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1
Braddock, D. C. "Towards an asymmetric ene reaction." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307037.
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Ahmed, Ghafoor. "Novel transition metal catalysts for intramolecular ene-reaction." Thesis, University of Leicester, 1997. http://hdl.handle.net/2381/29970.
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We have designed a new class of MII-catalysts, namely molybdenum and tungsten (II) complexes of the type PhCH2(Et)3N+[M(CO)4C1Br2]- and M(CO)5(OTf)2 (M = Mo or W), which induce intramolecular cyclization of olefinic aldehydes to afford products with a cis-configuration at the newly formed chiral centres in some cases. These catalysts can be tuned to drive the reaction either toward the end or Prins-type product (32 or 89). The latter reaction occurs via an anti addition of the carbonyl carbon and OH across the C=C bond, as evidenced by isotopic labeling. A chair-like transition state with an axial carbonyl oxygen is proposed to rationalise the stereoselectivities observed.
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Thompson, Michael Richard. "Maleation of polypropylene and EPDM through reactive extrusion using the Alder Ene reaction." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0024/NQ30654.pdf.
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Dogan, Sengul Dilem. "Regioselectivity In The Ene Reaction Of Singlet Oxygen With Cyclic Alkenes And Application Of Ene Reaction To Stereoselective Synthesis Of Carbaheptopyranose Derivatives." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612648/index.pdf.
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In the first part of this thesis is related to the regioselectivity in ene reaction of singlet oxygen with cyclic alkenes. The photooxygenation of 1-methyl-, 2,3-dimethyl-, 1,4-dimethylcyclohexa-1,4-dienes, 1,2,3,4,5,8-hexahydronaphthalene (16) and 2,3,4,7-tetrahydro-1H-indene (17) which are readily available through Birch reduction, yielded the ene products. The formed endocyclic dienes were trapped by the addition of singlet oxygen to give corresponding bicyclic endoperoxy-hydroperoxides. In the case of 1-methylcyclohexa-1,4-diene (13) and 1,4-dimethyl-cyclohexa-1,4-diene (15), cis-effect determined the product distribution. Photooxygenation of 2,3-dimethylcyclohexa-1,4-dienes (14) gave mainly exocyclic olefin, which was attributed to the lowered rotational barrier of the methyl group and increased reactivity of the methyl groups. Photooxygeneation of 1,2,3,4,5,8-hexahydronaphthalene (16) and 2,3,4,7-tetrahydro-1H-indene (17) shows importance of the geometry of the allylic hydrogen in the ground state.
In the second part of this thesis is related to the stereoselective synthesis of carbaheptopyranose derivatives. Two new carbaheptopyranoses, 5a-carba-6-deoxy-&alpha-DL-galacto-heptopyranose (184) and 5a-carba-6-deoxy-&alpha
-DL-gulo-heptopyranose (185) have been prepared starting from cyclohexa-1,4-diene. The addition of dichloroketene to cyclohexa-1,4-diene followed by subsequent reductive elimination and Baeyer-Villiger oxidation formed the bicyclic lactone 188. Reduction of the lactone moiety followed by acetylation gave the diacetate 182b with cis-configuration. Introduction of additional acetate functionality into the molecule was achieved by singlet oxygen ene-reaction. The formed hydroperoxide 189 was reduced and then acetylated. The double bond in triacetate was further functionalized either by direct cis-hydroxylation using OsO4 or epoxidation followed by ring-opening reaction to give the hepto-pyranose derivatives 184 and 185.
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Idris, M. S. H. "A study of the ene reactions of 1,2,3-tricarbonyl systems." Thesis, University of Nottingham, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353550.
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Sobanska, Anna W. "Application of the glyoxlate ene reaction to natural product synthesis." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670260.
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Atkinson, Duncan. "Novel methods for allylic amination by an intramolecular nitroso ene reaction." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/14069.
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C-H functionalisation reactions aim for the selective cleavage of C-H bonds, and formation of a new carbon or heteroatom bond, often with the use of a transition metal catalyst. These reactions offer potential for functionalisation of hydrocarbons in fewer steps than conventional methods, and with high atom efficiency. They are therefore a subject of intense research in organic synthesis. Carbon-heteroatom bond forming reactions are particularly sought after, and useful in the efficient synthesis of many biologically significant groups such as oxazolidinone rings, 1,2 or 1,3 amino alcohols and amino acid analogues. An efficient, cheap and robust method for C-H amination would also be adaptable to varied syntheses of important large molecules. The necessity for complex and efficient transformations with a minimal number of steps means that heteroatom ring closures are also attractive and widely used reactions in such large molecule syntheses. The nitroso group is a highly reactive species which is normally generated in situ by oxidation of a hydroxylamine, for carbon-nitrogen bond forming reactions including the nitroso Heteroatomic Diels Alder reaction, nitroso ene reaction, and nitroso aldol reaction. Nitroso group reactions often show high stereo- and regioselectivity, and have formed key components of the syntheses of important biological molecules. Enantioselectivive protocols for the nitroso-ene reaction and, to a lesser extent, the nitroso HDA reaction, are poorly developed, however, and the range of available intramolecular nitroso reactions is limited. We aimed to establish efficient single-step intermolecular C-H amination reactions, to give 1,2 and 1,3 heteroatom functionalised molecules, and to develop the capacity for enantioselective induction in this reaction, if possible. Having synthesised a model set of unsaturated hydroxycarbamates, we identified a suitable system for nitroso generation, using a catalytic metal and stoichiometric oxidant. This resulted in in situ generation of cyclised product, with the olefin functionality intact. This cyclisation was then optimised and used to obtain a range of new heterocycles. The possibility of enantioselective induction via chiral catalysts was explored, as well as catalytic systems to increase the stereoselectivity of the reaction. In summary, a cheap, novel and reliable method was developed for formation of oxazolidinone rings from unsaturated hydroxycarbamates using an original intramolecular nitroso ene reaction, and a range of unsaturated heterocycles were synthesised in fairly good yields. Distereoselectivity of the nitroso ene cyclisations was optimised. However, to-date, we were unable to develop an enantioselective varient of the reaction. Several related aminations, as well as transformations of N-hydroxyoxazolidinone products, were also attempted during the project.
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Marcotte, Joel. "Formal Synthesis of (+/-) Morphine via an Oxy-cope/Claisen/Ene Reaction Cascade." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23560.
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For years now, opium alkaloids and morphinans have been attractive synthetic targets for numerous organic chemists due to their important biological activity and interesting molecular architecture. Morphine is one of the most potent analgesic drugs used to alleviate severe pain. Our research group maintains a longstanding interest in tandem pericyclic reactions such as the oxy-Cope/Claisen/ene reaction cascade and their application to the total synthesis of complex natural products. Herein we report the ventures towards the formal synthesis of (+/-)-morphine based on the novel tandem oxy- Cope/Claisen/ene reaction developed in our laboratory. These three highly stereoselective pericyclic reactions occurring in a domino fashion generate the morphinan core structure after only 7 steps from commercially available material. The formal synthesis culminated in the production of a formal intermediate after a total of 18 linear steps, with an overall yield of 1.0%, successfully intersecting two previous syntheses of the alkaloids, namely the ones of Taber (2002) and Magnus (2009).
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Liu, Xingguo, and 刘兴国. "Concise synthesis of racemic and chiral fumagillol via intramolecular carbonyl ene reaction." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46588292.
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Abu, Ajaj Khalid. "Synthesis of Phosphonate Analogues of the Antibiotic Moenomycin A12." Doctoral thesis, Universitätsbibliothek Leipzig, 2004. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-37333.
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SUMMARY The moenomycin-type compounds are known to inhibit selectively the enzyme penicillin binding protein 1b (PBP 1b) that catalyses the transglycosylation reaction in the biosynthesis of bacterial cell wall peptidoglycan. The moenomycins (see moenomycin A12) have been shown to interfere with this biosynthetic step interacting with the enzyme(s). The moenomycins do not induce resistance readily. A weak point in this respect may, however, be the phosphate bond to unit F. Its cleavage by a yet poorly characterized enzyme is the only enzymatic degradation reaction of the moenomycins that is known to-date. With this in mind we started a programme aimed at synthesizing trisaccharide analogues of moenomycin A12 in which the phosphate oxygen at C-1 of unit F is replaced by a CH2 group. It seemed important to retain all other functional groups in ring F as present in moenomycin since they are known to be of major importance as far as antibiotic activity is concerned. It appeared that the commercially available and cheap b-D-galactose-pentaacetate 30 would be an interesting starting material for this synthesis. In this work, the synthesis began with the introduction of the C-glycoside appendage at position 1 according to Giannis et al., thus forming the allyl C-galactopyranoside 34, a substance that represents the first C-glycosyl backbone for the synthesis of the glycosyl acceptors. The total synthesis of the glycosyl acceptors is shown in Scheme 6.1. We wanted to convert the C-allyl glycoside 34 into its propenyl analogue. Attempts to achieve this with singlet oxygen and palladium-mediated reaction proved fruitless. On the other hand, ene reaction of 34 with 4-phenyltriazolin-3,5-dione in CH2Cl2 provided 56 in 83 % yield. Ozonolysis of this alkene (-70 °C, MeOH-CH2Cl2) and subsequent quenching with dimethyl sulfide, followed by reduction of the crude aldehyde with sodium acetoxyborohydride (prepared from NaBH4 and AcOH in THF) furnished the primary alcohol 35 (85 %). This alcohol was converted into the mesylate 60 (60 %), and this in turn into the bromide 61 (80 %) by heating it at 80 °C with tetrabutylammonium bromide in toluene. The acetate groups were hydrolysed using Zemplén conditions to furnish 62 quantitatively. The primary hydroxyl group in 62 was protected as a tBuPh2Si ether 63 (85 %) on reaction with TBDPSCl in DMF at 0 °C, and as a tBuMe2Si ether 94 (87 %) on reaction with TBDMSCl in DMF at 0 °C in the presence of imidazole. PTScatalysed isopropylidenation of the 3,4-diols 63 and 94 with 2,2-dimethoxypropane in dry acetone gave the 3,4-O-acetonide derivatives 53 (88 %) and 95 (90 %), respectively. On the other hand, the glycosyl acceptor 53 was converted into the glycosyl acceptor 92. The free hydroxyl group in compound 53 was protected as an acetate group on reaction with acetic anhydride in pyridine in the presence of DMAP giving 89 (88 %). The silyl ether in 89 was cleaved with a molar solution of TBAF in THF affording compound 90 in 87 % yield. The free hydroxyl group in 90 was then subjected to an oxidation using the TEMPO method affording the aldehyde which was in turn oxidised with sodium chlorite to the corresponding acid. The acid was converted to the amide 91, making use of Staab's method, in which the acid was activated with CDI in dichloromethane to give the imidazolide, which upon reaction with ammonia furnished the amide 91 in an overall yield of 95 %. The required glycosyl acceptor 92 was obtained in quantitative yield by cleavage of the ester bond at position 5 under Zemplén conditions. Disaccharide formation was achieved employing the Jacquinet and Blatter method, which involves the use of glycosyl donor 67 and TMSOTf. No reaction was observed between this donor and acceptor 92, which may reflect the low nucleophilicity of the acceptor. On the contrary, glycosylation with acceptor 53 gave 68 (79 %). Deprotection of the silyl group in the disaccharide 68 was easily accomplished on treatment with a molar solution of TBAF in THF at RT affording 71 (89 %). Synthesis of the uronamide 72 was achieved after three major steps, in an overall yield of 98 %. Oxidation of the primary hydroxyl group in unit F to the corresponding aldehyde was accomplished with sodium hypochlorite and TEMPO. Oxidation of the crude aldehyde to the carboxylic acid with sodium chlorite followed by amide formation according to Staab gave 72. Removal of the isopropylidene group from 72 with trifluoroacetic acid (TFA) at RT furnished the diol 73 (89 %). Introduction of the carbamoyl group at C-4F position was achieved in two steps. Conversion of the diol 73 into the cyclic carbonate 76 with CDI in CH2Cl2 (84 %) and subsequent ring opening of this carbonate by bubbling a stream of gaseous ammonia into the CH2Cl2 solution at 0 °C gave 74 (62 %) as well as its isomer 77 (21 %). Dehalogenation of the N-trichloroacetyl group was intensively studied, but interactions of other functional groups in the studied substances could not be avoided. The base-labile carbonate in 76 and the carbamoyl group in urethane 74 were cleaved under the reaction conditions. Hydrolysis of 76 with 0.5 M LiOH in MeOH-THF (1:1) followed by acetylation gave 80 (73 %), while its reduction with NaBH4 in ethanol followed by acetylation gave 82 (60 °C, 85 %; RT, 83 %). On the other hand, reduction of 74 with NaBH4 in ethanol at 60 °C followed by acetylation gave 82 (78 %), while performing the reduction step at 5 °C (THF-MeOH 4:1) or at RT (ethanol or isopropanol) gave 80 in an average yield of 65 %. In a non reproducible reaction (NaBH4, EtOH, RT, then Ac2O, pyridine, RT), the desired compound 83 (42 %) was obtained accompanied by 82 (46 %) The reaction between the N-trichloroacetyl group and NaBH3CN was also fruitless. The phosphonate grouping was installed making use of Arbuzov reaction furnishing 85 (70 %). Trisaccharides could not be obtained from the oxazoline donor 42 (prepared from chitobiose octaacetate 86) through its reaction with acceptor 53. There was also no coupling product between the recently synthesized donor 88 and the acceptor 92. However, in this work, trisaccharide formation was achieved through the glycosylation reaction of donor 88 and acceptor 95 in 50 % yield (-30 °C, 1,2-dichloroethane, 3 Å, TMSOTf-TEA). Selective deprotection of the TBDMS group in compound 96 was accomplished at -10 °C with 1 eq of a molar solution of TBAF in THF. The free hydroxyl group of 97 was subjected to an oxidation using the TEMPO method affording the aldehyde. After oxidation of the aldehyde with sodium chlorite, the resulting carboxylic acid was converted according to Staab's method into the amide 93 in an overall yield of 95 % (based on 96). There were difficulties in converting the N-phthalimido group in 93 to the N-acetyl group which is necessary for biological activity of moenomycin-type compounds, since the reactions were accompanied by elimination of HBr. In conclusion, the synthetic methods employed in this work allow to prepare the di- and trisaccharides C-phosphonate analogues of moenomycin A12Synthese von Phosphonat-Analoga des Antibiotikums Moenomycin A12 Universität Leipzig, Dissertation Diese Arbeit enthält 130 Seiten, 73 Abbildungen, 1 Tabelle, 156 Literaturangaben Referat: Im Rahmen der vorliegenden Arbeit wurden C-Glycosid-Di- und Trisaccharid-Bausteine des Antibiotikums Moenomycin A12 ausgehend von b-D-Galactose-pentaacetat hergestellt. Das Ausgangmaterial wurde in D-Galactoheptonamid übergeführt. Die Einheit F des Disaccharidbausteins hat alle Substituenten, die die Einheit F des Moenomycins A12 hat. Der ausgearbeitete Syntheseweg sollte zur Synthese anderer Analoga geeignet sein
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Eberlin, Ludovic. "Novel applications of polyfunctionalised organoboron and nitroso compounds." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S078/document.
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Cette thèse présente la réactivité de diènes polyfonctionnalisés incorporant un atome de bore (diènes borylés) en présence de composés de type nitroso. La première partie est une étude de la réactivité des diènes borylés en présence de dérivés arylnitroso. Le produit formé ainsi que l'efficacité de la réaction est dépendant de la substitution sur l'atome de bore ainsi que du solvant utilisé pour la réaction. Suivant les conditions employées, la formation de composés avec différentes structures; pyrroles, oxazines substitués par un atome de bore, ou nitrones a été obtenue. Une stratégie one-pot a ensuite été développée pour la synthèse d'oxazolines utilisant la formation des nitrones en tant qu'intermédiaire. Des investigations théoriques et pratiques concernant le mécanisme de la formation du pyrrole ont été réalisées. La séquence expliquant la synthèse de cette structure est basée sur la cascade suivante; cycloaddition régiosélective (Nitroso Diels-Alder)/réarrangement/élimination du borate. La formation des composés de type nitrone n'a pas été totalement explicité. Des recherches sont actuellement en cours dans le but d'obtenir plus de détails sur le mécanisme mis en jeu. La deuxième partie de l'étude est orientée sur la réactivité des diènes borylés en présence de dérivés carbonylnitroso. Au contraire des dérivés arylnitroso, la nature du composé carbonylnitroso joue un rôle majeur sur la réactivité. Si le même type de réactivité engendrant la formation de pyrroles et d'oxazines substitués par un atome de bore a été observé dans certains cas, l'utilisation d'un composé carbonylnitroso étant assez pauvre en électrons génère la formation du produit issu d'une réaction nitroso-ène. Ce produit, issu de la réaction nitrosoène, a été utilisé comme intermédiaire clé pour la synthèse de différents produits polycycliques. Une séquence one-pot, multicomposants, Diels-Alder/allylboration a été optimisée donnant différentes structures suivant le dienophile et l'aldehyde employé. Dans le but de diversifier la chimie du produit résultant de la réaction nitroso-ène, une autre séquence a été mise au point utilisant la synthèse des pyrroles. Une voie multi-étape a permis la synthèse de nouvelles structures bicycliques incorporant une oxazine et un pyrroleThis thesis presents the reactivity of dienylboronated compounds towards arylnitroso and carbonylnitroso derivatives and its use in the synthesis of heterocyclic and polycyclics compounds. The first study focused on the reactivity of dienylboronate compounds with arylnitroso derivatives resulting in pyrrole or furan products. The outcome and efficiency of the reaction is related to the boron on the dienyl moiety and the solvent used. Using the certain conditions, pyrroles, boronated MIDA ester oxazines or nitrones could be obtained. A one-pot strategy was then applied to synthesise oxazoline derivatives using nitrones as an intermediate. Theoretical, as well as experimental, work has supported that the formation of the pyrrole was obtained by a regioselective nitroso Diels-Alder reaction/rearrangement/borate elimination cascade process. Details on the nitrone formation have not been clarified, but further investigations are on-going. Secondly, attention was focused on the reactivity of dienylboronate compounds with carbonylnitroso derivatives. Contrary to the arylnitroso species, the nature of the carbonylnitroso had a dramatic impact on reactivity. On the one hand, similar reactivity towards the formation of pyrroles and boronated MIDA ester oxazines was observed, however, by employing a higher electron-deficient carbonylnitroso species, the product resulting from a nitroso-ene reaction was obtained. Ene-product was used as the key intermediate for the synthesis of different polycyclic compounds. A multicomponent, one-pot, Diels-Alder/allylboration procedure was optimised to yield various structures depending on the nature of the dienophile and the aldehyde. To diversify the chemistry of the ene-product another sequence was designed using the pyrrole synthesis. A multi-step pathway was optimised to afford novel fused bicylic oxazine-pyrrole products
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Alminderej, Fahad Mohammad. "SYNTHESIS AND CHARACTERIZATION OF POLYURETHANE DENDRIMERS SUBSEQUENT CLICK REACTION." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1469447068.
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Ahuja, Sapna. "Uncovering New Photochemical Pathways Through Molecular Restrictions." Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1594996288079527.
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Marturano, Raffaella. "The kinetics and mechanism of the ene reaction of vinylidene alkenes with maleic anhydride." Thesis, University of Surrey, 2001. http://epubs.surrey.ac.uk/843936/.
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The 'ene' reaction is a pericyclic reaction related to the Diels-Alder reaction. It can be used to synthesise products of commercial importance. An example is its use to attach a 'succinic acid functionality' (via maleic anhydride -MA-), to the ene-terminated polyisobutylene (PIB) to yield PIBSA. While there have been a limited number of studies of the ene reaction, none have concentrated on the reactivity of the vinylidene fragment (CH2-C(=CH2)-CH3) which is found in PIB. In addition there are difficulties in the determination of the kinetics of the PIBSA reaction, because of several competitive processes, which may occur. Therefore the overall aim of the project is to investigate the kinetics and mechanism of the ene reaction between a range of simple vinylidene alkenes (including PIB) and maleic anhydride. A small range of alkenes, 2-methyl-4-phenylbut-1-ene, 2-methyl-4-phenylpent-1-ene, 2.4-dimethyl-4-phenylpent-1-ene and 2,4-dimethyl-4-(-4-fluorophenyl)pent-1-ene, were synthesised, in overall yields of 10 to 35 %. Syntheses were achieved using 1,4-conjugate addition, Friedel-Crafts and Wittig methodologies, and purification involved column chromatography and distillation. Product identification was by 1H NMR and 13C NMR spectroscopy. NMR monitoring of the reaction of 4-phenylbut-1-ene under conditions of equimolar MA in 1,2,4-trichlorobenzene solvent allowed the identification of the adduct 3-(4- phenyl-2-butenyl)dihydro-2,5-furandione as a 9:1 mixture of E and Z isomers. No evidence for further reaction to yield a di-adduct. Similar monitoring of the reactions of the other enes yielded no clear evidence of the adduct. However, under conditions of excess MA, 2,4-dimethyl-4-phenylpent-1-ene, 2.4-dimethyl-4-(-4-fluorophenyl)pent-l-ene yielded the expected adduct. PIB showed evidence of the adduct. A comparison of the 1H-NMR spectra for 2,4-dimethyl-4-phenylpent-1-ene, 2,4-dimethyl-4-(-4-fluorophenyl)pent-1-ene, PIB showed that, in all cases, only product derived from migration of the 1° H was found. Furthermore, no di-adduct was formed even for 2,4-dimethyl-4-phenylpent-1-ene, 2,4-dimethyl-4-(-4-fluorophenyl)pent-1-ene, with large excess of MA. The rate constants in the range 160 °C to 190 °C were determined for all alkenes mostly under conditions of excess MA, but some under conditions of excess alkene. Second order rate constants at 180°C varied from 4*10-5 to 100*10-5 with 4-phenylbut-1-ene being significantly slower than the others. A small medium effect of ca. 2 was identified as resulting from the change from excess ene to excess maleic anhydride. The activation parameters were in the range DeltaH+ 48 to 120 kJ mol-1 and DeltaS+ -53 to -229 J mol K-1. A computational calculation using Hartree-Fock and Semi-Empirical methods of the FMO, HOMOene-LUMOenophile gap allowed ranking of the alkenes. In general the gross trend in reactivity found experimentally was reflected in the computational work. The findings are compared to others and rationalised in terms of a pericyclic, exo Transition State, with the incipient C=C preferring an E configuration.
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Vastesson, Alexander. "Thiol-ene and Thiol-ene-epoxy Based Polymers for Biomedical Microdevices." Doctoral thesis, KTH, Mikro- och nanosystemteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215110.
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Within healthcare there is a market pull for biomedical devices that can rapidly perform laboratory processes, such as diagnostic testing, in a hand-held format. For this reason, biomedical devices must become smaller, more sophisticated, and easier to use for a reasonable cost. However, despite the accelerating academic research on biomedical microdevices, and especially plastic-based microfluidic chips, there is still a gap between the inventions in academia and their benefit to society. To bridge this gap there is a need for new materials which both exhibit similar properties as industrial thermoplastics, and that enable rapid prototyping in academia. In this thesis, thiol-ene and thiol-ene-epoxy thermosets are evaluated both in terms of their suitability for rapid prototyping of biomedical microdevices and their potential for industrial manufacturing of “lab-on-chips”. The first part of the thesis focuses on material development of thiol-ene and thiol-ene-epoxy thermosets. Chemical and mechanical properties are studied, as well as in vitro biocompatibility with cells. The second part of the thesis focuses on microfabrication methods for both thermosets. This includes reaction injection molding, photostructuring, and surface modification. It is demonstrated how thiol-ene and thiol-ene-epoxy both provide advantageous thermo-mechanical properties and versatile surface modifications via “thiol-click chemistry”. In the end of the thesis, two applications for both polymer platforms are demonstrated. Firstly, thiol-ene is used for constructing nanoliter well arrays for liquid storage and on-demand electrochemical release. Secondly, thiol-ene-epoxy is used to enhance the biocompatibility of neural probes by tuning their flexibility. It is concluded that both thiol-ene and thiol-ene-epoxy thermosets exhibit several properties that are highly suitable for rapid prototyping as well as for scalable manufacturing of biomedical microdevices.QC 20171003
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Wutticharoenwong, Kosin. "BIO-BASED REACTIVE DILUENTS AND THIOL-ENE PHOTOPOLYMERIZATION FOR ENVIRONMENTALLY BENIGN COATINGS." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1194282497.
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RENAUD, JEAN-LUC. "Nouveaux developpements de la reaction de conia-ene. Approches au squelette de base des gibbanes." Paris 6, 1998. http://www.theses.fr/1998PA066606.
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Il a ete mis en evidence au laboratoire une nouvelle catalyse par les complexes du cobalt (i) de la reaction de conia-ene mettant en jeu des -cetoesters--ynes et conduisant a des methylenecyclopentanes fonctionnalises. Cette reaction est realisee dans des conditions tres douces au reflux des solvants tels que le tetrahydrofurane, le benzene et les xylenes. Dans le cadre de l'application de cette nouvelle catalyse a la synthese de molecules plus complexes, nous avons etudie la possibilite d'introduire des substituants sur le motif cyclopentanique de facon controlee. Une etude systematique a montre que cette reaction est diastereoselective puisqu'elle permet le controle de la stereochimie relative des centres stereogenes formes en -1,2, en -1,4 avec des exces diastereomeriques moderes a excellents. L'ensemble des resultats observes, notamment ceux concernant la diastereoselection-1,2, nous a conduit a proposer un mecanisme original de cycloisomerisation mettant en jeu un motif enol-yne et transitant via un metallacycle. Cette cycloisomerisation, associee a une reaction de pauson-khand, nous a donne un acces rapide et efficace au triquinane angulaire. Les unites bicycliques 5,5-, 5,6-, 5,7- et 5,8 etant couramment rencontrees dans les structures de base de produits naturels, nous nous sommes interesses a la reactivite de -cetoesters -acetyleniques cycliques en presence des complexes du cobalt(i). Nous avons decouvert que cette reaction de cycloisomerisation permettait un acces rapide, efficace et totalement diastereoselectif a des carbocycles de type n. 3. 0 fonctionnalises. Ayant etabli par les etudes precedentes que la conia-ene reaction catalysee par les complexes du cobalt (i) permettait la synthese hautement diastereoselective a la fois de methylenecyclopentanes et de systemes bicycliques de type n. 3. 0, nous nous sommes proposes d'utiliser cette reaction dans une approche aux squelettes de base des gibbanes. Cette approche serait realisee via une double reaction de conia-ene associee a une cycloaddition 4 + 2. Les differentes strategies sont a l'etude au laboratoire, toutefois nous avons pu montrer que les reaction de diels-alder etaient totalement diastereoselectives.
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Sumoreeah, Ravi Leckman. "Studies towards the total synthesis of galanthamine and the total synthesis of 2-Benzoyl-9-azabicyclo[4.2.1]non-2-ene : phenyl analogue of (#+-#)Anatoxin-a." Thesis, University of Sussex, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289225.
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This thesisd escribess yntheticw ork carriedo ut on two separatep rojects. (i) Synthetics tudiest owardst he total synthesiso f galanthamine (ii) The total synthesis of 2-Benzoyl-9-azabicyclo[4.2.1 ]non-2-ene Galanthamine is an amaryllidaceae alkaloid processing a rigid tetracyclic structure with a fused dihydrobenzofuran onto a cyclohexenol and a bridging tertiary amine. 2-Benzoyl-9-azabicyclo[4.2.1]non-2-ene is an analogue of anatoxin-a, whereby the acetyl side chain has been substituted with a benzoyl group. Anatoxin-a itself possesses a 9-azabicyclo[4.2.1]nonane framework. Although structurally very different they both share a common feature in that they interact with acetylcholine receptors. Hence chapter 1 is an introduction to Alzheimer's disease which is primarily caused by a lack of acetylcholine. A literature review of the total syntheses of galanthamine and a background of galanthamine is described in chapter 2, whilst chapter 3 details the forward synthesis to the galanthamine framework but with a cyclopentenyl instead of a cyclohexenyl moiety and subsequent attempts for the elaboration of the cyclopentenyl into its corresponding cyclohexenyl moiety. Chapter 4 and 5 describes the published total syntheses of anatoxin-a and analogues of anatoxin-a, whilst chapter 6 concludes the total synthesis of the phenyl analogue of anatoxin-a via a key selenium mediated transannular cyclisation of a Boc-(3-Lactam to furnish the 9-azabicyclo[4.2. l]nonane ring system.
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Deon, Daniel. "The effect of DBU on the tandem oxy-Cope/ene reaction and total synthesis of (+)-Arteannuin M." Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/9193.
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Tandem reactions have been proven to be powerful methods for creating new types of carbon-carbon bonds in organic synthesis. One such type of reaction is the oxy-Cope/ene reaction of 1,2-divinylcyclohexanols. This reaction has been shown to be a highly diastereoselective method for creating polycyclic compounds with tertiary alcohols at a ring junction. Unfortunately, in many of the previously reported cases, undesired retroene products were also observed.* A new method has been developed that increases the ratio of oxy-Cope/ene with respect to retroene product that involves the use of DBU as a co-solvent in this reaction. This methodology was applied to intermediate 109 (readily obtainable from (+)-limonene) as a key step in the total synthesis of (+)-Arteannuin M (128), a potential drug for the treatment of malaria.* *Please refer to dissertation for diagrams.
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TESTON-HENRY, MICHELE. "Vers la catalyse de la reaction ene : reactivite des esters et des anhydrides insatures en presence d'acides de lewis." Palaiseau, Ecole polytechnique, 1991. http://www.theses.fr/1991EPXX0028.
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Ce travail porte sur la reaction ene entre le beta-pinene comme compose ene et un ester (acrylate de methyle) ou des anhydrides insatures (maleique et itaconique) comme composes enophiles, catalysee par des acides de lewis. Il s'articule autour de deux axes: 1) l'etude des acides de lewis par rmn (#1h & #1#3c) et par calcul d'orbitales moleculaires (mndo) pour determiner leur force, ainsi que leur mode de complexation avec les enophiles; 2) l'etude experimentale des reactions precedemment citees. Les differences de comportement entre les enophiles se comprennent grace aux outils mis au point dans la premiere partie
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SUN, HUIKAI. "IRON TRICARBONYL PROMOTED CYCLIZATIONS: POTENTIAL APPLICATION TOWARD TOTAL SYNTHESIS OF 18-DEOXYCYTOCHALASIN H." Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1190143838.
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PACIFICO, Salvatore. "Sintesi di glicopeptidi mediante le reazioni tiol-ene/ino e studio della reattività di Umpolung di α-dichetoni." Doctoral thesis, Università degli studi di Ferrara, 2013. http://hdl.handle.net/11392/2388912.
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It is well established that protein glycosylation, a bioorthogonal process, is a posttranslational modification that profoundly affects protein folding, stability, immunogenicity, and biological properties and activities. In this regard, while native O- and N-glycosidic bonds of glycopeptides are prone to hydrolytic cleavage by O- and N-glycosidases, synthetic C- and S-analogs are expected to be stable toward such enzymatic degradation. Therefore, much effort has been devoted in the last decades to synthesizing C- and S-glycosyl amino acids and their assembly in glycopeptides. They with these non-native linkages can be used as probes for biochemical studies and leads in drug discovery, such as, for example, vaccines. In the first part of this thesis project we developed two routes to synthesis of S-glycopeptides. One route consists of S-glycosyl amino acid synthesis from photoinduced addition of sugar thiols to alkenyl glycine (TEC) followed by incorporation of this amino acid into a peptide. The second route, that is, specific for a cysteine containing peptide such as glutathione, involves peptide S-homoallylation followed by TEC with sugar thiol. We also demonstrated the selective propargylation of cysteine-containing peptides followed by photoinduced thiol-yne coupling with glycosyl thiols as an effective one-pot two-step platform for the dual glycosylation of peptides. By this strategy, we also performed the sequential glycosylation and biotinylation of peptides.
In recent years, N-heterocyclic carbenes (NHCs) have attracted considerable interest due to their unique features, which allow them to be used as ligands for organometallic catalysis, reagents in the synthesis of heterocycles, and efficient organocatalysts in umpolung transformations. In the latter sub-area of research many efforts have been devoted to the realization of highly stereoselective versions of the classical benzoin and Stetter reactions through optimal pre-catalyst design, to the discovery of new transformations, and to the umpolung of electrophiles alternative to aldehydes and pyruvates, mainly acylsilanes and Michael acceptors. In this thesis, our group has recently demonstrated the capability of linear and cyclic dialkyl α-diketones to undergo polarity reversal under thiazolium carbene catalysis in benzoin-type and Stetter reactions, and thus act as a novel class of acyl anion precursors. Contrarily, it has been observed that diaryl α-diketones do not undergo polarity reversal in the presence of (benzo)thiazolium carbenes but are engaged in a novel multicomponent reaction with water to efficiently give medicinally relevant 1,4-thiazin-3-one heterocycles. The umpolung reactivity of diaryl 1,2-diones, however, can be effectively triggered by different NHCs.
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Iloughmane-Gaspard, Hafida. "Ene reactivite d'alcenylsilanes et -germanes : synthese et stabilisation de metalloles du groupe 14." Toulouse 3, 1986. http://www.theses.fr/1986TOU30214.
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La synthese d'alcools allyliques organometalliques du groupe 14 (si,ge) a ete effectuee par oxydation de composes ethyleniques (photo-oxygenation ; epoxydation/rearrangement). Ces alcools ou leurs esters ont ete valorises en tant que precurseurs des premiers metalloles, isologues des cyclopentadienes, c-non substitues ou c-methyles qui ont ete stabilises par complexation-pi (fe,co). L'auteur decrit plus de 100 produits organometalliques nouveaux dont les structures moleculaires sont etablies par spectrometries de resonance magnetique nucleaire, de masse, photo-electronique et de diffraction des rayons x. Les mecanismes des reactions de cycloaddition, d'oxydation et d'elimination mises en jeu au cours de ce travail sont discutes
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Sow, Boubacar. "Development of the Domino Pericyclic Oxy-Cope/Ene /Claisen /Diels-Alder Reaction and the Synthesis of Complex Bicyclo[3.3.1]alkenones." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/30344.
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This thesis is a dissertation to support the development of new domino pericyclic oxy-Cope/ene/Claisen/Diels-Alder reaction, diversity oriented synthesis of PPAPs scaffold via sequential one pot cascade reaction and ethyl aluminum sesquichloride catalyzed highly hindered Diels-Alder reaction.
The first part concentrates on the domino pericyclic oxy-Cope/ene/Claisen/Diels-Alder reaction. As a result of this study, we have developed a general methodology for rapidly constructing complex diterpenes and discovered a thermal oxy-Cope/ene/Claisen/Claisen rearrangement, applied to the synthesis of trans decalin benzofurans.
The second part involved the development of an efficient synthetic approach towards bicyclo[3.3.1]nonenone core found in many natural products, via a sequential Diels-Alder/gold(I)-catalyzed 6-endo-dig cyclization and its application to the synthesis of a diversified library of PPAPs.
Finally, we have developed an efficient synthetic methodology for the formation of cyclohexene rings bearing quaternary carbon centers via an ethyl aluminum sesquichloride mediated highly hindered Diels-Alder reaction. This method solved an important problem encountered in the synthesis of many natural products including PPAPs. This methodology opened new opportunities in the total synthesis of PPAPs.
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Burry, Lori Carolyn. "Facial selectivity in the Diels-Alder reaction of some inverse electron demand 1,3-cyclopentadienes and a tandem-ene approach to the synthesis of a linear triquinane." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ36200.pdf.
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Gambera, Giovanni. "Studies toward the synthesis of the guaianolide skeleton : an intramolecular hetero Diels Alder approach and a carbonyl ene approach." Thesis, Loughborough University, 2006. https://dspace.lboro.ac.uk/2134/25173.
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This thesis describes the efforts towards the synthesis of the guaiane-6,12-olide skeleton, which characterises the guaianolide family of bioactive natural compounds. Two approaches have been investigated: the intramolecular hetero Diels Alder (IMHDA) reaction and the intramolecular carbonyl ene reaction. This thesis has been divided in three sections: the first part gives a general background about the guaianolides, the second section describes the synthetic approaches we investigated and, finally, the third section reports the experimental details. The first section gives a brief overview about the biosynthesis, the biological activities of the guaianolides, and the most interesting synthetic approaches to obtain them. The second section describes the two different approaches we investigated and gives a theoretical background about the main chemical transformations used. At first, the IMHDA reaction approach is described: a brief overview of palladium catalysis and Diels Alder reaction is given, and it is followed by the results and discussion of our study. Similarly, a theoretical background of the Alder ene reaction is given, before the results and discussion of the intramolecular carbonyl ene reaction approach are described: particular importance is given to the reasoning that led to the assignment of the relative configuration of the cycloadducts obtained, and to the rationalisation of this stereochemical outcome. Finally, the third section gives a complete description of the experimental procedures followed, and of the experimental data for the synthetic studies performed in the previous chapter.
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CRUCIANI, PAUL. "Etude de la conia ene reaction catalysee par les complexes du cobalt (i) approche diastereoselective des squelettes de base des kauranes et des phyllocladanes." Paris 6, 1995. http://www.theses.fr/1995PA066574.
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Ce travail est divise en deux parties: la premiere partie est axee sur l'etude systematique de la conia ene reaction catalysee par les complexes du cobalt(i) en termes de regio-, chimio- et diastereoselectivites. Cette etude nous a conduit a proposer un mecanisme base sur une reaction de cycloisomerisation du motif enol-yne qui permet de justifier l'ensemble des resultats observes. Dans la deuxieme partie, nous avons applique les specificites de cette reaction a la synthese de diterpenes tetracycliques de la famille des kauranes et des phyllocladanes. La nature du catalyseur nous a notamment permis de realiser une approche du squelette des phyllocladanes basee sur trois reactions de cycloadditions: conia ene, 2+2+2 et 4+2 en un seul pot. Enfin, une utilisation judicieuse de cette catalyse a conduit a un renversement total de la diastereoselectivite en faveur du squelette de base des kauranes. Nous decrivons dans ce memoire la synthese des precurseurs ainsi que toutes les reactions de cycloadditions
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Poudel, Dhruba P. "Late-Stage Modification of Polyurethane Dendrimers Using Click Chemistry." Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1627490978861964.
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Zhurakovskyi, Oleksandr. "Pericyclic and related rearrangements for the synthesis of nitrogen heterocyclic ring systems." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:d7e4bbea-4009-4e7e-838c-46b4bb81bc13.
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The thesis describes synthesis and reactions of allene azides tethered to various functional groups and the application of the discovered cascade transformations towards the synthesis of radianspene J model system. Chapter 1 covers reactions of simple allene azides containing alkyl and cycloalkyl substituents. Thermal rearrangements of these substrates delivered isocyanides and azadienes via the proposed azatrimethylenemethane (ATMM) intermediates. On the other hand, vinylidenecyclopropanes (VDCPs) gave dramatically different products, as described in Chapter 2. A phenyl-substituted VDCP was transformed into an unstable polycyclic compound by a divinylcyclopropane rearrangement. Chapter 3 discusses allene azides tethered to furan, N-substituted pyrroles, and E- and Z-dienes. Depending on the structure of the starting material, products of formal (3+4)- or (2+3)-cycloaddition were formed. Finally, an application of the discovered cyclisation cascade towards total synthesis is described in Chapter 4. A model system of radianspene J was assembled using a key transannular cycloaddition of a macrocyclic allene.
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Dürr, Alexander B. Verfasser], Franziska [Akademischer Betreuer] [Schönebeck, Dieter [Akademischer Betreuer] Enders, and Gerhard [Akademischer Betreuer] Raabe. "Reactivity and selectivity in homogeneous nickel catalysis and in the formal conia-ene reaction : a computational and experimental approach / Alexander B. Dürr ; Franziska Schoenebeck, Dieter Enders, Gerhard Raabe." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1180542363/34.
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Dürr, Alexander B. [Verfasser], Franziska [Akademischer Betreuer] Schönebeck, Dieter [Akademischer Betreuer] Enders, and Gerhard [Akademischer Betreuer] Raabe. "Reactivity and selectivity in homogeneous nickel catalysis and in the formal conia-ene reaction : a computational and experimental approach / Alexander B. Dürr ; Franziska Schoenebeck, Dieter Enders, Gerhard Raabe." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1180542363/34.
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François, Benjamin. "Utilisation d’organoboranes fonctionnalisés pour la construction de structures polycycliques." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S114.
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Les composés organoborés constituent des outils remarquables en synthèse organique de par leur chimie très diversifiée. Les travaux présentés dans ce mémoire abordent de nouveaux aspects de leur réactivité. Une méthode de synthèse rapide et efficace de 9-hydroxyfluorènes est décrite via une séquence tandem Suzuki/ aldolisation phénolique. Ce processus a été ensuite étendu aux 9-aminofluorènes en ajoutant simplement comme troisième partenaire diverses amines au milieu réactionnel. Des hypothèses mécanistiques sont proposées pour rationaliser ces résultats expérimentaux. Dans une deuxième partie, est présentée une étude articulée autour de la mise en œuvre de réactions ène sur des diènes borylés 1,3. Les produits ainsi obtenus sont ensuite utilisés comme intermédiaires clé de structures polycycliques plus complexes. Enfin, le troisième chapitre est consacré à une nouvelle voie d'accès aux pyrroles C-fusionnés à partir de diènes cycliques borylés, ces derniers étant préparés par hydroboration d'énynes, bora-Wittig ou métathèse. Une grande diversité structurale est alors accessible à partir de ces précurseurs d'accès aiséOrganoboron compounds are remarkable tools in organic synthesis due to their very diversified chemistry. The work presented in this thesis addresses new aspects of their reactivity. A rapid and efficient synthesis of 9-hydroxyfluorenes is described via a tandem Suzuki/phenol aldolisation sequence. This process was then extended to 9-aminofluorenes by simply adding various amines to the reaction medium as the third partner. Mechanistic hypotheses are proposed to rationalize these experimental results. In a second part, was presented a study articulated around the implementation of ene reactions on borylated 1,3-dienes. The products thus obtained are then used as key intermediates of more complex polycyclic scaffolds. Finally, the third chapter is dedicated to a new access to C-fused pyrroles from borylated cyclic dienes, the latter being prepared by hydroboration of enynes, boron-Wittig or metathesis reactions. A great structural diversity is then accessible from these easily prepared precursors
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Denis, Isabelle. "Photodégradation des composés organiques volatils biogéniques dans l'atmosphère : étude de la réactivité du (beta)-pinène vis à vis des radicaux hydroxyles ; cas de la réactivité en milieu hétérogène." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10129.
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L'objectif de ce travail etait d'etudier la photodegradation du beta-pinene, composeorganique volatil biogenique, en presence de radicaux hydroxyles et de determiner l'impact de particules solides sur cette photodegradation. Des artefacts analytiques ont ete rencontres lors de la mise au point du protocole de prelevement et d'analyse, et provenaient de la degradation de l'espece organique sur le support de prelevement pendant la thermodesorption. L'application d'un calcul correctif a permis de minimiser les erreurs d'artefact. Les etudes cinetiques effectuees sur les experiences en milieu homogene et en milieu heterogene, n'ont pas mis en evidence d'influence significative des particules sur la constante cinetique de reaction du beta-pinene. Toutefois, l'identification des produits secondaires a montre des differences notables entre les deux types de simulation. Dans nos conditions experimentales, des reactions d'oxydation heterogene apparaissent en presence de particules, mais ces mecanismes heterogenes sont negligeables d'un point de vue cinetique par rapport aux processus homogenes impliquant les radicaux hydroxyles
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Jones, Charlotte E. S. "Enantioselective homogeneous catalysts for the synthesis of fluorinated organic compounds." Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/2611.
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This thesis is divided into three main results chapters that reflect the path my research took. In the first results chapter, the first organocatalyst for the carbonyl-ene reaction was discovered and found to give high conversion using 1,3-bis(3,5-bis(trifluoromethyl)phenyl)thiourea. Various carbonyl and alkene precursors were examined in the ene reaction in both catalysed and uncatalysed reactions. It was found that ene reactions using fluoral and ethyl trifluoropyruvate give higher rates of reaction when compared to other carbonyl compounds. A novel enantiopure thiourea was synthesised and the ene reaction was catalysed enantioselectively to 33% e.e. In an attempt to catalyse the reaction to a further extent a new thiourea bonded to a P(=S)R2 group was developed. However, the intramolecular hydrogen bonding of this catalyst was thought to be so strong that this it did not catalyse the reaction. The synthesis of a chiral phosphoric acid was achieved but this was an unsuccessful catalyst in the ene reaction. Two component achiral thiourea and chiral acids were also examined in the ene and Mannich-type reaction. The new easily synthesised thiourea for this reaction has an interesting intermolecular hydrogen bonding coordination in the solid state. Asymmetric fluorination of ketoesters using palladium is a dynamic kinetic resolution. In the 2nd chapter cationic palladium complexes were synthesised and used to determine the optimum parameters for bidentate ligands in this reaction. Four carbon chain phosphines were found to give the highest conversion for this reaction among those ligands tested such as 1,4-bisdiphenylphosphinobutane (bite angle 99º). A new bis-phosphinous amide chiral ligand was developed with a bite angle of 96.7º. The dichloropalladium complex of this phosphine was isolated and structurally characterised. The use of the palladium complex in asymmetric fluorination was attempted however this was found to be unsuccessful. Mechanistic studies reveal that the formation of the desired cationic catalyst did not occur under conditions shown to work well for other palladium phosphine complexes. The ligand was investigated further in hydrogenation reactions. The phosphinous amide was protected as its borane and was used in the rhodium catalysed hydrogenation of alkenes to give high conversion and up to 93% e.e. The borane protected phosphinous amide was also found to catalyse the hydrogenation of acetophenone using copper complexes with up to 84% e.e for the hydrogenation of acetophenone, although conversion was quite low.
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Béteille, Jean-Pierre. "Thermolyse eclair d'allyl-1 silacyclopentenes-3 : etude mecanistique et application a la synthese d'hydrogenosiloles et de leurs derives fonctionnels." Toulouse 3, 1988. http://www.theses.fr/1988TOU30156.
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La pyrolyse eclair d'allyl-1 silolenes-3 est effectuee. Elle permet d'obtenir des hydrogenosiloles ainsi que des siloles fonctionnels a liaison silicium-azote, -oxygene ou -fluor et des siloles a groupement aryle ou allyle lie au silicium. De la meme facon on etudie la pyrolyse d'allylgermolenes. Les mecanismes de reaction sont etudies
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Ramaya, Sharn. "Synthetic studies towards C-glycosyl amino acids : Part I, The synthesis of C-glycosyl amino acids using zinc reagents; Part II, Approaches towards the synthesis of C-glycosyl amino acids using an imino ene reaction." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390646.
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VASQUEZ, JEDDAH MARIE. "Design of a Multilayer Honey-Mimetic Antibacterial Wound Healing Device." Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2745713.
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Chen, PoYun. "Role of Ionic Liquid in Electroactive Polymer Electrolyte Membrane for Energy Harvesting and Storage." University of Akron / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1590688110146547.
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Giros, Audrey. "Synthèse et réactivité des disilanes : applications vers la synthèse de la 10-silatestostérone." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112412/document.
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Les travaux rapportés dans ce mémoire concernent la synthèse et la réactivité des disilanes, en vue de leur application vers la synthèse de la 10-silatestostérone. Dans un premier temps, l’intérêt potentiel de la cible choisie, la 10-silatestostérone, a été étayé au moyen d’exemples de molécules d’intérêt biologique présentant un atome de silicium, issus de la littérature. L’objectif de la silasubstitution serait d’empêcher la biotransformation de la molécule en composé aromatique potentiellement cancérigène. Enfin, la substitution en position 10 de l’atome de carbone quaternaire permet d’éviter l’introduction de substituants supplémentaires, susceptibles d’affecter l’activité hormonale de la molécule. Dans un second temps, nous avons optimisés les outils nécessaires à la synthèse de la 10-silatestostérone. Une nouvelle stratégie pour accéder à des disilanes non symétriques a été développée par réaction de déphénylation chlorative. Puis l’étude de la réaction de coupure hétérolytique de la liaison Si-Si de phényldisilanes non symétriques par piégeages des silylures ainsi générés et par une analyse par RMN ¹H a permis de mettre en évidence une sélectivité en faveur du phénylsilylure. Enfin cette réaction a été appliquée pour accéder à des composés carbonylés β-silylés par réaction d’addition-1,4 de silylcuprolithiens sur des composés carbonylés α,β-éthyléniques tels que le cyclohexènecarboxylate de méthyle, un modèle simplifié de l’ester bicyclique que nous envisageons d’utiliser pour apporter la partie C&D de la 10-silatestostérone. Enfin le troisième chapitre porte sur la synthèse des précurseurs de la 10-silatestostérone. Dans une première partie un disilane hautement fonctionnalisé, le 1-isopropényl-1-(3-oxopropyl)disilane a pu être préparé en mettant à profit la réaction de déphénylation chlorative. Puis la réaction ène intramoléculaire de cet aldéhyde a conduit au 1-méthyl-1-triméthylsilyl-2-méthylidène-1-silacyclohexan-4-ol précurseur du cycle A de la 10-silatestostérone ainsi qu’au 1,2-diméthyl-2-triméthylsilyl-1-silacyclohexane-1,4-diol issu d’un réarrangement hautement diastéréosélectif. Dans une seconde partie, est présentée la synthèse énantiosélective de la partie C&D de la 10-silatestostérone par une réaction clé de carboxylation de la dicétone d’Hajos-Parrish. L’étape suivante consistera à réaliser la coupure sélective du disilane porteur du cycle A, et à additionner le silylure ainsi généré sur l’ester α,β-insaturé bicycliqueThis thesis is devoted to the synthesis and the study of the reactivity of disilanes in order to involve them in the 10-silatesosterone synthesis. The first part focuses on the usefulness of 10-silatestosterone by developing some relevant examples, from the literature, of biologically active molecules containing a silicon atom. Thus in the testosterone field, the substitution of a carbon atom by a silicon one is supposed to avoid aromatization of the molecule during its biotransformation. Moreover the 10 position of the silasubstitution prevents from the introduction of new groups, which is known to affect the biological activity of the molecule. In the second part the chemical tools for the 10-silatestosterone synthesis are described. A new strategy has been developed to obtain non symmetrical disilanes by a chlorinative dephenylation sequence. The heterolytic cleavage of the Si-Si bond of non symmetrical phenyldisilanes has been studied by trapping the generated silylanion and by ¹H NMR experiments. Selectivity for the phenylsilylanion formation has been established. Finally this reaction was fully exploited to access to β-silylated carbonyl compounds after 1,4-addition of silylcuprates on α,β-unsaturated carbonyl compounds as methylcyclohexenecarboxylate, model of the C&D rings of 10-silatesosterone. The third part presents the 10-silatestosterone precursors synthesis. At First high functionalized 1-isopropenyl-1-(3-oxopropyl)disilane has been obtained by using the previously performed chlorinative dephenylation reaction. Then intramolecular ene reaction of this aldehyde leads to a mixture of 1-methyl-1-trimethylsilyl-2-methylidene-1-silacyclohexan-4-ol, which corresponds to the 10-silatestosterone A ring and 1,2-dimethyl-2-trimethylsilyl-1-silacyclohexane-1,4-diol coming from diastereoselective rearrangement. Eventually, enantioselective synthesis of 10-silatestosterone C&D rings was achieved through a sequence involving a Hajos-Parrish ketone carboxylation key step. Further work would consist on a selective cleavage of A ring disilane followed by the 1,4-addition of the generated silylanion on α,β-unsaturated bicyclic ester
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Somerville, Brian John. "Studies in enantioselective intermolecular ene reactions." Thesis, University of Strathclyde, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366920.
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Hall, Michael J. "Silicon tethered ene and allyl transfer reactions." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275314.
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Luengo, Arratta S. "Intramolecular ene reactions of functionalised nitroso compounds." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/20237/.
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This thesis concerns the generation of geminally functionalised nitroso compounds and their subsequent use in intramolecular ene reactions of types I and II, in order to generate hydroxylamine derivatives which can evolve to the corresponding nitrones. The product nitrones can then be trapped in the inter- or intramolecular mode by a variety of reactions, including 1,3-dipolar cycloadditions, thereby leading to diversity oriented synthesis. The first section comprises the chemistry of the nitroso group with a brief discussion of the current methods for their generation together with the scope and limitations of these methods for carrying out nitroso ene reactions, with different examples of its potential as a powerful synthetic method to generate target drugs. The second chapter describes the results of the research programme and opens with the development of methods for the generation of functionalised nitroso compounds from different precursors including oximes and nitro compounds, using a range of reactants and conditions. The application of these methods in intramolecular nitroso ene reactions is then discussed. Chapter three presents the conclusions which have been drawn from the work presented in chapter two, and provides suggestions for possible directions of this research in the future. This work concludes with a formal account of the experimental procedures.
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Thongkham, Somprasong. "Synthèse de lactones fonctionnalisées par réaction de thiol-ène et leur application à la préparation de polymères biodégradables de propriétés modulables." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30295.
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Le développement de nouveaux polymères durables dotés de performances améliorées avec un impact environnemental minimal est devenu une préoccupation majeure. Dans ce contexte, les polyesters aliphatiques attirent de plus en plus l'attention dans le domaine médical et les applications d'emballage, en raison de leur caractère biodégradable et de leurs propriétés physiques appropriées. La polymérisation par ouverture de cycle (ROP) est une méthode qui a été utilisée dans ces domaines pour accéder à une vaste gamme de polyesters ayant des structures différentes et bien contrôlées. L'un des monomères de type lactone bien connus pour la ROP est l'epsilon-caprolactone (epsilon-CL), un composé dérivé du pétrole. Une autre lactone dérivée de la biomasse est l'epsilon-décalactone (epsilon-DL). Cycle à 7 chaînons comme l'epsilon-CL, l'epsilon-DL est un monomère renouvelable qui attire de plus en plus d'attention. Le groupe butyle pendant en position epsilon a un impact important sur les propriétés mécaniques et thermiques ainsi que sur la vitesse de dégradation. Pour moduler encore plus ces propriétés, nous avons travaillé avec des monomères fonctionnalisés de structure proche pour assurer un comportement similaire en ROP. Premièrement, les monomères d'epsilon-CL- epsilon-fonctionnalisés ont été préparés à partir de l'acide 6-heptynoïque par une stratégie séquentielle à grande économie d'atome : une cycloisomérisation catalysée par un métal de transition suivie d'une réaction thiol-ène. Ensuite, leur copolymérisation avec l'epsilon-DL a été réalisée en utilisant un catalyseur bicomposant à base d'InCl3, un comportement de polymérisation contrôlée/vivante a été identifié et des copolymères à caractère aléatoire ont été obtenus. Grâce à cette stratégie, la préparation de copolymères présentant des groupes acides carboxyliques pendants a été développée. Enfin, la dégradation en conditions hydrolytiques et enzymatiques de ces copolymères fonctionnalisés a fait l'objet d'études approfondies, prouvant l'influence de notre nouveau monomère fonctionnalisé (sous forme déprotégé) sur la vitesse de dégradation du PDLThe development of new sustainable polymers endowed with improved performances but minimal environmental impact has become a major concern. In this context, aliphatic polyesters are attracting increasing attention in the medical field and packaging applications, due to their biodegradable character and suitable physical properties. Ring-opening polymerization (ROP) is a method that has been used in these areas to access a broad range of polyesters with different and well-controlled structures. One of the well-known lactone monomers for ROP is epsilon-caprolactone (epsilon-CL), a compound derived from petrochemical source. An alternative lactone monomer derived from biomass is epsilon-decalactone (epsilon-DL). Being a 7-membered ring as epsilon-CL, epsilon-DL is thus a renewable monomer that is attracting increasing attention. However, the pendant butyl group at epsilon-position has a large impact on mechanical and thermal properties as well as degradation rates. To modulate these properties, we have been working with the functionalized monomers of close structure to ensure similar behavior in ROP. First, the epsilon-functionalized-epsilon-CL monomers were prepared from 6-heptynoic acid by a sequential transition metal catalyzed cycloisomerization and subsequent thiol-ene reaction. Afterwards, their copolymerization with epsilon-DL has been explored including the identification of controlled/living polymerization using InCl3-based bicomponent catalyst and the confirmation of their random architecture. In addition, the preparation of copolymers featuring pendant carboxyl groups by post-modification steps have also been completely achieved. Finally, the hydrolytic and enzymatic degradation of these functionalized copolymers has been thoroughly investigated, proving the influence of our new functionalized monomer (in deprotected form) on degradation rates of PDL
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Spilling, Christopher D. "The intramolecular ene reactions of some unsaturated acyloins." Thesis, Loughborough University, 1986. https://dspace.lboro.ac.uk/2134/25592.
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The reaction of 3β-tosyloxy-5α-cholesta-5,6β-diol with potassium t butoxide in t-butanol has been further investigated. 5β-Hydroxy-4,5-secocholest-3-en-6-one was synthesised. It was shown to undergo an ene reaction in decalin in a sealed tube at 200°C to give primarily 3β-methyl-A-nor-5β-cholestan-5-o1 -6-one and 6β-hydroxy-4(5-6α) abeo-cholestan-5-one. These primary products were further modified under the reaction conditions to give 3-methyl-B-nor-5β-cholest-2-en-4-one and 5β-cholestan-5-ol-6-one respectively. The cyclohexane analogue, 3-methyl-3-(3-butenyl)-2-hydroxy-cyclohexanl- one was synthesised. Heating under reflux in decalin gave 3β,7αβ-dimethyl- 3αβ-hydroxy-octahydro-4H-inden-4-one; 5β,7αβ-dimethyl-3αβ-hydroxy-octahydro- 4H-inden-4-one and an unidentified minor product. The synthesis of 5-(2-propenyl)-5β-cholestan-2-ol-3-one was partially completed. The epimeric 5-(2-propenyl)-5β-cholestan-2-ol-3-one was synthesised. The ene reaction was observed in refluxing toluene giving 2α,5-(1-methylethano)-5α-cholestan-2β-ol-3-one and 3α,5-(methyethano)-5α-cholestan-3βol-2-one. The ketone analogue, 5-(2-propenyl )-5α-cholestan-3-one underwent an ene reaction in decalin in a sealed tube at 250°C to give 2α,5-(1-methylethano) -5α-cholestan-3-one.
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Diaf, Ilhem. "Développement de nouveaux processus de cyclisation de dérivés alléniques catalysés par des triflates métalliques et synthèse de molécules odorantes." Thesis, Nice, 2014. http://www.theses.fr/2014NICE4124.
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De nouveaux processus de cyclisation d’allènes fonctionnalisés catalysées par des triflates métalliques sont présentés. Deux stratégies ont été développées. Dans un premier temps, une réaction de type carbonyl-ène intramoléculaire à partir de cétones γ-alléniques est développée. Cette réaction se déroule dans des conditions très douces avec une charge catalytique en triflate de bismuth(III) de seulement 1 mol%. Cette stratégie a ensuite été étendue à d’autres dérivés cétones γ-alléniques. Les alcools diéniques résultants ont pu être engagés avec succès dans une réaction de type Diels-Alder menant à la formation de structures polycycliques fonctionnalisées avec de bons rendements et une excellente régio- et diastéréosélectivité. La cyclisation d’éthers d’énol catalysée par les triflates métalliques a été par la suite étudiée. Cette stratégie permet d’obtenir des dérivés cyclopentènes avec de bons rendements en utilisant seulement 0,1 mol% de triflate de bismuth(III). Des dérivés dihydrofuranes peuvent être également formés par cette stratégie. Ces produits résultent de l’attaque nucléophile du carbone central de l’allène sur l’éther d’énol activé. Cette réactivité a pu être inversée en utilisant un complexe d’or(I) comme catalyseur en présence d’un nucléophile externe, donnant ainsi naissance à des produits différents. Dans une dernière partie, des applications dans le domaine de la chimie des arômes et des parfums ont été développées. Des dérivés acétates et alcools alléniques ont été synthétisés et exposés à des tests olfactifs, révélant des tonalités olfactives intéressantes. Des notes fruitées et florales dominantes et des nuances vertes et boisées ont été détectéesNovel processes of metal triflate-catalyzed cyclizations of functionalized allenes are presented. Two strategies have been developed. In a first part, the intramolecular carbonyl-ene reaction with γ-allenic ketones is described. This reaction proceeds under very mild conditions using only 1 mol% of bismuth(III) triflate. The scope of this reaction was extended to several γ-allenic ketone derivatives, featuring various substitution patterns. The resulting dienols were successfully engaged in a Diels-Alder reaction allowing the formation of polycyclic functionalized frameworks in good yields with excellent regio- and diastereoselectivities. In a second part, the metal triflate-catalyzed cyclization of allenic-enol ethers is described. This reaction gives access to cyclopentene derivatives in good yields using only 0.1 mol% of bismuth(III) triflate. Dihydrofuran derivatives could also be formed using this strategy. This cycloisomerisation reaction proceeds through an initial enol ether activation, followed by the nucleophilic attack of the allene moiety. This reactivity could be inverted using a gold(I) catalyst, in the presence of an exogenous nucleophile, allowing the formation of different products. Within our interest in flavor and fragrance chemistry, allenic acetates and alcohols have been synthesized and subjected to olfactive evaluation, revealing dominant fruity and floral notes. Green and woody undertones have been detected as well
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Gonçalves, Renato Sonchini. "Síntese e caracterização de amino ácidos e ésteres n-(aminoalquil)-lactâmicos derivados do paba com potencial atividade biológica /." Bauru : [s.n.], 2010. http://hdl.handle.net/11449/99656.
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Orientador: Eduardo René Pérez GonzálesBanca: Alvicler Magalhães
Banca: Wanda Pereira Almeida
O Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, PosMat, tem caráter institucional e integra as atividades de pesquisa em materiais de diversos campi da Unesp
Resumo: Amino ésteres lactâmicos derivados do PABA e que podem ser potencialmente bioativos, por exemplo, como anestésicos locais, foram sintetizados com bons rendimentos por uma reação seletiva de SnAr de ácidos benzóicos com n-(3-aminopropil)-lactamas seguida por esterificação com aminoálcoois terciários. Produtos da N-arilação do N, N-dimetilformamida foram também obtidos através da esterificação direta do ácido 4-cloro-3-nitrobenzóico
Abstract: Lactamic amino esters PABA-related, and can potentially bioactive, for exemple, as local anesthetics were synthesized in good yields by a selective 'S IND. n'Ar reactions of benzoic acids with N-(3-aminopropyl)lactams followed by esteterification with tertiary aminoalcohols. Products of the N-arylation with N,N-dimethylformamide are also obtained through of direct esterification of 4-chloro3-nitrobenzoic acid
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Cheung, Chi Ming. "Intramolecular carbonyl ene reactions towards the synthesis of the paclitaxel CD ring." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268354.
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Oliveira, Fernando Paes de. "Ocorrência e caracterização molecular de Cryptosporidium spp. em bezerros leiteiros da região noroeste do Estado de São Paulo /." Araçatuba : [s.n.], 2010. http://hdl.handle.net/11449/94693.
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Resumo: Um total de 196 amostras fecais de bezerros leiteiros mestiços, de 7 a 30 dias de idade de ambos o sexos foram colhidas em 31 propriedades com o objetivo de determinar a ocorrência de Cryptosporidium na região Noroeste do Estado de São Paulo, assim como caracterizar molecularmente as espécies envolvidas nesta parasitose. Realizou-se a análise microscópica pela técnica de coloração negativa com verde malaquita em todas as amostras de fezes. Para identificação molecular de Cryptosporidium, utilizou-se a reação de nested PCR, utilizando primers específicos para amplificação de fragmentos do gene codificador da subunidade 18S do RNA ribossômico e do gene da glicoproteína GP 60, submetendo o produto da PCR a sequenciamento e análise filogenética. Por meio de exame de fezes, foi observada positividade de 2% (4/196), por meio de microscopia, e de 10,7% (21/196) pela nested PCR. Como resultado do sequenciamento, foram identificadas quatro espécies de Cryptosporidium: C. parvum (subtipo IIa15G2R1) C. ryanae, C. bovis e C. andersoni. Esta descoberta de C. parvum subtipo IIaA15G2R1 na região estudada ilustra a utilidade da subtipagem. Embora estes resultados iniciais baseados em subtipos com GP60 sejam úteis para compreender a dinâmica de transmissão das espécies de Cryptosporidium, o número de amostras analisadas é relativamente pequeno e muito mais ainda pode ser pesquisado. É interessante notar que as informações de tipagem molecular com o gene 18S rRNA e a subtipagem com o gene GP60, permitem que os epidemiologistas possam rastrear as fontes de surtos das diferentes espécies de Cryptosporidium.Abstract: A total of 196 fecal samples from crossbred calves, 7-30 days old of both sexes were collected in 31 properties with the objective of determining the prevalence of Cryptosporidium in the northwestern region of São Paulo, as well as characterizing the molecular species involved in this parasite. We performed microscopic analysis by the technique of negative staining with malachite green in all stool samples. For molecular identification of Cryptosporidium, we used the reaction of nested PCR using specific primers for amplification of gene fragments coding for the 18S subunit ribosomal RNA gene and the glycoprotein GP 60 by subjecting the PCR product sequencing and phylogenetic analysis. By stool examination, positivity was observed 2% (4 / 196) by means of microscopy, and 10.7% (21/196) by nested PCR. As a result of sequencing, we identified four species of Cryptosporidium: C. parvum (subtype IIa15G2R1) C. Ryanair, C. bovis and C. andersoni. This discovery of C. IIaA15G2R1 parvum subtype in the studied region illustrates the usefulness of subtyping. Although based on these initial results with GP60 subtypes are useful for understanding the transmission dynamics of the species of Cryptosporidium, the number of samples is relatively small and much more can still be searched. It is interesting to note that the information of molecular typing with 18S rRNA gene and subtyping with the GP60 gene, allow epidemiologists can track sources of outbreaks of different species of Cryptosporidium.
Orientador: Luiz Claudio Nogueira Mendes
Coorientador: Marcelo Vasconcelos Meireles
Banca: Ricardo Velludo Gomes de Soutello
Banca: Katia Denise Saraiva Bresciani
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Silva, Domingos Jorge Ferreira da. "Estudo dos efeitos do nitrato de lítio na expansão de argamassas sujeitas a reação álcali-sílica /." Ilha Solteira : [s.n.], 2007. http://hdl.handle.net/11449/91469.
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Resumo: Várias pesquisas realizadas com compostos a base de lítio tem mostrado resultados satisfatórios na redução da expansão associada à reação álcali-sílica (RAS), mas ainda existem muitas dúvidas sobre seus mecanismos de ação. A presente pesquisa avaliou os efeitos de uma adição química a base de nitrato de lítio (LiNO3) na redução da expansão associada a RAS, utilizando várias dosagens. Os estudo dos efeitos do LiNO3 na RAS foi feito pelo método acelerado das barras de argamassa (ASTM C-1260) utilizando dois tipos de agregado reativo. Também foram realizados ensaios de expansão com uma adição mineral a base de cinza volante a fim de correlacionar os efeitos de uma adição mineral com uma química na redução da expansão devido a RAS. Ensaios de resistência à compressão e trabalhabilidade foram realizados também buscando algum efeito do LiNO3 nestas propriedades. Os resultados do ensaio ASTM C-1260 indicaram que as adições de lítio foram efetivas na redução da expansão para os dois tipos de agregados reativos, sendo que para as condições e materiais utilizados na presente pesquisa foi necessário uma de adição de LiNO3 com relação molar (Li2O/Na2Oeq) de 7,00 para reduzir a expansão ao valor aceitável pela norma de 0,10% aos 16 dias. Foi observado também intensidades de redução da expansão diferentes entre os dois tipos de agregados estudados devido a diferença de reatividade dos mesmos. Verificou-se um limite de adição de lítio para o basalto, onde não havia mais redução significativa de expansão com o aumento da dosagem de adição. Observou-se também que as misturas contendo LiNO3 reduziram a expansão ao longo dos 30 dias, enquanto nas misturas contendo FA a expansão continuou a aumentar ao longo do teste. Os ensaios de condição de trabalhabilidade e de resistência à compressão mostraram que o LiNO3 não afeta consideravelmente estas propriedades.Abstract: Lithium compounds have been shown satisfactory results for the reduction of the expansion due to alkali-silica reaction (ASR), but there are many doubts about its mechanisms of action. The present research evaluated the effects of a chemical addition to lithium nitrate based (LiNO3) on the reduction of expansion associated with ASR, utilizing several dosages. For the study of the effects of the LiNO3 on the ASR it was used the accelerated mortar bar method (ASTM C-1260), with two kinds of reactivate aggregate. Mortar bars were molded also with a mineral addition of fly ash based (FA) with the objective to compare the effects of a mineral addition with a chemistry on the expansion due ASR. Compressive strength and consistence index tests had been carried also for searching some effects of the LiNO3 at these properties. The results from ASTM C-1260 showed that the addition of LiNO3 were effective on the expansion reduction for two kinds of reactive aggregate, which current conditions and materials on this research required a LiNO3 addition with (Li/Naeq) of 7,00 molar ratio to decrease the expansion to an acceptable value of 0,10% on 16 days. Also, the intensity of the expansion reduction was observed between two kinds of studied aggregates by their reactivity difference. A lithium additive upper bound was verified for the basalt, where it did not have more significant reduction of expansion with the increase of the dosage of addition. Also, was observed that admixtures that contained LiNO3 have reduced the expansion trough 30 days, while on the admixtures that contained FA the expansion grew up. The results obtained for the compressive strength and consistence index tests showed no significant differences between mixtures with and without LiNO3 admixture.
Orientador: Jorge Luís Akasaki
Coorientador: Haroldo de Mayo Bernardes
Banca: Marco Antonio Morais Alcantara
Banca: Vladimir Antonio Paulon
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Lopes, Marissol Cardoso. "Comparação entre as técnicas de RT-PCR e inoculação intracerebral em camundongos para detecção do vírus da raiva em amostras mantidas por longos períodos em diferentes estados de conservação /." Araçatuba : [s.n.], 2008. http://hdl.handle.net/11449/94733.
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Orientador: Luzia Helena Queiroz da SilvaBanca: Avelino Albas
Banca: Silvana Regina Favaretto Lazarini
Resumo: As análises antigênica e genética são ferramentas importantes para o estudo da epidemiologia da raiva em uma região. A recuperação e reisolamento viral a partir de amostras conservadas por longos períodos em temperatura de congelamento é essencial para estudos retrospectivos. Porém, o tempo de conservação, associado a repetidos ciclos de congelamento e descongelamento, promove uma perda significativa na viabilidade do vírus, condição esta que pode ser contornada com a utilização de técnicas de biologia molecular, como a RT-PCR. Com o objetivo de verificar a viabilidade e detectar o RNA do vírus rábico, 95 amostras com diagnóstico positivo e armazenadas por 4 a 13 anos a -20 e -80ºC foram avaliadas por inoculação intracerebral em camundongos e RT-PCR. Apenas 33,6% (32/95) das amostras inoculadas em camundongos foram positivas, enquanto que a RTPCR detectou o genoma viral em 65,3% (62/95). Houve diferença estatisticamente significativa (p<0,0001) na viabilidade das amostras e na detecção do genoma viral na amostras armazenadas por mais de 10 anos, sendo a porcentagem de positividade de 22,1% e 59,7%, respectivamente. O presente estudo confirma a importância da RT-PCR na detecção do genoma viral em amostras conservadas por longo período de tempo, incluindo aquelas em estado visível de decomposição.
Abstract: The antigenic and genetic analyses are important tools for retrospective study of rabies epidemiology in a region. The recovery and viral re-isolation from samples conserved for long periods in freezing temperature are essential for these studies. However, time conservation, associated with temperature variations, causes a significative virus viability loss. On the other hand, molecular tools, such as RT-PCR, can overcome this condition. For this purpose, 95 positive samples stored for 4 to 13 years at -20 and -80ºC were evaluated by intracerebral inoculation in mice and RT-PCR. Of this total, only 33,6% (32/95) had been positive in the intracerebral inoculation, while RT-PCR detected the viral genoma in 65.3% (62/95). It had a significant difference (p>0,0001) in the viability of the samples and the detention of the viral genoma from those samples store for more than 10 years and the percentage of positivity reached 22,1% and 59,7%, respectively. The present study confirms the importance of the RT-PCR technique for detection of viral genoma in old samples, including those in apparent state of decomposition.
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