highlighting the importance of rational ligand design in facilitating challenging Pd-catalyzed cross-coupling reactions. Chapter 3. Rapid Synthesis of Aryl Fluorides in Continuous Flow via the Balz- Schiemann Reaction. The synthesis of aryl fluorides (ArF) is of critical importance for the development of new and potent pharmaceuticals and agrochemicals. While there have been numerous and intense research efforts focused on developing new fluorination methods, the Balz-Schiemann reaction remains a valuable and efficient means of aryl C-F bond construction from a vast pool of available aryl amines. However, the harsh reaction conditions, modest yields, and often prohibitive safety concerns have limited the general application of this methodology. Here, we have developed a semi-flow process that enables safe handling of the potentially explosive aryl diazonium salt intermediates as well as improved yields of the desired aryl fluoride products. This process has been demonstrated on an array of different aryl and heteroaryl amine substrates containing a variety of different functional groups.
by Nathaniel H. Park.
Ph. D. in Organic Chemistry
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Perálvarez, Marín Alejandro. « Dynamic Factors of Bacteriorhodopsin : Regulation Key Points in Helices B, C and F ». Doctoral thesis, Universitat Autònoma de Barcelona, 2005. http://hdl.handle.net/10803/3542.
Texte intégralRésumé :
The main objective of this work is the analysis of the structural and functional role of some amino acids in Bacteriorhodopsin.- Characterization of the motif Thr90-Pro91 in the centre of Helix C of Bacteriorhodopsin. Because Thr90 interacts with Asp115 through a hydrogen bond and with the retinal through hydrophobic interaction, the mutants T90V and D115A were taken into account. The following objectives were settled:
Design and construct the Bacteriorhodopsin mutants P91A, T90A,T90V and D115A by site directed mutagenesis.
Express the mutants in the purple membrane of Halobacterium salinarum.
Analyze the role of Thr90 and Pro91 in the properties of the protein and in the proton pumping function in particular through the study of the mutants.
Infer a role to the motif Thr90-Pro91 in Bacteriorhodopsin.
- Analyze the role of the other two Prolines located in transmembrane helices in BR, and to extend this role to other Transmembrane Proteins. The subsequent objectives were proposed:
Design and construct the Bacteriorhodopsin mutants P50A and P186A by site directed mutagenesis.
Express the mutants in the purple membrane of Halobacterium salinarum.
Characterize the role of Pro50, and Pro186 in Bacteriorhodopsin properties and proton pumping through the analysis of the mutants.
Infer a role to Helix-embedded prolines of Bacteriorhodopsin in particular and to transmembrane helices of proteins in general.
50
Haddadian, Esmael Jafari. « Brownian dynamics study of cytochrome f / Rieske interactions with cytochrome c₆ and plastocyanin ». Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1123695434.
Texte intégralRésumé :
Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xxiii, 184 p.; also includes graphics (some col.). Includes bibliographical references (p. 169-184). Available online via OhioLINK's ETD Center