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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

The Hydrolysis of α-(Benzenesulfonyl)-Acetophenone

Looney, Jesse M. 01 1900 (has links)
In view of the unexpected behavior of α-(benzenesulfonyl)-acetophenone toward hydrolysis and because of the possible physiological importance of its derivatives it was deemed of interest to make a further study of the hydrolysis of this compound. It was decided to study both the acid and basic hydrolysis of this compound. The problem consisted of finding a satisfactory means of analyzing the hydrolysis products, and carrying out the hydrolysis under the different conditions.
2

I. The addition of nitrosyl halides to isobutylene.

Erickson, Wallace Alfred, January 1939 (has links)
Thesis (Ph. D.)--University of Chicago, 1936. / Lithoprinted. "Private edition, distributed by the University of Chicago Libraries, Chicago, Illinois."
3

Aza-analogues of distyrilbenzene (DSB) synthesis, structures, and properties of 1,4-phenylenediamine bisimines (PDABI)

Murphy, Richard F., January 2006 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 30, 2007) Includes bibliographical references.
4

The carbethoxylation products of p-aminoacetophenone and p-dimethylaminoacetophenone

Chu, Chao-Yuan 25 May 1948 (has links)
The carbethoxylation product of p-aminoacetophenone with diethyl carbonate by means of sodium amide has been proved to be ethyl p-acetylphenylcarbamate instead of ethyl p-aminobenzoylacetate. Thus the amino group was shown to be more active than the methyl ketonic. group tow ard carbethoxylation. Attempt at further carbethoxylation of this carbamate were unsuccessful.
5

A-(Substitutedbenzenesulfonyl)-Substitutedacetophenones

Thomas, John Wylie 01 1900 (has links)
This thesis discusses the preparation of a-(o-nitro-p-methylphenylmercapto)-acetophenone by the reaction between acetophenone and o-nitro-p-methylbenzenesulfenyl chloride in boiling chloroform. The use of stannous chloride in glacial acetic acid for the reduction of nitro groups to amino groups was found generally satisfactory in spite of the difficulty often met with in isolating the amino product.
6

Acetophenone Derivatives; N-Diphenylmethyl and N-Fluorenyl Piperidines

Middleton, William J. 08 1900 (has links)
This thesis is a study of α-(4-aminophenylsulfonyl)-acetophenone derivatives; n-diphenylmethyl and n-fluorenyl piperidines.
7

Reactions using whole cell biocalytic lens culinaris (lentil) / ReaÃÃes biocatalÃticas usando cÃlulas Ãntegras de Lens culinaris (Lentilha).

Daniele Alves Ferreira 23 October 2012 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / This paper describes the use of seeds of lentil (Lens culinaris) as intact plant system in biocatalytic reactions of reduction and hydrolysis. Initially, some plant sources were evaluated for their action in the biocatalytic reduction of aromatic ketone acetophenone. The plants that showed positive results in the reduction reaction underwent determination of their protein content by the methods of Lowry and Bradford. Lens culinaris was plant species revealed that most relevant biocatalytic activity, in agreement with their high protein content (1.33 mg / mL and 1.07 mg / mL according to Bradford and Lowry methods, respectively), and thus The plant was selected for further study. Subsequently, always using the model substrate acetophenone as the reaction parameters were optimized: concentration of biocatalyst; reaction kinetics; stirring speed the reaction medium. After selecting these parameters, the bioreduction reactions were extended to other derivatives of prochiral acetophenone, which were observed with bioconversions yields and enantiomeric excess (ee) ranging from low to high percentages. Generally, were observed steric and electronic influences due to the type and relative position of the various substituents on aromatic compounds. In the case of substrates containing two different functional groups susceptible to reduction, low chemoselectivity observed. Investigated also other carbonyl compounds such as aliphatic and aromatic ketones, aromatic aldehydes and aromatic nitro compounds. In addition investigated the possibility that hydrolytic action from compounds belonging functions esters, amides and nitriles. The yields of the reactions were calculated using Gas Chromatography coupled with Mass Spectrometry (GC-MS) and Nuclear Magnetic Resonance Hydrogen (1H NMR). The enantiomeric excess (ee) were determined by High Performance Liquid Chromatography (HPLC) equipped with chiral columns. / Este trabalho relata a utilizaÃÃo das sementes de lentilha (Lens culinaris) como sistema Ãntegro de planta em reaÃÃes biocatalÃticas de reduÃÃo e hidrÃlise. Inicialmente, algumas fontes vegetais foram avaliadas quanto sua aÃÃo biocatalÃtica na reduÃÃo da cetona aromÃtica acetofenona. Os vegetais que revelaram resultados positivos na reaÃÃo de reduÃÃo foram submetidos à determinaÃÃo do seu teor de proteÃnas atravÃs dos mÃtodos de Lowry e Bradford. Lens culinaris foi à espÃcie vegetal que revelou atividade biocatalÃtica mais relevante, em acordo com seu alto teor de proteÃna (1,33 mg/mL e 1,07 mg/mL, segundo os mÃtodos de Bradford e Lowry, respectivamente), e assim, foi o vegetal selecionado para estudos mais aprofundados. Posteriormente, utilizando sempre a acetofenona como substrato modelo foram otimizados os parÃmetros reacionais: concentraÃÃo do biocatalisador; cinÃtica de reaÃÃo; velocidade de agitaÃÃo e meio reacional. ApÃs seleÃÃo desses parÃmetros, as reaÃÃes de biorreduÃÃo foram estendidas a outros derivados prÃ-quirais da acetofenona, onde foram observadas bioconversÃes com rendimentos e excessos enantiomÃricos (ee) que variaram de baixas a elevadas porcentagens. De modo geral, foram observadas influencias eletrÃnica e estÃrica devidas ao tipo e a posiÃÃo relativa dos diferentes substituintes nos compostos aromÃticos. No caso de substratos contendo dois grupos funcionais diferentes suscetÃveis de reduÃÃo, foi observada baixa quimiosseletividade. Foram investigados tambÃm outros compostos carbonilicos, como: cetonas alifÃticas e aromÃticas, aldeÃdos aromÃticos e nitrocompostos aromÃticos. Em adiÃÃo foi investigado a possibilidade de aÃÃo hidrolÃtica a partir de compostos pertencente Ãs funÃÃes Ãsteres, amidas e nitrilas. Os rendimentos das reaÃÃes foram calculados utilizando Cromatografia Gasosa acoplada à Espectrometria de Massas (CG-EM) e RessonÃncia MagnÃtica Nuclear de HidrogÃnio (RMN 1H). Os excessos enantiomÃricos (ee) foram determinados atravÃs de Cromatografia LÃquido de Alta EficiÃncia (CLAE) equipada com colunas quirais.
8

Efforts Towards Greener Photocatalysis and Streamlining Catalyst Design

Karp, Lindsey January 2021 (has links)
Photocatalysis is a robust synthetic tool capable of breaking and assembling chemical bonds using single electron chemistry. This is achieved through the catalytic conversion of light energy to chemical energy in situ, such that the photons being delivered are themselves reagents. Herein, an inexpensive and environmentally-benign platform for scaling up photocatalytic reaction is disclosed, harnessing blue light naturally emitted by deep-sea bioluminescent bacteria. Photobacterium angustum GB-1 was demonstrated to photoexcite both polypyridyl organometallic chromophores and organic dyes at short molecular distances, enabling photocatalysis without any external energy-consuming lamps.While improving the eco-friendliness of photocatalysis itself, we also present a method to use photocatalysis for environmental remediation. Using visible light, a nontoxic organic photosensitizer, and oxygen, we demonstrate the controlled oxidative depolymerization of polystyrene—including polystyrene retrieved from waste receptacles in Havemeyer—to acetophenone. This method is based on results obtained in the controlled aerobic deannulation of cycloalkanes, which is also discussed herein. Lastly, a means by which catalysis itself can be made more cost, resource, and time effective is presented. An innovative computational platform in development predicts new catalysts for reactions currently energetically inaccessible. In collaboration with the developers, we present experimental validation of their theoretical predictions, as well as perform the synthesis of a de novo fluorinated thiazolium precatalyst calculated to significantly lower the energetic barrier of an otherwise energetically prohibitive Stetter reaction.
9

Fluorosolvatochromism of furanyl- and thiophenyl-substituted acetophenones

Friebe, Nadine, Schreiter, Katja, Kübel, Joachim, Dietzek, Benjamin, Moszner, Norbert, Burtscher, Peter, Oehlke, Alexander, Spange, Stefan 15 February 2016 (has links) (PDF)
A series of para-substituted acetophenones bearing a furanyl or a thiophenyl moiety show a large Stokes-shift, which is a function of various solvent properties. Photophysical properties such as emission lifetime of the compounds have been determined using time-correlated-single photon counting to secure the intrinsic fluorescence behaviour. The solvent dependent position of the UV/Vis emission band [small nu, Greek, tilde]max,em of the compounds has been measured in 26 various solvents. The influence of the solvent on [small nu, Greek, tilde]max,em is of very complex nature and mathematically analysed by multiple square linear solvation energy (LSE)-correlation analysis using Catalán's four-solvent parameter set. Solvent acidity has a strong influence on the bathochromic shift of 2,5-disubstituted furan derivatives compared to the non-5-substituted furan and thiophene derivatives, which show a contrary behaviour. Therefore, the 5-cyanofuranyl-substituted acetophenone derivative is useful as a probe for measuring environmental properties by fluorescence spectroscopy. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
10

Fluorosolvatochromism of furanyl- and thiophenyl-substituted acetophenones

Friebe, Nadine, Schreiter, Katja, Kübel, Joachim, Dietzek, Benjamin, Moszner, Norbert, Burtscher, Peter, Oehlke, Alexander, Spange, Stefan 15 February 2016 (has links)
A series of para-substituted acetophenones bearing a furanyl or a thiophenyl moiety show a large Stokes-shift, which is a function of various solvent properties. Photophysical properties such as emission lifetime of the compounds have been determined using time-correlated-single photon counting to secure the intrinsic fluorescence behaviour. The solvent dependent position of the UV/Vis emission band [small nu, Greek, tilde]max,em of the compounds has been measured in 26 various solvents. The influence of the solvent on [small nu, Greek, tilde]max,em is of very complex nature and mathematically analysed by multiple square linear solvation energy (LSE)-correlation analysis using Catalán's four-solvent parameter set. Solvent acidity has a strong influence on the bathochromic shift of 2,5-disubstituted furan derivatives compared to the non-5-substituted furan and thiophene derivatives, which show a contrary behaviour. Therefore, the 5-cyanofuranyl-substituted acetophenone derivative is useful as a probe for measuring environmental properties by fluorescence spectroscopy. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

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