Dissertations / Theses: 'Alkemy'

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Phung, Toan, and Toan Phung@gmail com. "An Historical Based Adaptation Mechanism For BDI Agents." RMIT University. Computer Science and Information Technology, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080515.124049.

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One of the limitations of the BDI (Belief-Desire-Intention) model is the lack of any explicit mechanisms within the architecture to be able to learn. In particular, BDI agents do not possess the ability to adapt based on past experience. This is important in dynamic environments as they can change, causing previously successful methods for achieving goals to become inefficient or ineffective. We present a model in which learning, analogous reasoning, data pruning and learner accuracy evaluation can be utilised by a BDI agent and verify this model experimentally using Inductive and Statistical learning. Intelligent Agents are a new way of developing software applications. They are an amalgam of Artificial Intelligence (AI) and Software Engineering concepts that are highly suited to domains that are inherently complex and dynamic. Agents are software entities that are autonomous, reactive, proactive, situated and social. They are autonomous in that they are able to make decisions on their own volition. They are situated in some environment and are reactive to this environment yet are also capable of proactive behaviour where they actively pursue goals. They are capable of social behaviour where communication can occur between agents. BDI (Belief Desire Intention) agents are one popular type of agent that support complex behaviour in dynamic environments. Agent adaptation can be viewed as the process of changing the way in which an agent achieves its goals. We distinguish between 'reactive' or short-term adaptation, 'long-term' or historical adaptation and 'very long term' or evolutionary adaptation. Short-term adaptation, an ability that current BDI agents already possess, involves reacting to changes in the environment and choosing alternative plans of action which may involve choosing new plans if the current plan fails. 'Long-term' or historical adaptation entails the use of past cases during the reasoning process which enables agents to avoid repeating past mistak es. 'Evolutionary adaptation' could involve the use of genetic programming or similar techniques to mutate plans to lead to altered behaviour. Our work aims to improve BDI agents by introducing a framework that allows BDI agents to alter their behaviour based on past experience, i.e. to learn.

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Régent, Damien [Verfasser], and Bernhard [Akademischer Betreuer] Breit. "Rhodium-catalyzed intra- and intermolecular alkene hydroacylation = Rhodium-katalisierte Intra- und Intermolecular Alken Hydroacylation." Freiburg : Universität, 2014. http://d-nb.info/1115813811/34.

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Bräuner, Maja. "Alkemi och jungiansk psykologi." Thesis, University of Gävle, Ämnesavdelningen för kultur- och religionsvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-6707.

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This assignment is a venture into the use of the concept alchemy in the texts on analytical psychology written by Carl G. Jung. Originally the idea was to compare the blending of colours in art painting with the Jungian understanding of alchemy. In order to understand the many and it seems differentiated correlations to alchemy in the texts on analytical psychology written by C.G. Jung, I have found it necessary to investigate the history of alchemy in modern Europe and the Egyptian figure of Hermes Trismegistos. This helps shedding light on Jung’s manner of writing in his texts on analytical psychology.

The assignment includes an understanding of colours as understood by Goethe as well as the aspect of alchemy in the Rosicrucian movement and the kabbalah. The Jungian aspects of world religions are in this context emphasized as well as the use of symbols and symbolic speech.

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Szuromi, Endre. "Alkene-oxo and alkene-alkene coupling on Pt(II)." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4156.

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Thesis (Ph. D.)--University of Missouri-Columbia, 2005.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (November 14, 2006) Vita. Includes bibliographical references.

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García, Ruiz Víctor M. "Studien zur Anwendung der Olefinmetathese." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=962929832.

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Husain, A. H. "Mechanism of alkene epoxidation." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604836.

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Heterogeneous silver catalysed ethene epoxidation is a strategically important selective oxidation giving rise to ethene epoxide a versatile monomer that is largely converted to glycols and used as antifreeze. Several aspects of this commercially important reaction were investigated using electrochemical promotion, a technique which involves electropumping of ions from a solid ion-conducting electrolyte to the surface of a porous catalytically active metal film. The most notable result in this work from ethene epoxidation was the elucidation of the NO_xpromotion effect. It was shown that adsorbed alkali and parts per million levels of nitric oxide added in the gas feed were minimum and sufficient conditions for the appearance of this phenomenon. Another commercially daunting and scientifically challenging reaction that was studied in this work was the heterogeneous propene epoxidation on silver catalysts. Using electrochemical promotion this work has shown that ethene and propene epoxidation react in a very different and contrasting manner to the addition of cholorine (CI), alkali and nitric oxide (NO) promoters. Basically potassium (K) alone is bad for ethene epoxide (EO), good for propene epoxide (PO), CI is good for EO, indifferent for PO, K+CI is good for EO, bad for PO and K+NO is good for EO, bad for PO. X-ray photoelectron spectroscopic investigation of the silver catalyst revealed that the substantially different state of oxygenation of the silver subsurface region could be the origin of the very different selectivity observed with these two alkenes. The underlying reason for the observed promotion in selectivity with adsorbed chlorine in ethene epoxidation was investigated by studying the effect of all four halogen promoters’ viz., fluorine, chlorine, bromine and iodine on supported silver on alumina catalysts. It was found that chlorine is the best promoter amongst them all. The behaviour of the halogens had a direct bearing to their electron affinity. And it seems that electronic affects are at work and geometric effects due to site blocking can be ruled out.

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7

Hudson, Richard D. A. "Alkenyl-extended cyclohexadienyl complexes." Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309965.

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8

Richardson, Guy Norbury. "#mu#-alkenyl diruthenium chemistry." Thesis, University of Bristol, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260516.

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9

Pullin, Robert David Charles. "Amine-promoted alkene aziridination." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/6939.

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Aziridines, the smallest saturated aza-heterocycle, are not only prevalent in several natural products, but also represent a versatile synthetic tool for the chemist via exploitation of the strained ring system. Research described in this thesis concerns the chemistry of N-N ylides (aminimines), which were utilised in a novel tertiary amine-promoted organocatalytic approach to the aziridination of α,β-unsaturated carbonyl compounds. Through the use of modified conditions two important classes of substrates, dienones and alpha-enolizable enones, both of which had previously shown poor reactivity with the system, can now be aziridinated in good yields. Studies have also focused on the development of an asymmetric variant of the methodology using chiral tertiary amine promoters. A variety of novel chiral six-membered 1,4-heterocycles and cinchona alkaloid derivatives have been synthesised and their utility towards asymmetric alkene aziridination has been assessed, aiding the understanding of the proposed transition state model for the reaction.

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Knoke, Stefan. "Video- und elektronenmikroskopische Untersuchungen der Olefinpolymerisation mit trägerfixierten Katalysatorsystemen." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=973585625.

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Karlsson, Thomas. "Götisk kabbala och runisk alkemi : Johannes Bureus och den götiska esoterismen." Doctoral thesis, Stockholms universitet, Institutionen för etnologi, religionshistoria och genusstudier, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-37152.

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Gothicism in general, and the Swedish Gothicism in particular, had a close connection to the esoteric currents that were flourishing all over Europe in the Early Modern Period. Apocalyptic predictions and prophecies useful to Gothic propaganda were derived from contemporary esoteric streams, but alongside these came Hermetic and Neo-Platonic speculations of a more individual character that emphasized man’s gradual ascension toward a higher state. The foremost representative for this union of Gothicism and Esotericism was Johannes Bureus (1568-1652). Although a pioneer of runology and Swedish grammatical studies, Bureus felt he made his greatest contributions in the sphere of mysticism. Influenced by the concept of a Philosophia Perennis, Bureus believed this eternal philosophy was not only expressed by the ancient Greeks, Egyptians, and Hebrews, but also by the ancient Norse. Bureus represents what could be termed an Esoteric Gothicism. In his work, the ideal of Gothicism melds with Esotericism in the form of Alchemy, Kabbalah, Hermeticism, Astrology, and Magic. Bureus himself called his esoteric system a Nordic Kabbalah, a “Notaricon Suethica,” or a “Kabala Upsalica.” Bureus’s Esotericism is explicated primarily in his manuscripts such as the Cabbalistica, Antiquitates Scanziana, and especially Adulruna Rediviva (the latter produced in seven versions over a forty-year period), but also in his major opus, dedicated to his pupil Queen Christina, the printed apocalyptic book Nordlanda Lejonsens Rytande. In examining Esoteric Gothicism we can discern a further tendency within Gothicism beyond the national chauvinism typically seen as exemplifying the movement. In Bureus’s work, Gothic motifs are combined with runes and Old Norse themes in an imaginative manner, but most characteristic of Bureus is how he uses the results to describe a highly individual path of initiation which leads to unity with God. Bureus’s ideas may seem eccentric to a modern reader, but properly situating them in their historical context reveals the role he played in an influential current in European intellectual and spiritual history, a current often referred to by scholars as Western Esotericism.

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Karlsson, Thomas. "Götisk kabbala och runisk alkemi Johannes Bureus och den götiska esoterismen /." Stockholm : Institutionen för etnologi, religionshistoria och genusstudier, Stockholms universitet, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-37152.

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13

Malumbazo, Nandi. "Immobilized catalysts for alkene oxidation." Thesis, University of the Western Cape, 2007. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_1206_1257925149.

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Tertiary butyl substituted and unsubstituted Schiff base systems containing N,O donor ligands (Salicylaldimines) with aminotriethoxysilane tail were synthesized and complexed to Copper and Cobalt acetate. In this study, the effect of metal, reaction time, nature of oxidant (hydrogen peroxide tertiary butyl hydroperoxide), substituents on thel igand and substrate concentration, were investigated.

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Kölling, Lars. "Neue Diimidochrom(VI)- und Diphosphoraniminatotitan(IV)-Chelatkomplexe metallocen-alternative Katalysatoren für die Olefinpolymerisation /." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=966024745.

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15

Mahelová, Zora. "Charakterizace chemického složení dehtu po zplyňování biomasy." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240964.

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Biomass is a renewable source of energy and represents an acceptable alternative to fosil fuels. Usable methods of energetic use of biomass are combustion and gasification. Main interest is focused on gasification in last years. Gasification is based on conversion of organic material to usable gaseous product called syngas, which can be used as a fuel for energy production. Large amount of tar is formed as a by-product of incineration and gasification of biomass. Tar is composed by various mixture of organic substances, has a negative effect on operating conditions and is a potential threat to environment. Experimental part of this study was focused on analysis of tar obtained by gasification of various kind of biomass. Selected groups of hydrocarbons and oxygen compounds were identified in analysed samples. Individual biomass samples were compared regarding to determined relative content of selected substances. Analysis was done by complete twodimensional gas chromatography with mass spectrometric detection (GCxGC/TOF-MS).

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16

Yildiz, Ünveren Hesna Hülya. "Hydroformylation of long chain olefins in microemulsion." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972892109.

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Todadze, Ekaterina. "Die silberkatalysierte Gasphasenepoxidation von Alkenen." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=97167017X.

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Weingarten, Ulrich. "Homo-, Co- und Terpolymerisation von Ethen, Propen und Dien mit Metallocen-, MAO-Katalysatoren." [S.l. : s.n.], 2000. http://www.sub.uni-hamburg.de/disse/373/Diss.pdf.

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19

Beulich, Inken. "Copolymerisation von Ethen und sterisch anspruchsvollen Olefinen durch Metallocen-Katalysatoren." [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=957827113.

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20

Büchner, Michael. "FT-ICR-massenspektrometrische Untersuchungen: Gasphasen-Reaktivität ionisierter Halogenalkene gegenüber Nukleophilen." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=960862498.

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21

Reuter, Sebastian. "Katalytische Dihydroxylierung funktionalisierter Olefine in der asymmetrischen Synthese." [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=960869107.

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22

Frunzke, Jan. "Quantenchemische Untersuchungen an übergangsmetallkatalysierten Oxidationsreaktionen die Oxidation von Alkenen mit Rutheniumtetraoxid /." [S.l. : s.n.], 2003. http://archiv.ub.uni-marburg.de/diss/z2003/0190/.

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23

Miyagawa, Christian. "Rhodiumkatalysierte Hydroformylierung höhermolekularer Olefine in Mikroemulsionen." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965381242.

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Möller, Klaus. "Entwicklung von neuen Olefin-Polymerisationskatalysatoren für die automatisierte Evaluierung." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971304335.

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25

Uherek, Elmar. "Laboruntersuchungen der mechanistischen Bildung von Carbonsäuren in der Ozonolyse von Alkenen und ihrer Rolle bei der Aerosolbildung." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=971569029.

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26

Zipp, Alexander. "Metathese von 1-Buten an Rheniumoxidkatalysatoren." Phd thesis, [S.l. : s.n.], 2005. https://tuprints.ulb.tu-darmstadt.de/568/1/diss_zipp_a.pdf.

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Im Rahmen der Arbeit wurde die Desaktivierung hochaktiver Rheniumoxid-Trägerkatalysatoren (Re2O7/γ-Al2O3) bei der Metathese von 1-Buten zu den Hauptprodukten Ethen und 3-Hexen in flüssiger Phase untersucht. Die Reaktion ist nicht nur im Hinblick auf eine Umsetzung des als Nebenprodukt beim Steam-Cracken anfallenden 1-Butens zu wertvolleren Produkten interessant, sondern ist auch als eine generelle Beispielreaktion für Umwandlung petrochemisch erzeugter Alkene zu sehen (OCT, von engl. Olefin Conversion Technology). Die Untersuchungen wurden in einer speziellen Versuchsapparatur mit einem so genannten Spinning-Basket Reaktor unter dem Einsatz sowohl industrieller als auch selbst präparierter Katalysatoren durchgeführt. Durch die Experimente gelang es die Desaktivierung der Katalysatoren unter dem Einfluss verschiedenster Parameter, wie den Betriebsbedingungen oder unter Beigabe zahlreicher Zusätze zu untersuchen. So konnte beispielsweise gezeigt werden, dass die Desaktivierung durch die Zugabe kumulierter Diene und organischer Basen stark beschleunigt werden und ihre Geschwindigkeit durch die Zugabe von Ethen oder Wasserstoff signifikant verringert werden kann. Im Rahmen der kinetischen Modellierung der Daten wurde ein komplexes chemisches Modell aufgestellt, das mit den experimentellen Ergebnissen in Einklang steht. Die daraus erhaltenen Geschwindigkeitskoeffizienten bestätigen die qualitativ gefundenen Ergebnisse. Ergänzend zu den kinetischen Messungen wurden infrarotspektroskopische Untersuchungen unter Einsatz der Diffusen-Reflexions-Infrarot-Fourier-Transformations-Spektroskopie (DRIFTS) zu den Ursachen der desaktivierenden Reaktion(en) durchgeführt. Das Bandenwachstum in den zeitlich veränderlichen Spektren zeigt eine offensichtliche Korrelation mit den kinetischen Ergebnissen. Die Zuordnung der Bandenlagen zu potentiellen Schwingungsmodi konnte aufgrund der systemimmanenten Komplexität noch nicht vollständig aufgeklärt werden, dennoch scheint mit der DRIFTS die direkte Untersuchung der desaktivierenden Prozesse möglich zu sein. Möglicherweise können mit dieser Technik wertvolle Hinweise auf den Mechanismus der Desaktivierung gewonnen werden, mit dessen Kenntnis gegebenenfalls rationelle Strategien zur Vermeidung der Desaktivierung möglich sein könnten.

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27

Reeves, Jonathan Robert. "Alkene epoxidation using small ring heterocycles." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397377.

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28

Hamid, S. A. "A mechanistic study of alkene hydrogenation." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603611.

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The work described in this thesis explores the influence of the nature of transition metals, the electronic properties of ligands and the effect of counter-ions in the regioselectivity of transition metal-hydride addition (hydrometalation) to carbon-carbon double bonds. The method used to investigate the regioselectivity of the hydrometalation was based on the established methodology [Mode a (M^δ+ - H^δ-) and Mode b (M^δ- - H^δ+)]. The cis-alkenes were subjected to hydrogenation using deuterium gas. Following the hydrometalation step, the rotation of one end of the substrate would give a trans-conformation, which would transform to the trans-isomer via β-hydride elimination. The location of the deuterium on the double bond would indicate the regioselectivity of the hydrometalation. Chapter 2 investigates the intrinsic nature of transition metal-hydrides, namely Pd/C, Pt/C and Rh/C. The behaviour of each M-H addition to the double bond of alkenes is compared, in an attempt to reveal the periodic trend in the transition metals. Information on the nature of these catalysts would be useful for modification of the catalysts in order to improve selectivity. Chapter 4 demonstrates the effect of the electronic properties of ligands in controlling the regioselectivity of hydrometallation. Wilkinson's catalyst is taken as a model system. A range of ligands bearing different electron-withdrawing and electron-donating substituents are synthesized and are then used to make Wilkinson's type catalysts. These catalysts are used in the hydrogenation of cis-β-methoxystyrene using deuterium gas. The implication of the findings for chiral induction is discussed. Chapter 5 describes an extension of the methodology to another class of catalyst, Ir-phosphinooxazolines. These complexes have been shown to be efficient catalysts for the asymmetric hydrogenation of alkenes. The effect of the counter-ions of the complexes on the regioselectivity of the hydrometalation is investigated.

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29

Rodenhurst, Paul Raymond. "Chemistry of diruthenium #mu#-alkenyl complexes." Thesis, University of Bristol, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385308.

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30

Gopalakrishnan, Sandhya. "Electronic spectroscopy of the alkoxy radicals." Columbus, OH : Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1051024461.

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Thesis (Ph. D.)--Ohio State University, 2003.
Title from first page of PDF file. Document formatted into pages; contains xxiv, 173 p.: ill. (some co.). Includes abstract and vita. Advisor: Terry A. Miller, Dept. of Chemistry. Includes bibliographical references (p. 171-173).

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31

Krug, John P. "The mechanisms of enone-alkene photocycloaddition reactions." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq21299.pdf.

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32

Raymond, Jeffery R. "Exocyclic alkene synthesis via stereoselective radical cyclizations." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25143.pdf.

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33

Bijpost, Erik Alexander. "Alkene conversions with early transition metal catalysts." [S.l. : [Groningen] : s.n.] ; [University Library Groningen] [Host], 1996. http://irs.ub.rug.nl/ppn/153266457.

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34

Vessey, Jonathan Dennis. "Hydride, alkene and vinyl complexes of ruthenium." Thesis, University of York, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.483971.

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35

Wasseyehun, Kelemu Solomon. "New Metallosupramolecular Assemblies Involving Silver-Alkene Interactions." Thesis, University of Canterbury. Chemistry, 2012. http://hdl.handle.net/10092/7871.

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This thesis describes the silver(I) coordination chemistry of forty two ligands containing alkene functional group. The synthesis of thirty nine ligands is described, fourteen of which were previously unreported compounds. These ligands are classified into three major categories containing allyloxy, diallylamine and allyl groups. The ligands containing allyloxy groups were designed by changing the number of allyloxy arms from one to six, which allows investigation of the influence of the number of allyloxy arms within a ligand on the overall structure of the complex. Ligands containing one allyloxy arm generally form rectangular shaped discrete assemblies that involve the coordination of the nitrogen atom of the core and the allyloxy arm of the ligand with silver. Ligands containing two and three allyloxy arms gave 1D and 2D polymeric structures. Some of these 2D polymers contain cavities filled by the counter anion and the solvent used to grow crystals of the complex. Some of the ligands containing four allyloxy arms gave discrete M₂L or M₄L₂ type coordination complexes. One of these ligands gave a rare type of 1D-1D polycatenane by intercalating two ladders. A ligand containing six allyloxy arms forms a 1D polymeric assembly by using the six allyloxy arms and four silver atoms. Four of these allyloxy arms chelated, while the other two are bridging. Ligands containing two, four and six allyl arms were designed by using diallylamine groups. Introducing additional functional groups in the core structure of the ligand showed the co-existence of silver(I)-alkene interactions with other strong interactions, such as silver(I)-nitrogen. Ligands containing one diallyamine group with different silver(I) salts resulted in 1D polymeric assemblies, while two and three diallylamine groups inclined to form M₂L, M₃L and M₄L₂ discrete assemblies. Ligands containing allyl groups with a urea core structures showed the coexistence of silver(I)-alkene interaction with other moderate interactions such as silver(I)-carbonyl oxygen. The use of ligands containing allyl group allowed the formation of 1D polymeric ladders and helical structures as well as discrete assemblies. ¹H NMR spectroscopy, ¹³C NMR spectroscopy, mass spectrometry, IR, melting point and X-ray crystallography were used to study the compounds synthesised. The crystal structure of six ligands, forty-six complexes and two salts are discussed.

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36

Turner, Thomas P. W. "Bifunctional unsymmetrical ditopic ligands for alkene methoxycarbonylation." Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658207.

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A series of unsymmetrical xylenyl-backboned diphosphine ligands are reported: o-C6H4(CH2ptSU2)(CH2PRR'), R = Ph, R' = 2-Py (L1) and O-C6H4(CH2ptSU2)(CH2PR2), R = 2-Py (L2), R = 2-(3-Me-Py) (L3), R = 2-(4- Me-Py) (L4), R = 2-(6-Me-Py) (Ls) and R = 2-Pyrim (Ls). The ligands have all been characterised by 31p, 1H and 13C NMR spectroscopy and high resolution mass spectrometry. Studies of [PtCI(CH3)(L)] and [PdCI(CH3)(L)] (L = L1-LS) have shown that the favoured isomers have the more strongly a-donating CH3 ligand trans to the bulkier ptSU2 donor. Studies with [PdCI2(L)], [PtCI2(L)] and [Pt(CH3h(L)] (L = L1-LS) show that the donor strength of the two phosphorus centres is not averaged in these complexes, in contrast to the related complexes of o-C6H4(CH2ptSu2)(CH2PPh2) (TP). These complexes have been characterised by a combination of NMR spectroscopy, high resolution mass spectrometry, elemental analysis and X-ray crystallography. The coordination chemistry of PR3, R = 2-(3-Me-Py), R = 2-(4-Me-Py), R = 2-(6-Me-Py), with LiCI and LiSr is also reported. Tripodal coordination to lithium by the three pyridyl nitrogen donors is detected for each ligand. These [LiX(PR3)] complexes have been characterised by 31p, 1H and 13C NMR spectroscopy and X-ray crystallography. Protonation studies with [PdCI2(L)] and [PtCh(L)] (L = L1-LS) suggest that the pendant pyridyl and pyrimidyl groups of L1-LS are protonated in methanolic solutions when treated with acids such as HSF 4, CH3S03H (MSA) and CF3C02H (TFA). The evidence for protonation came from 31p NMR spectroscopy and X-ray crystallography. Protonation studies with [Pt(CH3h(L2)] have shown that tridentate coordination of platinum by L2 (through both P donors and one pyridyl N donor) occurs. Catalysts derived from the new ligands were tested in the palladiumcatalysed methoxycarbonylation of ethene. The systems based upon L1, L2, L4 and Ls are shown to be active and selective for the production of methyl propionate (MeP) over polyketone (PK). Those derived from L2 and Ls are comparable in activity to the best reported system (which is based upon o-C6H4(CH2ptSU2h, dtbpx) when promoted by the strong acid MSA. The L2 and Ls systems are more active than dtbpx with the weaker acids TFA and PA. Complexes derived from L3 and Ls are inactive in methoxycarbonylation catalysis. Catalysts derived from L1-LS are also shown to be active in palladium-catalysed styrene methoxycarbonylation. Mechanistic studies suggest that catalysts derived from L2 produce MeP following the hydride mechanism. Competition between the coordination of palladium by the nitrogen donor of a pendant pyridyl group and acid anions was observed under catalytically relevant conditions. Complexes derived from L3 appear to be inactive in MeP catalysis due to persistent tridentate coordination of palladium (via the two P donors and one pyridyl N donor) blocking substrate coordination. Complexes derived from Ls may be inactive in MeP catalysis due to the electron deficient nature of the PPyrim2 donor. Carbonylation studies with isotopically labelled 13CO support the conclusion that MeP preference is a balance between kinetic and thermodynamic influences - the minor palladium-ethyl complex isomer may react faster to generate the more stable palladium-acyl isomer.

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37

Jones, Alexander. "Mechanistic studies of enantioselective alkene bromolactonisation reactions." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/24940.

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Asymmetric alkene halofunctionalisation is a vibrant and rapidly expanding field. Several promising organocatalysts have emerged based on privileged binaphthyl phosphoric acid and cinchona alkaloid scaffolds. However, there is still significant potential for improvement. Many catalyst systems are limited in substrate scope and mechanistic understanding. In this thesis we describe the development of asymmetric bromolactonisation reactions catalysed by bis-cinchona alkaloid, (DHQD)2PHAL, as modified by added carboxylic acids. This combination delivers bromolactones with enantioselectivity at a comparable level to bespoke organocatalysts previously optimised for particular substrate classes. The utility of our system is based on the commercial availability of all reagents and the ability to tune the performance of (DHQD)2PHAL with reaction additives. The mode of substrate activation and the role of the carboxylic acid additive are investigated. Asymmetric induction is strongly influenced by the concentration and the stereoelectronic properties of the additive, and enantioselectivity deteriorates with reaction conversion in its absence. Interactions between carboxylic acids and (DHQD)2PHAL are characterised by crystallographic and equilibrium 1H NMR analysis. 2D-NOESY experiments indicate that acids significantly restrict the rotational flexibility of (DHQD)2PHAL in solution. We propose that catalyst rigidity is essential for maximisation of enantioselectivity. This hypothesis leads to the development of conformationally constrained catalyst derivatives which catalyse bromolactonisation with greater enantioselectivity than (DHQD)2PHAL. The relative stereoselectivities of successive alkene bromination and cyclisation steps, and the configurational stability of intermediate bromonium ions are elucidated. An unusual scenario is encountered whereby product e.r. is also determined by the regioselectivity of lactonisation. Finally, a unifying model for asymmetric induction is proposed which accounts for the absolute product configurations observed.

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38

Ross, Jennifer Nicola. "Alkoxy- substituted aryl- and benzyl- organotin compounds." Thesis, University of Aberdeen, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324880.

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New organotin compounds containing alkoxy- functionalities have been prepared. The methods of preparation of the tetraorganotin species have involved three routes. Hydrostannation reactions using triphenyltin hydride have resulted in the synthesis of triphenyltin derivatives of a series of alkoxy- substituted allyl ethers. The addition of tin IV chloride, diphenyltin dichloride and phenyltin trichloride to alkoxy- substituted aryl- and benzyl- Grignard reagents have also been successful. Alkoxy- substituted benzyltin compounds have been prepared by following an alternative preparation of benzylmagnesium halides from that commonly used to prepare Grignard reagents. Nucleophilic substitution of (iodomethyl)triphenyltin by a novel ligand has been effective. The structures of the products have been investigated by ¹H, ¹³C and ¹¹⁹Sn nmr. Single crystal X-ray diffraction studies have led to the determination of the crystal structures of tetra-2-anisyltin, tetrakis-(2-methoxybenzyl)tin and N,N'-bis(5-triphenylstannoxymethyl-2-phenyl-1,3-dioxan-5-yl)ethanediamide. Selective tin-carbon bond cleavage has been effected by the use of iodine and bromine to give rise to mono- and dihalo- organotin compounds and the crystal structures of tri-2-anisyltin iodide and di-2-anisyltin dibromide have been elucidated by X-ray crystallography. Chloro(3-ethoxypropyl)diphenyltin has been synthesised directly from diphenyltin dichloride and has been found to contain a penta-co-ordinate tin centre with a four membered chelate ring as a result of intramolecular tin-oxygen co-ordination. Other tin-carbon bond cleavage reactions by halogens have been studied by ¹H and ¹¹⁹Sn nmr and GLC and the results discussed.

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39

Reginato, Gloriana. "Asymmetric alkene epoxidation catalysed by chiral metalloporphyrins." Thesis, University of York, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298444.

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40

Wadman, S. N. "Stereoselective alkene syntheses from cyclic enol ethers." Thesis, University of Southampton, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233924.

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41

Daud, Wan Rosli Wan. "The mechanism of alkenyl succinic anhydride sizing." Thesis, Online version, 1988. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.329373.

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42

Williams, Paul John. "Studies on alkene aziridination using 3-acetoxyaminoquinazolinones." Thesis, University of Leicester, 1995. http://hdl.handle.net/2381/33999.

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Oxidation of 3-aminoquinazolinones with lead(IV) acetate in dichloromethane at -20 C gives the corresponding 3-acetoxyaminoquinazolinone. These intermediate 3-acetoxyaminoquinazolinones bring about the aziridination of a wide range of alkenes in good yields. The n.m.r. spectra of these 3-acetoxyaminoquinazolinones shows that there is chirality associated with the acetoxyamino group. Some of the work described in this thesis shows that this chirality arises from retarded rate of inversion at the exocyclic nitrogen on the n.m.r. time scale but that N-inversion at this nitrogen is fast on the time-scale of aziridination. This was accomplished by dynamic n.m.r. spectroscopic studies using 3-aIkoxyaminoquinazolinones and by comparison of diastereoselectivity in inter- and intramolecular aziridination studies using 3-amino-2-(1 -methyl-4-phenylbut-3-en-1-yl) aminoquinazolinone. The remainder of the thesis describes experiments which were designed to show the preferred configuration of the tetrahedral 3-acetoxyamino group in the transition state for aziridination: a knowledge of the location of the acetoxy group on nitrogen was considered a pre-requisite for the rational design of 2-substituted-3-acetoxyaminoquinazolinones for reagent-controlled aziridination of prochiral allcenes. From the preferred sense in diastereoselectivity in the aziridination of 4-substituted-4-hydroxycrotonates and l-substituted-2-methoxycarbonylprop-2-en-1-ols, a mechanism was proposed for aziridination of electron-deficient alkenes which comprises a Michael addition of the acetoxyamino nitrogen to the -position of the alpha,beta-unsaturated ester running ahead of an SN2-type substitution on the acetoxyamino nitrogen by the alkene (see below): this requires an anti relationship between the N-acetoxy group and the quinazolinone carbonyl group. For the analogous phenyl-substituted alkenes, the sense of diastereoselectivity was in agreement with a similar mechanism but with a reversal of the order in which the two aziridine bonds are made (see below) and hence with the requirement for a configuration of the acetoxyamino group syn to the quinazolinone carbonyl group. The application of these models to an aziridination involving double asymmetric induction accounts for the high stereoselectivity using an electron-deficient alkene but low diastereoselectivity using an analogous electron-rich alkene.

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43

Fordred, Paul. "Synthetically useful alkene isomerisation and hydroboration reactions." Thesis, University of Bath, 2012. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558880.

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Upon treatment with a palladium catalyst and hydrogen gas in the presence of caesium carbonate, a wide range of exomethylenic allylic alcohols were found to afford their corresponding trisubstituted isomers. Although hydrogenation was an unavoidable competing pathway, careful monitoring of the reaction progress allowed the desired isomerised products to be obtained in moderate to excellent yields and high (E):(Z) ratios.

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44

Caya, Thomas Charles. "Diastereoselective, Alkoxide-Directed Diborations of Alkenyl Alcohols." Thesis, Boston College, 2014. http://hdl.handle.net/2345/3859.

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Thesis advisor: James P. Morken
The metal-catalyzed diboration of alkenes has gained fame as a practical methodology for use in the stereoselective construction of complex organic molecules and synthetic building blocks. The created carbon-boron bonds have tremendous versatility and can easily be manipulated into carbon-carbon or carbon-heteroatom bonds. Unfortunately, metal-catalyzed diborations often suffer from limitations such as substrate specificity. To address these issues, we investigated diboration reactions in the absence of transition-metal catalysts. Herein is presented a transition-metal-free, diastereoselective diboration methodology utilizing alkenyl alcohols as substrates. Allylic alcohols can be treated with an organolithium base and bis(pinacolato)diboron to generate 1,2,3-triols upon oxidation. Most studies were done on homoallylic alcohols, which can be performed using a carbonate base and an alcohol additive. This methodology has many strengths, such as a wide substrate scope and high levels of diastereoselectivity. Further investigations into product functionalization and synthetic applications will be pursued in due time
Thesis (MS) — Boston College, 2014
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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45

Blagbrough, Tamzin C. "Alkene hydrogenation catalysed by dinuclear rhodium complexes." Thesis, Kingston University, 1990. http://eprints.kingston.ac.uk/20533/.

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The work reported in this thesis is concerned with two separated but related studies. The first involved examination of hydrogenation reactions of alkenes, dienes and alkynes using (Rh[sub]2C1(CO)[sub]2(dppm)[sub]2JBPh[sub]4 as a catalyst. Kinetic studies have been performed on the reaction of hexene. The system only well-behaved in the presence of a base, R[sub]3N, where a rst order dependance on both catalyst and hydrogen concentations observed. The order with respect to alkene is of the Michaelis-Menton type. This behaviour suggests that the active catalyst is a neutral monohydride generated by deprotonation of a ionic dihydride. It is proposed that the active catalyst is a dinuclear species, since none of the likely mononuclear breakdown oducts shows any catalytic activity. A catalytic cycle for the reaction is proposed. The second study was an investigation into the use of fast atom bombardment (FAB) mass spectrometry as a means of anaylsis organometallic compounds which have proved difficult to identify using other ionisation modes. The technique was shown to informative spectra for a series of dinuclear rhodium-dppm mplexes and some dinuclear manganese carbonyl derivatives. FAB ionisation also proved effective for identification of phosphine and phosphite derivatives of [RCC0[sub]3(CO)[sub]9.] (R=CH[sub]3, C1). The technique was also combined with thin layer chromatography (TLC) in examining a reaction of [Mo(CO)[sub]6.] with Ph[sub]2P(CH[sub]2)[sub]2P(O)Ph[sub]2 (dppeO) which yields a mixture of seven products. It was found that good spectra of pure materials could be obtained TLC separation, followed by removal of the appropriate section silica support from the plate. This was subjected directly to FAB mass spectrometry without prior extraction of the product from silica. Using this technique, it proved possible to identify three new dppeO derivatives of [Mo(CO)[sub]4 (dppeO) derivatives of [Mo(CO)[sub]6. These are [Mo(CO)[sub]5 (dppeO)] cis-[Mo(CO)[sub]4 (dppeO)[sub]2] and [Mo[sub]2(CO)[sub] 4 (dppeO)[sub]2].

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46

Epton, Jeremy W. "Alkene hydroformylation catalysed by dinuclear rhodium complexes." Thesis, Kingston University, 1990. http://eprints.kingston.ac.uk/20536/.

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47

Galeandro-Diamant, Thomas. "Metal nanoparticles as catalysts for alkene hydrosilylation." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1285.

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L'hydrosilylation des alcènes est une méthode cruciale de formation de liaisons carbone-silicium. Elle est utilisée industriellement pour la production de fluides silicones fonctionnels et d'élastomères silicones. Les procédés actuels d'hydrosilylation des alcènes utilisent des complexes de platine comme catalyseurs. Bien que ces complexes soient extrêmement efficients, ils ne sont d'habitude pas récupérés en fin de réaction, ce qui rend leur utilisation coûteuse et peu durable, étant donnée la rareté du platine. Dans ce projet, nous avons synthétisé et testé plusieurs types de nanoparticules métalliques comme catalyseurs pour l'hydrosilylation des alcènes, dans un effort vers des catalyseurs durables. D'abord, nous avons synthétisé des nanoparticules de platine de 2 nm de diamètre et les avons comparées avec le complexe de Karstedt, le catalyseur de référence en hydrosilylation des alcènes. Nous avons montré que les nanoparticules de platine étaient aussi efficientes que le complexe de Karstedt dans des conditions proches des conditions industrielles, malgré leur dispersion métallique plus faible. Ces observations ont réactivé le débat sur la nature réellement homogène ou colloïdale du complexe de Karstedt pendant la catalyse. Ensuite, un catalyseur hétérogène à base de platine, résistant à la lixiviation, a été développé, basé sur l'encapsulation de nanoparticules de platine dans la matrice d'une silice mésostructurée, la SBA-15. Enfin, d'autres catalyseurs alternatifs ont été développés, basés sur d'autres métaux
Alkene hydrosilylation is a crucial method of forming carbon-silicon bonds. It is used industrially for the production of functional silicone fluids and silicone elastomers. The current industrial alkene hydrosilylation processes use platinum complexes as catalysts. Although these complexes are extremely efficient, they are usually not recovered at the end of the synthesis, making their use expensive and unsustainable, given the scarcity of platinum. In this work, we have synthesized and evaluated several kinds of metal nanoparticles as catalysts for alkene hydrosilylation, in a quest towards sustainable catalyts. First, we have synthesized platinum nanoparticles of 2 nm diameter and compared them with Karstedt's complex, the benchmark catatalyst in alkene hydrosilylation. It was shown that platinum nanoparticles were as efficient as Karstedt's complex in industrially relevant hydrosilylation conditions, despite their lower metal dispersion. These findings reactivated the debate on whether's Karstedt's complex was truly homogeneous or colloidal during catalysis. Then, a leaching-resistant heterogeneous platinum catalyst was developed, based on the embedding of platinum nanoparticles in the matrix of a mesostructured silica, SBA-15. Finally, other alternative catalytic systems were developed, based on other metals

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48

Al-araj, Intisar Qahtan Mahmood. "Synthesis of an α-mycolic acid from Mycobacterium brumae containing a cis-alkene and an α-methyl-trans-alkene." Thesis, Bangor University, 2018. https://research.bangor.ac.uk/portal/en/theses/synthesis-of-an-mycolic-acid-from-mycobacterium-brumae-containing-a-cisalkene-and-an-methyltransalkene(9708072e-3643-4fee-b155-46daea099c90).html.

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Mycolic acids are high molecular weight α-alkyl-branched β -hydroxy long chain fatty acids (60-90 carbon atoms). Different species of Mycobacteria may produce different classes of mycolic acids including α-, methoxy and keto mycolic acids, each present as mixtures of homologues. These may also contain different functional groups such as ester, keto, methoxy, hydroxyl, and alkene groups. Mycolic acids and their trehalose esters are very important components of the mycobacterial cell wall. They show very interesting toxic and immunological properties; these offer considerable potential for application in the detection, control, and treatment of mycobacterial infection, and also in developing new methods for the detection of disease. The first part of this project involved the development of a new method for the synthesis of the α- alkyl-β-hydroxy fragment of mycolic acids, which required fewer steps compared to previous syntheses and used L-malic acid as starting material. The second part was to synthesise cis-alkene-α-methyl-trans-alkene mycolic acid (A), which contains a double bond at the distal and proximal positions. This type of mycolic acid has been isolated from Mycobacterium brumae. The third part of the project included the preparation of a number of sugar and glycerol esters of mycolic acid (A). These included the GroMM (B), GMM (C), the arabino-MA fragment from AG (D) and the trehalose esters TDM (E) and TMM (F). The final part of the project involved the synthesis of a different kind of fatty acid: the methyl esters of cyclopropene fatty acids, such as α-methoxy cyclopropane fatty acid (G). These compounds have been tested and were shown to inhibit Toxoplasma gondii growth in vitro, with compound (G) being the most effective.

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49

Hoff, Dietmar. "Effiziente Katalysatoren für die regioselektive Hydroformylierung von Olefinen zu unverzweigten Aldehyden." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=96833914X.

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50

Steinwascher, Jörg. "Photoinduzierte Elektronentransfer-Aktivierung von Azidanionen in Gegenwart von Alkenen und molekularem Sauerstoff Synthese von [beta]-Azidohydroperoxiden [Beta-Azidohydroperoxiden] /." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=960358404.

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Dissertations / Theses on the topic 'Alkemy'

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