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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-aSumoreeah, Ravi Leckman January 2002 (has links)
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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Structure and efficiency in general species catalysisPercy, J. M. January 1986 (has links)
No description available.
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Highly excited molecules and the interstellar maserHolland, Simon Michael January 1999 (has links)
No description available.
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Copper(I) activivation of unsaturated compounds towards reaction with nucleophilesBainbridge, Michael John January 2003 (has links)
No description available.
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Novel radical based routes to pyrrolidine trans lactamsAjavakom, Anawat January 2003 (has links)
No description available.
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The development of enantioselective receptors for amino acid derivativesShepherd, Emma J. January 2000 (has links)
No description available.
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Generation and application of non-stabilised 1,3-dipolesAlanine, Alexander Irving Derek January 1990 (has links)
No description available.
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Spectroscopy and structure of jet cooled aromatics and van der Waals complexesWalters, Alan January 1991 (has links)
No description available.
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Vibrational studies of inorganic and organometallic compoundsDavies, C. L. January 1987 (has links)
No description available.
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\"Transferência de carga e ligação de hidrogênio intramolecular em derivados de 9-aminoacridina\" / \"Intramolecular charge and hydrogen bon transfer in 9-aminoacridine derivatives\"Pereira, Robson Valentim 25 August 2006 (has links)
Neste trabalho, o corante 9-aminoacridina foi derivatizado com compostos vinílicos que possuem grupos retiradores de elétrons. A incorporação destes leva à mudanças nas propriedades fotofísicas dos derivados, tais como deslocamentos para regiões de menor energia nos espectros de absorção e emissão, sugerindo a presença de transferência de carga intramolecular (ICT). Os estudos de fluorescência resolvida no tempo confirmam este processo para os derivados. Este estado ICT possui um tempo formação na faixa de 150 300 ps e um tempo de vida entre 1 3 ns, que depende do solvente. Os derivados que apresentam pelo menos um grupo carbonila como retirador de elétron, possuem um tempo de vida longo na faixa de 8 10 ns, atribuído à emissão do enol, formado a partir da conjugação estendida por ponte de hidrogênio. A polimerização destes derivados com o ácido metacrílico promoveram mudanças em suas propriedades fotofísicas estacionárias e resolvidas no tempo devido à quebra da conjugação  estendida. Este fato é ilustrado pelos espectros de absorção e emissão que mostram bandas estruturadas, deslocadas para a região de maior energia e um decaimento monoexponencial, semelhante ao observado com 9-aminoacridina. Anisotropia de fluorescência resolvida no tempo mostra que nos copolímeros o tempo de relaxação rotacional do corante é muito sensível à mudança conformacional do poli (ácido metacrílico) com o pH, possibilitando assim o estudo da dinâmica deste polímero em solução aquosa. / In this work, the dye 9-aminoacridine was derivatized with vinylic compounds containing electron withdrawing groups. The incorporation of these groups leads to changes in the photophysical properties of the dye, such a red shift in the absorption and emission spectra, suggesting the presence of intramolecular charge transfer (ICT) effect. Time-resolved studies have confirmed such process in all derivatives. This ICT state has a risetime in the range 150 300 ps and a fluorescence lifetime between 1 3 ns, that depends of the solvent. The derivatives with at least one carbonyl group as electron withdrawing, have an additional lifetime in the range of 8 10 ns, attributed to the enol emission formed by the extended conjugation. The polimerization of these derivatives with methacrylic acid induces changes in the stationary and time-resolved properties of the dye due to the breaking of the extended conjugation. This fact is illustrated by the absorption and emission spectra that show structured bands with a blue shift, and a monoexponencial decay, similar to the behavior of 9- aminoacridine. Time-resolved fluorescence anisotropy of the bound dye shows that the copolymers have a segment relaxation of the chain is very sensitive to the change in the conformational shape of poly (methacrylic acid) with pH, and such a process is well indicated by following the rotational relaxation of the dye.
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