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Group 11 'ate bases : towards an understanding of solid- and solution-state structuresPeel, Andrew James January 2017 (has links)
Lithium bis(amido)cuprates are an important class of bimetallic base, which can chemo- and regioselectively metalate aromatic compounds, via directed ortho cupration (DoCu). This thesis begins with an introduction to aspects of the chemistry of organolithium compounds, group 11 organometallic compounds and their lithium 'ate complexes. Examples of such synergic bases are presented and the introduction is concluded with a discussion of lithium bis(amido)cuprate bases, which along with their silver congeners, are the subject of this dissertation. In general, syntheses involve the addition of a lithium amide to a group 11 salt, resulting in the formation of a lithium bis(amido)cuprate or argentate. Structurally focussed work commences with the use of new amide ligands to develop heteroleptic bis(amido)cuprate systems. The reaction of mixtures of lithium amides with CuBr provides a series of novel Lipshutz-type and Gilman cuprates. Interesting structural features are uncovered, which are rationalised in terms of altered steric demands in the newly introduced amide ligands in these systems. CuSCN and CuOCN are investigated as inexpensive and safer alternatives to CuCN in cuprate formation. In the solid state, a series of Lipshutz-type cuprates (TMP)2Cu(SCN)Li2(L) (L = Et2O, THF, THP) are revealed, whose molecular conformations are infuenced by the identity of the Lewis base. However, in benzene solution, in situ conversion of Lipshutz-type to Gilman cuprate is found to occur. Moving to the synthetic setting, derivatisation of chloropyridines is attempted and gives functionalised halopyridines in 51-71 % yield. CuOCN is found to behave quite differently when reacted in the same way as CuSCN, whereby X-ray crystallography reveals structures in which Cu-Li substitution is apparent. The unique reactivity of CuOCN is interpreted with the aid of multinuclear NMR spectroscopy. A new route to Lipshutz-type cuprates is explored by the synthesis of (TMP)2Cu(OCN)Li2(THF) from Gilman cuprate and LiOCN. This avoids Cu-Li substitution. Meanwhile, reaction of lithium N,N-diisopropylamide with CuOCN also avoids metal disorder, to give a novel lithium cuprate-lithium amide adduct. Further advances in our understanding of group 11 'ate complexes are made by introducing silver as a spectroscopically active nucleus in the lithium argentates (TMP)2AgLi and (TMP)2Ag(CN)Li2(THF). In the solid state, these parallel the structures known for Gilman cuprate (TMP)2CuLi and Lipshutz cuprate (TMP)2Cu(CN)Li2(THF), respectively. In solution, NMR spectroscopy reveals features consistent with retention of these structures. Lastly, the formation of mixed Cu-Li aggregates from combining TMPLi and TMPCu in aromatic solvent are investigated. Surprising reactivity is uncovered, in which the aromatic solvent is metalated and incorporated into mixed-metal aggregates. This thesis concludes with a summary of the findings and suggestions for future work, including how the findings presented herein may be transformed into practical improvements to cuprate systems. In particular, the possibility that Gilman cuprate may be activated towards the metalation of aromatic substrates by the addition of sub-stoichiometric or catalytic amounts of a lithium salt additive is explored.
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Den (o)hälsosamma strävan efter det rätta : En kvantitativ studie om orthorexia nervosa & träningsberoendeBlommegård, Erik January 2019 (has links)
Bakgrund: 1997 introducerade den amerikanske läkaren och psykologen Steven Bratman Orthorexia Nervosa (ON), vilket är en relativt ny form av ätstörningsbeteende som kretsar kring en ohälsosam fixering kring hälsosam mat och naturlig föda. Sedermera har ON övergått till att gestaltas som ett fenomen istället för ett begrepp, där träningsberoende (EA) kommit att utgöra ett påtagligt segment i fundamentet och definitionen av Orthorexia Nervosa. Syfte: Undersöka prevalens, ålders- respektive könsskillnader samt korrelationen mellan ON och EA hos deltagare som frekvent tränar på gym. Metod: Kvantitativ tvärsnittsundersökningen. En enkät, med EAI & ORTHO-15 som tillhörande mätinstrument, användes i studiedesignen. Datainsamlingen ägde rum hos tre separata gym vid fem tillfällen under en veckas tid. Totalt medverkade 112 deltagare i studien: 49 män (44 %) och 63 kvinnor (56 %) i åldrarna 18 - 79 år. Resultat: Åtta deltagare (7 %) låg inom riskzonerna för EA samtidigt som 44 (39 %) deltagare låg inom riskzonen för ON. Ålder spelar en påtaglig faktor gällande förhållningssättet till kosten, då det förekommer skillnader mellan olika åldersgrupper: gruppen Under 30 år visar i synnerhet högre andelar för ON (p= 0.005). Det råder en negativ korrelation (– 34 %) mellan mätinstrumenten EAI och ORTHO-15, vilket symboliserar ett destruktivt attribut gällande hälsan. Konklusion: Föreliggande studie ligger i linje med tidigare forskningsresultat inom samma område; det tycks finnas ett samband mellan mätinstrument gällande förhållningssättet till kosten och träningen, vilket mynnar ut i en ohälsosam strävan efter en perfekt hälsa.
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Reinventing Aromatic Substitution: A Novel LookNguyen, Quang 01 August 2013 (has links)
Electrophilic aromatic substitution (EAS) and directed ortho-metalation (DoM) involve the direct substitution of an arene hydrogen. A major drawback involving EAS is the necessity for harsh forcing conditions for the reaction to proceed. Catalysts such as Lewis acids FeBr3 and AICI3 for the introduction of halogens and acyl groups, respectively, are each highly toxic and corrosive. Textbook preparations of aryl iodides classicaly involved the use of iodine and nitric acid. This approach affords only modest yields and does not provide regiospecific substitution of most substituted aromatics because most contain ortho/para directors which afford mixtures of isomers. The novelty of our procedure for the synthesis of the iodinated aromatics is twofold in that regiospecific para-iodination is observed and hydrocarbon media are utilized. Hydrocarbon media are less hazardous and greener than media used for halogenations reported in literature. This procedure always yields derivatives regiospecifically substituted para to an electron donating substituent. Moreover, this method eliminates the need to use hazardous oxidative catalysts. DoM is a reaction regiospecifically substitute an arene hydrogen at the ortho position. The media used in DoM reactions are less hazardous than those required for a variety of EAS reactions. The only problem for this reaction is use of extremely strong bases, alkyllithium reagents, which are known to be air and water sensitive. However, the DoM reaction does eliminate the need to separate ortho/para isomer mixtures so that only a single product is generated. The metalation yields predominantly products regiospecifically substituted ortho-to the direcing metalating group (DMG). With our deficiency catalysis concept and subsequent purificaion methods, relatively pure ortho-lithiated intermediates have been prepared. The study of catalysts/promoters on the derivatization of these intermediates is anticipated to be extremely insightful. For this study, we have shown that highly selective, efficient ortho-lithiation can be achieved by deficiency catalysis utilizing n-BuLi as the only strong metalating base.
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Syntheses and Complexation of {(o-PPh2C6H4)CH=NCH2CH2}3N with Chromium Group Metal CarbonylsHsiao, Shu-Ching 04 August 2004 (has links)
none
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(£¸)Pyrolytic and Photolytic Studies of 2-Methoxy-2¡¦-methylthiostilbene and 2,2¡¦-Di(methylthio)stilbene (¤G) Pyrolytic Study of 2-Dimethylamino-N-(arenylidene)anilines (¤T) Pyrolytic Study of Benzoic 1,2-Dimethyl-3-indolyl AnhydrideJian, Wen-wei 27 July 2009 (has links)
£¸¡B Pyrolysis of 2-methoxy-2¡¦-methylthiostilbene (22a) and 2,2¡¦-di(methylthio)stilbene (22b) gave not only polycyclic aromatic hydrocarbons (PAH) 17¡B18¡B2, but also the products 33, 34. In addition, photolysis of 22a¡B22b¡B2,2¡¦-dimethoxy stilbene (13) gave photocyclic products 31¡B40¡B12¡B45¡B46.
¤G¡B Pyrolysis of 2-dimethylamino-N-(arenylidene)anilines (20a-f) gave not only 1-methyl-2-arylbenzimidazole (25a-f), but also gave 2-arylquinoxaline (26a-e). Furthermore, compound 20f gave 37 and 25f, but didn't give 26f.
¤T¡B Pyrolysis of benzoic 1,2-dimethyl-3-indolyl anhydride gave 1,2-dimethylindole (19) ¡B3-methylquinoline (30) ¡B4-methylquinoline (31).
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Modeling and Parameter Study of Bistable Spherical Compliant MechanismsSmith, Chester 01 January 2011 (has links)
The bistable spherical compliant mechanism (BSCM) is a novel device capable of large, repeatable, out-of-plane motion, characteristics that are somewhat difficult to achieve with surface micromachined microelectromechanical systems. An improved pseudo-rigid-body model (PRBM) to predict the behavior of the BSCM is presented. The new model was used to analyze seven different versions of the device, each with a different compliant joint length. The new model, which adds torsion, is compared with a finite element analysis (FEA) beam model. The new model more closely approximates the results yielded by FEA than previous models used to analyze the BSCM. Future work is needed to quantify stress-stiffening interactions between bending and torsion. Both FEA and the current models show that increasing the length of the compliant segment decreases the amount of force required to actuate the device.
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Approximate quantum dynamics methods for time correlation functionsSmith, Kyle Kurt Gabriel 03 July 2014 (has links)
The dynamic structure factor of liquid para-hydrogen and ortho-deuterium in corresponding thermodynamic states, (T = 20.0 K, n = 21.24 nm⁻³) and (T = 23.0 K, n = 24.61 nm⁻³) respectively, has been computed by both the Feynman-Kleinert linearized path-integral (FK-LPI) and Ring-Polymer Molecular Dynamics (RPMD) methods and compared with Inelastic X-ray Scattering spectra. The combined use of computational and experimental methods enables a reduction in experimental uncertainties for the determination of the true sample spectrum. Furthermore, the refined experimental spectrum of para-hydrogen and ortho-deuterium is consistently reproduced by both FK-LPI and RPMD at momentum transfers lower than 12.8nm⁻¹. At larger momentum transfers the F K - LP I results agree with experiment much better for ortho-deuterium than for para-hydrogen. More specifically we found that for k ~ 20.0 nm⁻¹ para-hydrogen provides a test case for improved approximations to quantum dynamics. We meet this demand for an improved approximate quantum dynamics method by developing two classes of quasi-classical dynamics that are shown to conserve the initial quantum ensemble when used in conjunction with the Feynman-Kleinert approximation of the density operator. As shown, both classes of dynamics are able to recover the exact classical and high temperature limits of the quantum time correlation function, while a subset is able to recover the exact harmonic limit. A comparison of the approximate quantum time correlation functions obtained from both classes of dynamics are made with the exact results for the challenging model problems of the quartic and double-well potentials. It is found that this new Feynman-Kleinert Quasi-Classical Wigner (FK-QCW) method provides a great improvement over the Feynman-Kleinert implementation of the classical Wigner approximation, also known as FK-LPI, in which purely classical dynamics are used. Furthermore, it is shown that the first class of dynamics reduces to Centroid Molecular Dynamics (CMD) when used within the framework of the classical Wigner approximation for the Kubo transformed time correlation function. Finally, we apply the Feynman-Kleinert Quasi-Classical Wigner (FK- QCW) method to the same liquid para-hydrogen and ortho-deuterium system, previously studied using FK-LPI and RPMD. When applied to this challenging system, it is shown that this new FK-QCW method consistently reproduces the experimental dynamic structure factor for all momentum transfers considered. This shows that FK-QCW provides a great improvement over FK-LPI for not only model problems, but also realistic systems. Furthermore, for small momentum transfers, where RPMD is applicable, it is shown that FK-QCW provides nearly the same results as RPMD, thus suggesting that FK-QCW provides a potentially more appealing algorithm than RPMD since one is not limited to correlation functions involving linear operators. This then suggests that the FK-QCW method is a top contender in the realm of approximate quantum dynamics methods which allow for the practical evaluation of time correlation functions. / text
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Neįgalių asmenų, su lėtiniais nugaros smegenų pakenkimais, kvėpavimo funkcijos mechanizmų pokyčiai orto-klinostazės poveikyje / Changes of respiratory function mechanisms of disable people with spinal cord injuries in the influence of ortho-clinostatic stressStanevičiūtė, Simona 18 June 2008 (has links)
Tyrimo naujumas ir aktualumas:
Atlikta mokslinių tyrimų analizė rodo, kad kvėpavimo sistemos reguliacijos pokyčių asmenims, su lėtiniais nugaros smegenų pažeidimais (LNSP) tyrimai išlieka aktualūs iki šiol. Kol kas nėra pilnai aišku, kaip kvėpavimo funkcijos mechanizmai, tarpšonkaulinių įkvėpimo ir iš kvėpimo raumenų bei diafragmos veikla, o taip pat bronchų spindis kinta ir sąveikauja tarpusavyje, priklausomai nuo nugaros smegenų įvairaus lygmens pažeidimo poveikyje atsiradusių krūtinės ląstos ir pilvo raumenų paralyžiaus, nes kompleksinių tyrimų nebuvo atlikta. Taip pat neaišku, kaip šie mechanizmai kinta, ar jų pokytis gali limituoti kvėpavimo funkciją keičiant kūno padėtį, ypač į ortostatinę, kas būtų labai svarbu nustatyti siekiant tyrimo duomenis pritaikyti neįgaliųjų sporto medicinoje.
Literatūros duomenys rodo, kad asmenims su LNSP (lėtiniais nugaros smegenų pažeidimais) kvėpavimo funkcija silpnėja, lyginant su įgaliais asmenimis, kad ji gali priklausyti nuo nefiziologinės diafragmos padėties, susidariusios dėl šonkaulių kampo pokyčių, esant pilvo raumenų paralyžiui, kad esant LNSP gali keistis kvėpavimo takų spindis, kaip konpensacinis mechanizmas sumažėjus išorinio kvėpavimo funkcijai (Alvarez et al, 1981; Baydur et al, 2001; Mueller et al, 2006). Tačiau tokių tyrimų buvo atlikta labai nedaug, ir, kaip jau minėta, kompleksinių tyrimų, apjungiančių šiuos mechanizmus, iš viso neradome. Kvėpavimo funkcijos tyrimai įvairiose kūno padėtyse (gulint, ortostatinėje ir... [toliau žr. visą tekstą] / The novelty of the research:
The investigations show that analyses of the respiratory changes of people with spinal cord injuries are still relevant. However, it is still unknown how pathological mechanisms interact with each other depending to the level of spinal cord injury because no complex investigations were carried out. Also, it is unknown how these mechanisms vary depending on the body position. Whether they limit the physical activity in the sport of disable people in order to prevent complications in the respiratory system or whether physical activities can reduce the influence of the pathological mechanisms to the respiratory system in this way improve it. These questions are very important in the medicine of the disable sport. Such investigations are not carried out with the people with spinal cord injuries.
Previous researches show that peope with spinal cord injuries have weal respiratory function comparing with able people (Mueller et al, 2006). It can be depended on the non physiological position of the diaphragm which is formed due to the changes of the rib angle with paralysis of the abdomen muscle. Also, in the condition with spinal cord injuries the transience of the airways can be changed as compensation mechanism for the reduced function of the external respiratory. However, there are very few researches carried out and as it was mentioned previously, no integrated researches were carried out which involve these mechanisms. The analysis of the... [to full text]
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Synthetic Methods and Application Based on Directed ortho Metalation and Suzuki Cross Coupling StrategiesAlessi, MANLIO 17 December 2008 (has links)
The Directed ortho Metalation reaction is described in Chapter 1 of this thesis with particular emphasis on its mechanism and synthetic potential. Chapter 2 contains a review of the DoM (Directed ortho Metalation) of pyridine systems and describes the conditions that allow the one-pot DoM (Directed ortho-Metalation)-Boronation-Suzuki-Miyaura cross coupling of pyridines 2.263a-c, 2.351-2.53 (Table 2.9) bearing several DMGs (Directed Metalation Groups) including the synthetically versatile diethyl amide functionality without incurring into commonly observed self-condensation processes. The method avoids the tedious and uncertain isolation of the intermediate boronic acids while offering rapid access to synthetically valuable arylpyridines (2.354a-s, Table 2.9). Selected aryl pyridine carboxamides were used to demonstrate the DoM-DreM (Directed remote Metalation) nexus that furnishes substituted and isomerically diverse azafluorenones 2.380a-d (Table 2.11) with high regioselectivity.
The previous discovery of the anionic O→C -vinyl carbamoyl migration of carbamoyl stilbenes stimulated its application in the total synthesis of natural product isoprekinamycin, bearing the unusual diazo group. Chapter 3 of this thesis describes the efficient synthesis of the key stilbene derivative 3.113 and its structural variations whose conversion to the desired naphthols 3.143, 3.144, 3.153 and 3.169 (Table 3.3) is accompanied by extensive decomposition, thus terminating this approach to isoprekinamycin. A modified approach via Z-3.271 (Scheme 3.54) gave the desired naphthyl carbamate intermediates 3.274 and 3.278 (Schemes 3.55 and 3.56, respectively) whose complex DreM reactions prevented the completion of the synthesis but remain under active investigation in our laboratories.
Previous studies of the DoM reaction of aryl tetramethyl phosphorodiamidate have shown that unpractical experimental conditions are necessary, thus limiting synthetic application. Chapter 4 of this thesis describes the results concerning the performance of the tetraethyl phosphorodiamidate DMG under standard DoM and DreM conditions, anionic phospha-Fries rearrangement, 1,4 lateral migration, and Suzuki cross coupling which demonstrate synthetic utility and application in synthetic aromatic chemistry. / Thesis (Ph.D, Chemistry) -- Queen's University, 2008-12-16 14:15:09.695
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The Synthesis of Novel and Sterically Demanding Tetra-ortho-substituted Aryl NaphthalenesGlass, Adam Cameron, 1983- 09 1900 (has links)
xiv, 326 p. : ill. (some col.) / Tetra-ortho -substituted aryl naphthalenes (TOANs) are a motif of great importance, being present in biologically active natural products, chiral ligands, and building blocks relevant to materials science. The synthesis of sterically demanding and enantioenriched TOANs continues to be a challenge for current synthetic methods.
Herein, we describe the highly effective synthesis of a variety of sterically demanding and enantioenriched TOANs through a rearrangement-based method. Our method utilizes a cyclopropyl carbinol moiety as the key rearrangement precursor. We have demonstrated that carbon-carbon coupling through a simple nucleophilic attack on a cyclopropyl indanone allows for very large aryl substrates to be added and rearranged. We discuss in detail the following: 1) the initial substrate-scope and proof-of-concept studies, 2) our progress in building the most sterically demanding TOANs to date, and 3) the asymmetric synthesis of TOANs through chiral transfer.
This dissertation includes previously published and unpublished co-authored material. / Committee in charge: Michael M. Haley, Chairperson;
Shih-Yuan Liu, Advisor;
Darren W. Johnson, Member;
Victoria J. DeRose, Member;
Paul J. Wallace, Outside Member
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