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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Pyrolytic Study of 2-Azidocyclopentanone and 2-Azido-1-cyclohexylethanone

Chen, I-ying 06 August 2004 (has links)
Flash vacuum pyrolysis(FVP)of 2-Azidocyclopentanone gave three products:3,4-dihydro-2-pyridone¡A2-cyclopentylidene- cyclopentanone¡A3-hydroxypyridine. Flash vacuum pyrolysis(FVP)of 2-Azido-1-cyclohexylethanone gave the dimer: cyclohexyl-[4-cyclohexyl-1(3)H-imidazol-2-yl]ketone and trimer: 2,3-dicyclohexanecarbonyl-5- cyclohexylpyrazine
2

Pyrolytic Study of 2-Azido-1-(2-furanyl)ethanone and 2-Azido-1-(2-pyridinyl)ethanone

YU, CHENG-FEI 16 July 2003 (has links)
Flash vacuum pyrolysis(FVP)of 2-Azido-1-(2-furanyl)ethanone gave the dimer : [2-(2-formylfuranyl)-4-(2-furanyl)imidazole] and the trimer : (2,3- furanoyl -5-furanylpyrazine) Flash vacuum pyrolysis(FVP)of 2-Azido-1-(2-pyridinyl)ethanone gave the dimer : [2-(2-formylpyridyl)-4-pyridin-2-ylimidazole]
3

Two-point vertical force-velocity profile with model predicted maximal theoretical force

Lipsius, Lauren 13 October 2021 (has links)
Vertical jump performance is a key component of sporting success. In order to improve jump height, athletic assessments using constrained vertical jumps have been created to inform training decisions. The vertical force-velocity (FV) profile is a protocol that involves an athlete performing a series of squat jumps with multiple loads to create an athlete profile that is used to assess lower limb strength and speed performance and provide training recommendations. Yet, some practitioners avoid force-velocity profiling having expressed concerns about athlete safety during heavily loaded jumps, or the time cost of testing. As a simpler, faster and safer assessment, an unloaded squat jump, and a maximal voluntary isometric mid-thigh pull (IMTP) have been used to provide general training recommendations. These basic tasks have yet to provide the array of FV profile metrics or the accuracy of the training recommendations developed from the standard vertical FV profile protocol. Fortunately, due to the similarity of these IMTP and jump task metrics and the standard FV profile it may be possible to predict the same vertical FV metrics and training recommendations using multiple athlete measures, that include IMTP and jump task metrics and predictive modeling. Therefore, the purpose of this paper is to determine if an unloaded squat jump and an IMTP, alongside other athlete variables, can be used to create an athlete vertical FVP and training recommendation comparable to the standard protocol. / Graduate
4

1. Pyrolytic Study of Arylmethylazides 2. Pyrolytic Study of 2-Amino-3-methylpyridine and its Derivatives

Lee, Chin-Fan 27 June 2001 (has links)
Flash vacuum pyrolysis(FVP) of azidomethylthiophene,via a nitrene intermediate,gave two products,a dimer (thienylmethylidene-thienylamine) and a trimer (N,N`-dithienyl methylidene-thienylmethylidene diamine).The trimer underwent cyclization and dehydrogenation to afford 2,4,5-trithienylimidazole. However by the same route, FVP of azidomethylbenzo[b]furan produced only a trimer(dibenzo[b]furylmethylidene-N,N'-benzo[b]furylmethyl amine).
5

Pyrolytic Study of 2-Azidoacetophenone and 2-Azido-1-(2-thienyl)ethanone

Lin, Tsung-Te 02 July 2002 (has links)
Flash vacuum pyrolysis (FVP) of 2-azidoacetophenone gave the dimer 2-benzoyl-4- phenylimidazole and the trimer: 2,3-dibenzoyl-5-phenylpyrazine. Flash vacuum pyrolysis of 2-azido-1-(2-thienyl)ethanone gave the dimer: 2-(2-fromylthienyl)-4-(2-thienyl)imidazole and 2-formylthiophene.
6

Pyrolytic Study of 2-Azido-1-(1-methyl-2-pyrryl)ethanone and 2-Azido-1-(2-benzo[b]thienyl)ethanone

Lin, Hsiao-Yu 26 June 2003 (has links)
Flash vacuum pyrolysis (FVP) of 2-azido-1-(1-methyl-2-pyrryl)ethanone and 2-azido-1- (2-benzo[b]thienyl)ethanone gave nitrene by elimination of one nitrogen molecule. When 2-azido-1-(1-methyl-2-pyrryl)ethanone as a precorsor, the reactive nitrene readily underwent self-condensation to give 2-(1-methyl-2-formylpyrryl)-4-(1-methyl-2- pyrryl)imidazole, it¡¦s isomer and 2,4,5-tri(1-methyl-2-formylpyrryl) imidazole. While 2-azido-1-(2-benzo[b]thienyl)ethanone as a precorsor, the reactive nitrene readily underwent self-condensation to give 2-2-formylbenzo[b]thienyl-5-(2-benzo[b]thiophen-2-yl)imidazole. The mechanism for the formation of products of self-condensation reaction from FVP of 2-azido-1-(1-methyl-2-pyrryl)ethanone and 2-azido-1-(2-benzo[b]thienyl) ethanone will be discussed.
7

Isoxazolo- et Triazolo-pyrimidines - Aspects synthétiques et comportement en pyrolyse-éclair sous vide

Laurent, Sophie 01 October 1993 (has links)
Parmi les diverses méthodes de synthèse décrites dans la littérature, la réaction des o-aminoesters avec orthoesters, suivie de cyclisation par une amine aliphatique ou aromatique constitue une voie efficace pour la formation de pyrimidines condensées à d'autres hétérocycles. Cette séquence réactionnelle a été appliquée pour l'obtention des isoxazolo[5,4-d]pyrimidiones et des triazolo[4,5-d]pyrimidinones. Cependant, dans certains cas, lorsque l'imidate intermédiaire porte un groupement méthyle, le processus de cyclisation peut être totalement inhibé. Une séquence alternative consiste en la condensation de l'orthoester avec un o-aminoamide. De nombreuses isoxazolo- et triazolopyrimidinones non décrites ont été formées selon ces deux méthodes qui permettent d'introduire simulténaément des substituants en position 5 et 6 sur le cycle pyrimidinone. La première méthode, réalisée au départ d'o-aminonitriles conduit à des iminopyridines qui sont transformées en aminopyrimidines par réarrangement de Dimroth. Une étude en spectrométrie de masse et en pyrolyse-éclair sous vide a révélé que les dérivés de l'isoxazole sont d'excellents précurseurs de nouveaux hétérocumulènes RN=C=C=C=X. Ces cumulènes sont classés en trois catégories selon que X est en O, NH ou NR'. - Formation des iminopropadiénones, RN=C=C=C=O. - Formation des diiminopropadiènes, RN=C=C=C=NH. - Formation des diiminopropadiènes, RN=C=C=C=NR'. Nous nous sommes également intéressés à la spectrométrie de masse et à la pyrolyse de quelques triazolopyrimidines. En impact électronique, les 3-phényltriazolopyrimidines perdent de l'azote pour générer une structure alpha-cétocétèninime ou alpha-iminocétène tandis que la pyrolyse conduit au système pyrimidoindole.
8

1.Pyrolytic Study of 3-Furylmethylazide 2.Synthesis and Chemistry of 5,6-Dimethylene-5,6-dihydrobenzofuran

Lin, Ya-Mei 31 July 2001 (has links)
Flash vacuum pyrolysis (FVP) of azidomethylthiophene, via a nitrene intermediate, gave a trimer (N,N`-trifurfurylidene-furfurylidene diamine). Use three kinds of methods to synthies benzofuran compound and gain the product by using the third method.
9

New cyclisations of iminyl radicals generated by flash vacuum pyrolysis

Ieva, Maria January 2012 (has links)
The formation of iminyl radicals from a range of precursors, including hydrazone imines and oxime ethers, under FVP conditions is well documented in the literature.1 Once formed, the iminyl radical can undergo cyclisation onto various aromatic ring systems including phenyl rings, thiophenes and furans to form new fused aromatics.2 The aim of this thesis was to expand the scope of cyclisation of iminyl radical onto pyrrole-type rings and 2-azole rings, generating novel heterocyclic cores via pyrolysis of the corresponding oxime ether precursors. In addition, the cyclisation of iminyl radicals onto C-C double bonds was investigated and afforded isoquinolines shown in Scheme II, providing a new way to synthesise these heterocyclic cores. Mechanistic predictions were supported by DFT calculations in which the thermodynamics and kinetics of the systems were established and the products of iminyl cyclisation reactions were characterised using a range of 2D NMR experiments.
10

N-amino heterocycles : applications in flash vacuum pyrolysis

Rozgowska, Emma Jayne January 2011 (has links)
Routes to N-amino heterocycles were reviewed and findings applied to generate flash vacuum pyrolysis (FVP) precursors of two types - ketene generators and azol-1-yl radical generators. N-Amino heterocycles can be used as nitrogen radical generators, the N-N bond being homolytically cleaved at furnace temperatures of approximately 850 °C. A number of 2-substituted benzimidazoles were synthesised and subsequently Naminated. The 2-arylbenzimidazole precursors 1-amino-2-(2-methylphenyl)-1Hbenzimidazole and 1-amino-2-(2-ethylphenyl)-1H-benzimidazole were synthesised and subjected to FVP. The hydrogen transfer processes of the resulting azol-1-yl radicals were investigated. Pyrolysis of 1-amino-2-(2-methylphenyl)-1Hbenzimidazole resulted in three products; 2-(2-methylphenyl)-1H-benzimdazole, 11H-benzo[4,5]imidazo[1,2-a]isoindole and 1-(2-methylphenyl)-1Hbenzo[ d]imidazol-2-amine. Pyrolysis of 1-amino-2-(2-ethylphenyl)-1Hbenzimidazole resulted in five products, four of which have been successfully isolated and identified as 2-(2-ethylphenyl)-1H-benzimidazole, 5,6- dihydrobenzo[4,5]imidazo[2,1-a]isoquinoline, 1-(2-ethylphenyl)-1Hbenzo[ d]imidazol-2-amine and 11-methyl-11H-benzo[4,5]imidazo[2,1-a]isoindole. The mechanism of formation of most products is initiated by hydrogen atom transfer to the azol-1-yl radical position. N-Aminopyrazole was reacted with 5-methoxymethylene-2,2-dimethyl-1,3-dioxane- 4,6-dione to form the corresponding 5-(N-aminopyrazolyl)methylene derivative, which, when subjected to FVP, eliminates acetone and carbon dioxide to form a methyleneketene. This subsequently undergoes a [1,3]-hydrogen shift giving an imidoylketene which can collapse onto the neighbouring nitrogen atom forming pyrazolo[1,2-a][1,2,3]triazin-5-ium-4-olate (a novel heterocyclic mesomeric betaine system) or cyclise onto the adjacent carbon atom to yield a pyrazolopyridazinone. On variation of the furnace temperature it was apparent the former forms at relatively moderate temperatures (~500 °C) whereas the latter begins to predominate as the furnace temperature increases (~700 °C). The relationship between these kinetic and thermodynamic products was modelled using DFT calculations. By using substituted pyrazole precursors, substituents could be incorporated into all three available positions around the pyrazole ring. Using substituted acrylic esters as alternative imidoylketene generators, substituents could also be incorporated into both available positions in the pyridazinone ring. All corresponding betaine and pyrazolopyridazinone products were isolated and characterised.

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