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Binkley, Meisha A. "Aryl Acetate Phase Transfer Catalysis: Method and Computation Studies." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2680.
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Brief explanation and history of cinchona based Phase Transfer Catalysis (PTC). Studied aryl acetates in PTC, encompassing napthoyl, 6-methoxy napthoyl, phenyl and protected 4-hydroxy phenyl acetates. Investigated means of controlling the selectivity of the PTC reaction by changing the electrophile size, the ether side group size or by addition of inorganic salts. Found that either small or aromatic electophiles increased enantioselectivity more than aliphatic electrophiles, and that increasing the size of ether protecting group also increased selectivity. Positive effects of salt addition included either decreasing reaction time or increasing enantiomeric excess. Applied findings towards the synthesis of S-equol. Computational experiments working towards deducing the transition state between PTC and aryl acetate substrates.
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Won, Chee-Youb. "Depolymerization of nylon 6,6 in the presence of phase transfer catalyst." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/8707.
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Munro, A. J. M. "Studies in the use of TDA-1 as a phase transfer catalyst in organic synthesis." Thesis, University of East Anglia, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382847.
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Godard, Anaïs. "Nouveaux procédés verts d'oxydation de l'acide oléique." Thesis, Toulouse, INPT, 2012. http://www.theses.fr/2012INPT0155/document.
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Dans un contexte de raréfaction des ressources pétrolières et de pressions environnementales, l’industrie chimique a besoin d'innover en développant de nouvelles filières destinées à l'élaboration de bioproduits, à partir de matières premières d'origine végétale. Les acides gras insaturés obtenus à partir des huiles végétales, constituent ainsi une ressource renouvelable à fort potentiel permettant de diversifier les approvisionnements d'origine pétrolière. Notre intérêt s'est porté sur la réaction de scission oxydative d’acides gras insaturés pour conduire à des monoacides et diacides à chaînes courtes et impaires, peu ou pas disponibles à l’état naturel. Ce type de chaînes hydrocarbonées est recherché dans l’industrie, car elles possèdent des propriétés spécifiques, mais elles ne sont actuellement produites qu'à partir de ressources fossiles. L'objectif était donc de mettre au point un procédé de clivage oxydatif performant, moins onéreux et moins polluant que l’ozonolyse, le seul procédé industriel opérationnel. Les conditions oxydantes sélectionnées font appel à l’eau oxygénée en tant qu’oxydant, associée à un catalyseur de transfert de phase, sans avoir recours à un solvant organique. Plusieurs catalyseurs de transfert de phase Q3{PO4[WO(O2)2]4} ont été préparés à partir de l’acide tungstophosphorique, d’eau oxygénée et d'un sel d’ammonium quaternaire (Q+,Cl-), afin de comparer leur efficacité à transférer l'oxygène vers le substrat en phase organique. Une optimisation des paramètres réactionnels a été effectuée avec le catalyseur le plus performant. De plus, deux protocoles ont été mis au point, pour la préparation in-situ du catalyseur et pour sa récupération en fin de réaction. Le procédé a été généralisé à des dérivés d’acides gras dans le but d’obtenir d'autres acides à chaînes courtes, répondant à une large gamme d'applications. Le gain environnemental lié à ce nouveau procédé a été évalué par le calcul d’indicateurs verts. Afin d’envisager un recyclage plus aisé du catalyseur, l’anion oxodiperoxotungstate {PO4[WO(O2)2]4}3-, l’espèce active du catalyseur, a été supporté sur des résines échangeuses d’anions. Deux types de résines macroporeuses ont été testées : des résines commerciales (Amberlite IRA 900 et Lewatit K7367) et des résines modifiées (type Merrifield). Nous avons montré que ces dernières conduisent à de meilleurs rendements de scission oxydative de l’acide oléique que les résines commerciales, et ce, malgré la présence de solvants. Cependant, l’immobilisation de l’anion oxodiperoxotungstate sur les résines commerciales a permis la synthèse en une seule étape d’acétals, composés présentant un grand intérêt pour la synthèse de dérivés à haute valeur ajoutée. En utilisant l’acétone, à la fois comme réactif et solvant, nous avons obtenu de bons rendements en cétal. De plus, la réaction d’acétalisation « one-pot » de l’acide oléique a pu être étendue à d’autres solvants (alcools), offrant la possibilité de synthétiser un large panel d’acétals. Le procédé développé est particulièrement intéressant car il conduit directement à la synthèse d’acétals ou de cétals à partir d’un acide gras insaturé biosourcé, en évitant les étapes de réactions intermédiairesIn a context of scarce oil resources and environmental pressures, the chemical industry needs to innovate by developing new production chains aiming the design of bioproducts from biobased raw materials. Unsaturated fatty acids derived from vegetable oils, thus represents renewable resources with a great potential, allowing to diversify petroleum based supplies. Our interest is focused on the oxidative cleavage reaction of unsaturated fatty acids to yield mono-acids and di-acids with shorter and odd hydrocarbon chains, which are not available at a natural state. Such hydrocarbon chains are attractive for industry because they meet specific properties. But, they are currently only produced from fossil resources. Therefore, the objective was to develop an efficient method for oxidative cleavage, less expensive and less polluting than ozonolysis, the only operational industrial process. The selected oxidizing conditions employs hydrogen peroxide as oxidant, together with a phase transfer catalyst, without using an organic solvent. Several phase transfer catalysts Q3{PO4[WO(O2)2]4} were prepared from tungstophosphoric acid, hydrogen peroxide and a quaternary ammonium salt (Q+,Cl-), in order to compare their effectiveness in transferring oxygen to the substrate in the organic phase. An optimization of reaction parameters was carried out with the most performing catalyst. In addition, two protocols have been developed for the in-situ preparation of the catalyst and its recovery after reaction. The method was extended to fatty acids derivatives, in order to obtain other short chain acids, having a wide range of applications. The environmental benefits associated with this new method were evaluated by calculating green indicators. To consider an easier recycling of the catalyst, the oxodiperoxotungstate anion {PO4[WO(O2)2]4}3-, the active species of the catalyst was supported on anion-exchange resins. Two types of macroporous resins were tested: commercial resins (Amberlite IRA 900 and Lewatit K7367) and modified resins (type Merrifield). We showed that the modified resins, lead to the oxidative cleavage of oleic acid with higher yields than commercial ones, despite the presence of solvent. However, the immobilisation of the oxodiperoxtungstate anion on commercial resins allows the one-step synthesis of acetals, compounds of great interest for the synthesis of derivatives with a high added value. Using acetone as both reagent and solvent, we obtained good yields in ketal. Furthermore, the "one-pot" acetalization reaction of oleic acid was extended to other solvents (alcohols) as an opportunity to synthesize a wide range of acetals. The developed process is particularly interesting as it leads to the direct synthesis of ketal or acetals from an unsaturated fatty acid, avoiding the intermediate reaction steps
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Mills, L. S. "Synthetic approaches to the antitumour-antibiotic CC-1065 : Application of a new phase transfer catalyst to oxidation; investigation of an unexpected reaction of methoxyacetyl chloride." Thesis, University of East Anglia, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372207.
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Carter, Christabel Anne. "Asymmetric phase transfer catalysis : towards catalysts with a chiral anion." Thesis, University of Leeds, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399654.
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Wales, Michael Dean. "Membrane contact reactors for three-phase catalytic reactions." Diss., Kansas State University, 2015. http://hdl.handle.net/2097/20589.
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Doctor of PhilosophyChemical Engineering
Mary E. Rezac
Membrane contact reactors (MCRs) have been evaluated for the selective hydro-treating of model reactions; the partial hydrogenation of soybean oil (PHSO), and the conversion of lactic acid into commodity chemicals. Membranes were rendered catalytically active by depositing metal catalyst onto the polymer "skin" of an asymmetric membrane. Hydrogen was supplied to the support side of the membrane and permeated from the support side to the skin side, where it adsorbed directly onto the metal surface. Liquid reactant was circulated over the membrane, allowing the liquid to come into direct contact with the metal coated surface of the membrane, where the reaction occurred. Our membrane contact reactor approach replaces traditional three-phase batch slurry reactors. These traditional reactors possess inherent mass transfer limitations due to low hydrogen solubility in liquid and slow diffusion to the catalyst surface. This causes hydrogen starvation at the catalyst surface, resulting in undesirable side reactions and/or extreme operating pressures of 100 atmospheres or more. By using membrane reactors, we were able to rapidly supply hydrogen to the catalyst surface. When the PHSO is performed in a traditional slurry reactor, the aforementioned hydrogen starvation leads to a high amounts of trans-fats. Using a MCR, we were able to reduce trans-fats by over 50% for equal levels of hydrogenation. It was further demonstrated that an increase in temperature had minimal effects on trans-fat formation, while significantly increasing hydrogenation rates; allowing the system to capture higher reaction rates without adversely affecting product quality. Additionally, high temperatures favors the hydrogenation of polyenes over monoenes, leading to low amounts of saturated fats. MCRs were shown to operator at high temperatures and: (1) capture high reaction rates, (2) minimize saturated fats, and (3) minimize trans-fats. We also demonstrated lactic acid conversion into commodity chemicals using MCRs. Our results show that all MCR experiments had faster reaction rate than all of our controls, indicating that MCRs have high levels of hydrogen coverage at the catalyst. It was also demonstrated that changing reaction conditions (pressure and temperature) changed the product selectivities; giving the potential for MCRs to manipulate product selectivity.
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Paiva, Derisvaldo Rosa. "Estudos da diastereosseletividade da adição de nucleófilos ao grupo carbonila de β-cetossulfóxidos sulfanilados derivados da 1-indanona e 1-tetralona." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-18082011-092446/.
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Neste trabalho, foi proposta a preparação e redução, seguida de hidrólise oxidativa, de alguns derivados imínicos da 2-metilsulfinil-2-metilsufanil-1-tetralona e da 2-metilsulfinil-2-metilsulfanil-1-indanona. A 2-metilsulfinil-O-metil-oxima da 1-tetralona foi preparada pela oxidação da 2-metilsulfanil-O-metil-oxima. O sulfóxido assim obtido pôde ser sulfanilado empregando-se terc-butil lítio e metanotiolsulfonato de metila, resultando um único diastereoisômero que se mostrou inerte na reação de redução da função imínica com NaBH4. Tentativas de preparar a N-tosil-imina da 2-metilsulfinil-1-tetralona, por oxidação do sulfeto correspondente, não conduziram ao produto esperado, mas sim à enamina. Buscando uma rota alternativa para a preparação de derivados imínicos de sulfinil ciclanonas sulfaniladas, foram preparados β-cetossulfóxidos derivados da 1-tetralona e da 1-indanona que, após serem sulfanilados, seriam submetidos às reações com aminas aromáticas ou alifáticas. As reações de sulfanilação da 2-metilsulfinil-1-indanona e da 2-metilsulfinil-1-tetralona foram efetuadas em condições de transferência de fase, na presença dos catalisadores TEBAC ou QUIBEC. Para ambos os casos, os rendimentos de produto foram cerca de 80 %. Enquanto os dois catalisadores conduziram a resultados estereoquímicos similares para a sulfanilação da 2-metilsulfinil-1-indanona, para a 2-metilsulfinil-1-tetralona, o uso do catalisador quiral QUIBEC resultou em um aumento da diastereosseletividade da reação, no sentido da formação do diastereoisômero majoritário de configuração relativa CR,SR. Foram também efetuadas as reações de sulfanilação das duas 2-metilsulfinil ciclanonas em meio homogêneo, empregando como bases o hidróxido de lítio ou o di-isopropil amideto de magnésio. Porém, as reações das sulfinil ciclanonas sulfaniladas assim preparadas com a anilina e com a metil-amina não foram bem sucedidas. As reações de redução com boroidreto de sódio das duas sulfinil ciclanonas sulfaniladas conduziram aos respectivos álcoois em cerca de 70 % de rendimento e na forma de um único diastereoisômero, de configuração relativa SR,C-1R,C-2R, no caso do tetralol. As duas metilsulfinil ciclanonas sulfaniladas, opticamente ativas, foram preparadas em bons rendimentos, mas sob forma escalêmica, o que não permitiu o prosseguimento do estudo do curso estereoquímico da redução da carbonila de tais compostos. A reação de adição do enolato de lítio do acetato de etila à 2-metilsulfinil-2-metilsulfanil-1-indanona conduziu ao produto esperado em bom rendimento, mas com baixo excesso diastereoisomérico. Em condições análogas, a 2-metilsulfinil-2-metilsulfanil-1-tetralona mostrou-se inerte.The original proposal of this research work was to prepare imines of 2-methylsulfinyl-2-methylsulfanyl-1-tetralone and 2-methylsulfinyl-2-methylsulfanyl-1-indanone that would be subsequently reduced and submitted to oxidative hydrolysis. By oxidation of 2-methylsulfanyl-1-tetralone-O-methyloxime the corresponding sulfoxide could be prepared, and submitted to the sulfanylation reaction using tert-butyllittium/methyl methanethiolsulfonate. The resulting product was obtained as a single diastereoisomer but showed to be unreactive towards reduction using sodium borohydride In attempting to convert the 2-methylsulfanyl-1-tetralone into the corresponding sulfoxide by oxidation, the corresponding sulfinylenamine was obtained instead of the expected sulfinylimine. Searching for an alternative synthetic route to the desired imines, the required β-ketosulfoxides were prepared and sulfanylated under phase-transfer catalysis using TEBAC or QUIBEC, as catalysts. In both cases, product yield was ca. 80%. Although for the sulfanylation of 2-methylsulfinyl-1-indanone using either TEBAC or QUIBEC the same diastereoselectivity was observed, for the reaction performed with 2-methylsulfinyl-1-tetralone and QUIBEC an improved diastereoselectivity was observed, in favour of the CR,SR diastereoisomer. Analogous sulfanylation reactions were performed in homogeneous medium in the presence of lithium hydroxide or magnesium diisopropylamide acting as bases. However, the reactions of the prepared 2-metylsulfinyl-2-methylsulfanyl ciclanones with aniline or methylamine were unsuccessful. The borohydride reduction of the 2-metylsulfinyl-2-methylsulfanyl ciclanones afforded the corresponding diastereoisomerically pure alcohols in ca. 70% yield, bearing, in the case of the tetralol derivative, the SR,C-1R,C-2R relative configuration. The two optically active sulfanylated 2-methylsulfinyl ciclanones could be prepared in good yields but as a scalemic mixture that precluded further studies in order to determine the stereochemical course of the carbonyl reduction. As for the addition reaction of the ethyl acetate lithium enolate to 2-methylsulfinyl-2-methylsulfanyl-1-indanone, the expected adduct was obtained in good yield but with poor diastereoselectivity. Under the same experimental conditions, the 2-methylsulfinyl-2-methylsulfanyl-1-tetralone underwent no reaction.
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Zhang, Jiuqing. "Palladium-Imidazolium Carbene Catalyzed Heck Coupling Reactions and Synthesis of a Novel Class of Fluoroanthracenylmethyl PTC Catalysts." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd1075.pdf.
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Racz, Robert. "Use of phase transfer catalysts in emulsion polymerization." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/11128.
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Wheeler, Theresa Christy. "Phase-transfer catalysis in supercritical fluid solvents." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/9371.
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Grigoropoulou, Georgia. "Phase transfer catalysed reactions under membrane conditions." Thesis, University of York, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369329.
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Brooks, Lancelot L. "Synthesis of bromochloromethane using phase transfer catalysis." Thesis, Nelson Mandela Metropolitan University, 2011. http://hdl.handle.net/10948/d1008162.
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The synthesis of bromochloromethane (BCM) in a batch reactor, using phase transfer catalysis, was investigated. During the synthetic procedure, sodium bromide (100.0g, 0.97mol) along with an excess amount of dichloromethane (265.0g, 3.12 mol) was charged to a reactor containing benzyl triethylammonium chloride (13 mmol), dissolved in 50 ml of water. The bench scale reactions were all carried out in a Parr 4520 bench top pressure reactor coupled to a Parr 4841 temperature controller. The method produced a 50.0 percent yield of the product BCM after a reaction time of 12 to 13 hours. The main objective for this investigation was to optimize the abovementioned reaction with respect to yield and reactor throughput. Quantitative analysis of BCM was performed on a Focus Gas Chromatograph, fitted with a flame ionization detector, and a BP20 column (30m × 0,32mm ID × 0,25 mm). Delta software, version 5.0, was applied for data collection and processing. The injector and detector port were set at 250°C and 280°C, respectively. The oven temperature was set and held at 40°C for a period of 2 minutes, then gradually increased at a rate of 10°C/min to 130°C, with the final hold time set for 1 minute. An analytical method for the quantitative analysis of BCM was developed, optimized and validated. Validation of the analytical method commenced over a period of three days, and focussed the following validation parameters: Accuracy, precision, and ruggedness. Statistical evaluation of the results obtained for precision showed that the error between individual injections is less than 2 percent for each component. However, ANOVA analysis showed a significant difference between the mean response factors obtained in the three day period (p-value < 0.05). Thus we could conclude that the response factors had to be determined on each day before quantitatively analyzing samples. The accuracy of the analytical method was assessed by using the percent recovery method. Results obtained showed that a mean percent recovery of 100.18 percent was obtained for BCM, with the absolute bias = 0.0004, and the percent bias = 0.18 percent. Hence the 95 confidence intervals for the percent recovery and percent bias are given by: (Lz, Uz) = (100.56 percent percent 102.15 percent), 13 (LPB, UPB) = (0.56 percent, 2.15 percent), respectively. Since the 95 percent confidence interval for the percent recovery contains 100, or equivalently, the 95 percent confidence interval for percent bias contains 0, the assay method is considered accurate and validated for BCM. In the same manner the accuracy and percent recovery for DCM and DBM was evaluated. The method was found to be accurate and validated for DBM, however, slightly biased in determining the recovered amount of DCM. With the analytical method validated, the batch production process could be evaluated. A total of six process variables, namely reaction time, water amount, temperature, volume of the two phases, stirring rate, and catalyst concentration, were selected for the study. The effects of the individual variables were determined in the classical manner, by varying only the one of interest while keeping all others constant. The experimental data generated was fit to a quadratic response surface model. The profile plots that were obtained from this model allowed a visual representation of the effect of the six variables. The experimental results obtained showed that the reaction follows pseudo zero-order kinetics and that the rate of the reaction is directly proportional to the concentration of the catalyst. The reaction obeys the Arrhenius equation, and the relatively high activation energy of 87kJ.mol -1 signifies that the rate constant is strongly dependent on the temperature of the reaction. The results also showed that the formation of BCM is favoured by an increase in the reaction temperature, catalyst concentration, and a high organic: aqueous phase ratio. Thus the synthesis of BCM using phase transfer catalyst could be optimised, to obtain a 100 percent yield BCM, by increasing both the reaction temperature to 105°C, and the concentration of the phase transfer catalyst -benzyl triethylammonium chloride - to 5.36 mol percent. The reaction time was also reduced to 6 hours.
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Allbutt, Bryan. "Synthesis, evaluation and application of novel phase-transfer catalysts." Thesis, University of Nottingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406998.
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Milani, Michael. "Devulcanization of automobile tires via phase transfer catalysis." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/11700.
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Wainwright, Philip. "The synthesis and investigation of novel asymmetric phase-transfer catalysts." Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245019.
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Kubota, Yasushi. "Development of asymmetric phase-transfer catalysts with chiral biphenyl framework." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/144595.
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Maxey, Natalie Brimer. "Transport and Phase-Transfer Catalysis in Gas-Expanded Liquids." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10411.
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Gas-expanded liquids (GXL) are a new and benign class of liquid solvents that are intermediate in physical properties between normal liquids and supercritical fluids and therefore may offer advantages in separations, reactions, and advanced materials. Phase-transfer catalysis (PTC) is a powerful tool in chemistry that facilitates interaction and reaction between two or more species present in immiscible phases and offers the ability to eliminate the use of frequently expensive, environmentally undesirable, and difficult to remove polar, aprotic solvents. The work presented here seeks to further characterize the transport properties of GXLs and apply these new solvents to PTC systems, which could result in both greener chemistry and improved process economics.
The transport properties of GXL are characterized by the measurement of diffusivities by the Taylor-Aris dispersion method and calculation of solvent viscosity based on those measurements. The measurement of these bulk properties is part of a larger effort to probe the effect of changes in the local structure surrounding a solute on the solution behavior. The two technologies of PTC and GXL are combined when the distribution of a phase-transfer catalyst between GXL and aqueous phases is measured and compared to changes in the kinetics of a reaction performed in the same system. The results show that increased reaction rates and more efficient catalyst recovery are possible with GXL solvents.
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Fair, Barbara E. "An investigation of omega-phase catalysis." Diss., Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/30308.
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Shah, Munish. "Investigation of phase transfer catalyzed depolymerization of nylon 46." Thesis, Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/8271.
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Wright, James T. Jr. "Kinetics of the deprotonation and N-alkylation of acetanilide via phase-transfer catalysis." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/27982.
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Beynon, Christopher. "Asymmetric phase transfer catalysed Michael additions and their application in synthesis." Thesis, University of Nottingham, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588066.
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This thesis describes an investigation into organocatalysed asymmetric Michael additions and their application in synthesis. It focuses primarily on phase transfer catalysed processes, however other modes of catalysis are briefly investigated. Firstly, β-ketoesters derived from 1-indanone and l-tetralone are examined as potential Michael donors. Their addition to methyl vinyl ketone is studied, with a view to producing members of the Gibberellin family. Secondly, the use of an achiral phenoxide "co-catalyst" in conjunction with a chiral quaternary ammonium salt, derived from cinchonidine, is found to produce an effective catalytic species. It is shown to promote the addition of benzophenone glycine imines to a range of Michael acceptors in excellent levels of enantiocontrol (>90% ee). The Michael adducts are then successfully converted to their corresponding 2,5-disubstituted pyrrolidine species, with high maintenance of stereocontrol. A potential application of this co-catalyst methodology is then described in studies towards the synthesis of kaitocephalin.
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Dutton, Mark Jason. "Synthesis and application of stereogenic nitrogen-containing ammonium salts as phase-transfer catalysts." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6755/.
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The chirality of nitrogen was at the forefront of chemistry over 110 years ago. Since then it has been widely under-acknowledged as a potential chirality source in organic synthesis. This thesis demonstrates the diastereoselective formation of stereogenic nitrogen-containing ammonium salts. Over 150 compounds were synthesised and employed as phase-transfer catalysts in order to assess the chiral-at-nitrogen influence on the outcome of two common phase-transfer-catalysed reactions. Several X-ray crystal structures of single diastereoisomer chiral-at-nitrogen ammonium salts were isolated as well as the synthesis of a library of secondary and tertiary amines.
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Dimitrov, Raytchev Pascal. "Nouvelles applications des proazaphosphatranes et molécules apparentées : vers la catalyse en espace confiné et en milieu hétérogène." Thesis, Lyon, École normale supérieure, 2011. http://www.theses.fr/2011ENSL0648/document.
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Le travail qui est décrit dans ce manuscrit de thèse traite de la chimie des superbases de type proazaphosphatranes, systèmes phosphorés bicycliques très utilisés en catalyse. L’objectif des investigations qui ont été menées à été d’ouvrir de nouvelles voies d’applications de ces catalyseurs. Afin de satisfaire cet objectif, plusieurs stratégies ont été envisagées. D’une part par la mise en confinement de la structure proazaphosphatrane et l’étude de l’influence de ce confinement sur la réactivité intrinsèque du proazaphosphatrane, et d’autre part par la catalyse en conditions bi-phasiques, que ce soit à l’interface entre une phase liquide et un solide ou entre deux phases liquides non-miscibles. Les recherches se sont orientées dans un premier temps sur la synthèse et la caractérisation complète d’un proazaphosphatrane supramoléculaire, obtenu par la fonctionnalisation par un proazaphosphatrane de la cavité supramoléculaire d’un récepteur macrobicyclique. Les séparations semi-préparatives des deux énantiomères d’un intermédiaire et de la molécule phosphorée finale ont également été réalisées, séparations qui ont permis de réaliser l’attribution des configurations absolues des deux structures macrobicycliques. La synthèse d’une famille de catalyseurs de type proazaphosphatrane supportés sur silice mésoporeuse a ensuite été réalisée, suivie de sa caractérisation texturale et structurale par les procédés physico-chimiques habituels, et enfin de sa mise en application dans des réactions d’intérêts de la synthèse organique. En dernier lieu, l’exploitation de la forme acide conjuguée des proazaphosphatranes, dite forme azaphosphatrane, dans des réactions de catalyse par transfert de phase a été entreprise. Il a ainsi put être démontré leur activité en tant qu’agent de transfert dans le cadre de quatre réactions significatives de la catalyse par transfert de phase en version racémique. Ce travail de thèse s’est finalement terminé par une ouverture vers la catalyse par transfert de phase en version asymétrique, par le biais de l’utilisation d’azaphosphatranes chiraux énantiopursThe work described in this PhD thesis deals with the chemistry of proazaphosphatrane-type superbases, which are highly reactive bicyclic phosphorous systems largely applied in catalysis. The main goal of these investigations was to devise new applications for their use in catalysis. In this way, several strategies were followed, with an emphasis on their molecular confinement and use in interfacial catalytic systems. In the first part, the manuscript describes the synthesis and characterisation of a supramolecular proazaphosphatrane obtained via the enclosing of a proazaphosphatrane moiety in a hemicryptophane-type macrobicyclic cavity. In parallel, the semi-preparative scale resolution of two macrobicyclic intermediates allowed us to assign their absolute configurations. In the second part, the synthesis and characterisation of a new class of superbases supported on mesoporous silica was achieved. The synthesis was followed by their application in base-catalysed organic reactions. The last part reports the use of their conjugate acids, or azaphosphatranes, in phase transfer catalysis. Their usefulness as achiral phase transfer agents in four relevant reactions was thus determined. The thesis ends with an introduction into asymmetric phase transfer catalysis, using enantiopure azaphosphatranes
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Kumano, Takeshi. "Enantioselective Synthesis of Cyclic α-Amino Acids through Asymmetric Phase-Transfer Catalysis." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/179375.
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Vidal, Jose Antonio. "Partially fluorinated crown ether derivatives : synthesis, phase transfer catalysis and recycling studies." Thesis, University of Leicester, 2007. http://hdl.handle.net/2381/29999.
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A series of N,N'-dialkyl-4,13-diaza-18-crown-6 derivatives containing C8H17 [2.6], (CH2) 3C8F17 (2.36), (CH2) 3C10F21 [2.37], and (CH2) 2C8F17 [2.19] sidearms were synthesized in good yields by N-alkylation of 4, 1-diaza-18-crown-6 [ 2.7]. Potassium picrate could be extracted form an aqueous solution into an organic phase by all of the perfluoroalkylated macrocycles demonstrating their potential to be used as phase transfer catalysts. They each gave higher catalytic activities under solid-liquid than under liquid-liquid phase-transfer conditions. The light fluorous macrocycles gave similar, if not better, catalytic activity compared to the present, non-fluorinated phase-transfer catalyst [2.6] under solid-liquid conditions in conventional organic solvents in both an aliphatic and an aromatic nucleophilic substitution. N,N' -Bis(1H,1H,2H,2 H,3H,3H-perfluoro-undecyl)-4,13-diaza-18-crown-6 [2.36] was recycled six times in the iodide displacement reaction of 1-bromooctane and four times in the fluoride displacement reaction of 2,4-dinitrochlorobenzene using fluorous solid-phase extraction without any loss in activity.;A series of functionalized dibenzo-18-crown-6 derivatives possessing C7H15 [4.17], (CH2)2C 6F13 [4.26], (CH2)2C 8F17 [4.27], NHC17F15 [4.31a-b], and NHCH2C6F13 [ 4.35a-b] sidearms were synthesized following different approaches. All of the non-fluorinated and partially-fluorinated dibenzo-18-crown-6 derivatives showed their potential to act as phase transfer catalysts by extracting potassium and sodium picrate from an aqueous solution into dichloromethane. By adding perfluoroalkyl sidearms to a dibenzo-18-crown-6 type structure, [4.26 ] and [4.27], the phase transfer catalytic activity was improved significantly. Bis(1H,1 H,2H,2H-perfluorooctyl)dibenzo-18-crown-6 [4.26] was recycled four times in the iodide displacement reaction of 1-bromooctane using supported fluorous phase catalysis and four times in the fluoride displacement reaction of 2,4-dinitrochlorobenzene using fluorous solid-phase extraction without any loss in activity.
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Wyatt, Victor T. "Kinetics of the solid-liquid phase-transfer catalyzed deprotonation and N-alkylation of acetanilide." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/27079.
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Tavener, Stewart J. "The preparation and use of free and supported tetraarylphosphonium salts as phase transfer catalysts." Thesis, University of York, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319452.
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Black, Elzie Dewayne. "An investigation of a novel phase transfer system - the Omega Phase : the synthesis and [4&2] cycloaddition reactions of chiral 2-phenylpropanthial." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/27308.
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Wilson, Bruce. "An experimental investigation of phase transfer catalysis in a batch oscillatory baffled reactor." Thesis, Heriot-Watt University, 2003. http://hdl.handle.net/10399/379.
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Liu, Jing. "Synthesis of resveratrol and its analogs, phase-transfer catalyzed asymmetric glycolate aldol reactions, and total synthesis of 8,9-methylamido-geldanamycin /." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1998.pdf.
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Lamb, Alan David. "Asymmetric synthesis of heterocycles via cation-directed cyclizations and rearrangements." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:4c0cf06c-d461-42a4-b4d8-a2a2bd961435.
Full textAbstract:
The aim of this project was to utilize chiral cation-directed catalysis in the asymmetric synthesis of novel hererocycles. This goal was initially realized by the synthesis of azaindolines in high yields and enantioselectivities (Chapter 2). Extension of this methodology to substrates bearing two stereogenic centres was successful, although control over both diastereoselectivity and enantioselectivity in this process was modest. Finally the synthesis of heterocycles utilizing cation-directed rearrangement processes was examined, with proof of concept obtained for a novel asymmetric cyclization to form xanthenes.
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Liou, Yu-Mei, and 劉玉美. "Inverse Phase Transfer Catalyst." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/75389230434267743351.
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Tsai, Yi-Kuei, and 蔡亦逵. "Solid-Liquid-Liquid Phase-Transfer Catalysis with a Catalyst-rich Liquid Phase - Synthesis of Hexyl Acetate." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/03574891970149176496.
Full textAbstract:
碩士國立成功大學
化學工程學系碩博士班
94
This thesis presents the results of a continued study on the novel solid-liquid-liquid phase transfer catalysis (SLL PTC), which is adopted for synthesizing n-hexyl acetate (ROAc) from n-hexyl bromide (RBr) and sodium acetate (NaOAc) by using a catalyst-rich liquid phase. The SLL PTC system contains a solid phase (NaOAc), two liquid phases (catalyst-rich liquid phase and organic phase). The phase transfer catalyst used is tetrabutylammonium bromide (QBr). The conditions for forming a solid-liquid-liquid system and the optimal conditions for the esterification of RBr and NaOAc were searched and analyzed. The operating method for reusing the catalyst-rich liquid phase was also improved. Besides, the phase change in the system containing the catalyst-rich liquid phase and organic phase was experimentally observed. This thesis is mainly divided into four parts. In the first part, the proper conditions to form a solid-liquid-liquid system were searched, the distributions of the organic reactant(RBr) and product(ROAc) between the organic phase and catalyst-rich liquid phase were measured and the effects of the amounts of NaOAc and NaBr in the catalyst-rich liquid phase and the kinds of organic solvents were investigated. The hold-up of organic solvent in the system containing organic phase and catalyst-rich-phase was measured in the second part in order to know when the phase change happened. In the third part, the sampling method was evaluated first, then the effects of the amounts of NaOAc, RBr, QBr and organic solvent, and the kinds of catalysts on the conversion of RBr were investigated to find the optimal operating conditions. The final part dealt with the subject of reusing the catalyst-rich-phase, the best way for reusing the catalyst was found. Because the main reaction occurred in the catalyst-rich phase, the reaction rate depended on the formation rate of Q+OAc-. A small amount of water should be added into the SLL PTC system for dissolving NaOAc. However, the amount of NaOAc dissolved was limited because only a limited amount of water could be added. When 25 mL of heptane was used as the organic solvent, the optimal amount of QBr and NaOAc added were 0.03 and 0.04 mol, respectively. Using an organic solvent with lower polarity and tetrabutyl ammounium bromide as a catalyst were beneficial for the formation of a catalyst-rich phase. Because the volume of organic phase is much larger than the catalyst-rich liquid phase, the organic phase is always a continuous phase and the catalyst-rich phase is a dispersed phase. In the experiments of reusing the catalyst-rich liquid phase, the conversion of RBr was found decreasing with the times of reuse. This fact was caused by the following three reasons :(1) NaBr formed during the reaction decreased the amount of ion pair of Q+OAc- resides in the catalyst-rich liquid phase. However, adding a proper amount of water is helpful for mitigating the NaBr effect. (2) Because a small of RBr stayed in the catalyst-rich liquid phase after removing the organic phase, an error in the calculated conversion was thus induced. (3) The increase in the volume of the catalyst-rich liquid phase with the times of reuse would cause the decrease in the concentration of Q+OAc- in the catalyst-rich phase, hence resulted in the decline of conversion in the 2nd and 3rd runs. To improve the above-mentioned drawbacks and error induced, the following techniques can be adopted. (1) The use of anion exchange resin for exchanging Br- in NaBr with OAc-; (2) The addition of a proper amount of water; (3) The calculation of RBr conversion should be based on the amount of RBr actually taking part in the reaction.
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Lin, Dai-Wen, and 林岱汶. "Synthesis of 2-Phenoxyethyl Benzoate by Ultrasound-Assisted Phase-Transfer Catalysis with Dual-Site Phase-Transfer Catalyst in Tri-liquid System." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/82833234913459055388.
Full textAbstract:
碩士國立中興大學
化學工程學系所
99
In this study, 2-phenoxyethyl benzoate was synthesized from the reaction of sodium benzoate and 2-phenoxyethyl bromide via a dual-site phase-transfer catalyst, 1,4-bis(trihexylammoniomethyl)benzene dibromide (BTHAMBB), under ultrasound irradiation in a tri-liquid batch system. The catalyst BTHAMBB was synthesized from the reaction of p-xylylene dibromide and excess trihexylamine in acetonitrile at 70 ℃. In this study, the investigations included the forming condition of the third-liquid phase by BTHAMBB and kinetics of synthesizing 2-phenoxyethyl benzoate. The operating parameters of forming the third-liquid phase included the amounts of catalyst and sodium benzoate, types of organic solvent, amounts of water and organic solvent, and temperature. In the conditions of 0.003 mol of sodium benzoate and 0.0015 mol of BTHAMBB in 10 cm3 of de-ionized water, 10 cm3 of toluene, temperature at 60 ℃ and stirring speed at 250 rpm, a volume 2 cm3 of the third-liquid phase was formed after 20 min of reaction without adding any extra inorganic salt in the aqueous phase. This phenomenon is due to the structure of the catalytic intermediate that made the third-liquid phase having low solubility in both water and toluene. The catalytic intermediate had the highest amount (0.00135mol) in the third-liquid phase under the molar ratio of sodium benzoate to BTHAMBB being 2:1. An excess addition of BTHAMBB might transfer more catalyst into the third-liquid phase and reduced the effective concentration of the catalytic intermediate for reaction. In this study, the third-liquid phase could be formed by using toluene and heptane as the organic solvent with the volume of 2.2 cm3 and 2 cm3, respectively. But the high-polarity solvent chlorobenzene can not be used to form the third-liquid phase, because the catalyst and the catalytic intermediate can be dissolved by chlorobenzene. The effect of temperature influenced the amount of catalytic intermediate in the third-liquid phase . The amount of catalytic intermediate, 0.00141 mol, at 80 ℃ was higher than that, 0.00112mol, at 50 ℃. In the kinetic part, the result indicated the reactions dominate to conduct in the third-liquid phase. The rate of apparent reaction could be described by pseudo-frist-order kinetic equation. The yield of the product of 2-phenoxyethyl benzoate in the organic phase was obtained 72.7 % by using BTHAMBB as the PTC in 4 h at the reaction condition of temperature at 60 ℃ , agitation speed at 300 rpm, ultrasonic frequency and power at 28 kHz and 300 W, while the yield of the product was obtained only 2 % at the same reaction condition without using BTHAMBB as the PTC. The reaction rate was not affected by stirring speed greater than 300 rpm and the kinetics was controlled by the chemical reaction. In the effect of ultrasonic irradiation, the rate of reaction increased and kapp increased 25 % as 28kHz ultrasound was applied in the reaction system. The efficiency of sonication at lower temperature, 45 ℃, was greater than that at higher temperature, 60 ℃, kapp increased 91.7 %. The fewer energy would be got in the reaction system and more energy was lost in the transport process at higher ultrasonic frequency, resulting in a lower reaction rate in this study.
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Chu, Wei-Ming, and 朱韋名. "Synthesis of Benzyl 4-Hydroxybenzoate by Ultrasound-Assisted Phase-Transfer Catalysis with Dual-Site Phase-Transfer Catalyst in Solid-liquid System." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/20861639339983499694.
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Chi, Tsung-yi, and 紀宗邑. "Phase Transfer Characteristics of Tri-Liquid-Phase Systems with Tetrabutylphosphonium Bromide as Catalyst." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/80082380318630508611.
Full textAbstract:
碩士國立成功大學
化學工程學系碩博士班
95
Recently many researches have been dedicated to the phase transfer catalysis reaction systems. In some of these systems, the formation of the third liquid phase（TLP） dramatically accelerates the reaction rate and simplifies the separation process. Studies on this field will be of great potential in the industry. Dispersion characteristics of these systems involving two or three immiscible liquids are also very important for the design of chemical processes. The stability of the system is of much importance in the design of chemical processes. Increasing the volume fraction of the dispersed phase will result in the increase of the mass transfer areas, promote the drop coalescence rate and eventually lead to the occurrence of phase inversion, i.e. the dispersed phase becomes the continuous phase and vice versa.In the past, quaternary ammonium salts have been used in the majority of reports on phase transfer catalysis reactions or third liquid systems, but it may undergo decomposition reaction under some extreme conditions of high temperatures or concentrated bases, like Hofmann degradation. Under the same reaction conditions, quaternary phosphonium salts can be equally effective and more stable.Thus, we use tetrabutylphosphonium bromide as catalyst to catalyze the synthesis of phenyl benzoate from benzoyl chloride in the organic phase and sodium phenolate in the water phase. In this text, the method of electrical conductivity was used to investigate the effect of concentrations of the PTC and reactants upon the phase transfer characteristics of the TLP systems, volume of the TLP, droplet coalescence time and the delayed inversion time. We found that in the systems with higher concenrations of PTC, no matter for W/O -> O/W or O/W -> W/O, phase inversion Hold-Up would decrease with increasing contentrations of PTC and stirrer speeds. Phase inversion hold-up would decrease with increasing concentrations of water phase reactant, but it become reverse for the increasing concentrations of organic phase reactant. Besides, phase inversion hold-up of the systems decrease with increasing concentrations of the both phase reactants. For the factors which affect the formation of the third liquid phase, the amount of the TLP formed increaes with increasing concentrations of PTC and both phases reactants. We also found that stirrer speed affected the amount of the TLP formed and TlP were easier to be formed under higher stirrer speeds. In addition, the formation of the TLP also have relations with the composition of the system. For the systems with NaOH added, the amount of TLP formed changes inconsistently with increasing amounts of NaOH. In such systems, phase inversion hold-up decrease slightly. In general, the Tc values of the systems contain the TLP or NaOH are higher than those of the other systems. For the most systems, the Tc values of the O/W dispersion type are higher than those of the W/O dispersion type.
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郭士銘. "Synthesis of N-Butyl Phenyl Ether by Tri-Liguid-Phase Catalysis Using Polyethylene Glycol-600 as Phase Transfer Catalyst." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/29680272994216088872.
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碩士國立成功大學
化學工程學系
87
In a study on the reaction between n-butyl bromide (BuBr) and sodium phenolate (NaOPh) with quaternary ammonium salts as the phase transfer catalyst, we found that a third liquid phase appeared when the solubility of catalyst in both of aqueous phase and organic phase are poor, catalyst will be gathered between aqueous phase and organic phase and formed a third liquid phase. The appearance of the third liquid phase not only can increase the reaction rate but also provides the chance for reusing the catalyst simply by the reuse of itself. The purpose of the present research is to investigate the possibility to replace quaternary ammonium salts with polyethylene glycols-600 (PEG-600), which is cheap and non-toxic, to form the third liquid phase. The conditions for forming a third liquid phase and the effect of the third liquid phase on the reaction were investigated. Besides, the discrepancy of quaternary salts and polyethylene glycols-600 on forming the third liquid phase was also compared. This dissertation is divided into two parts. The first part reports the results of the experiments in exploring the conditions for forming a third liquid phase and investigating the factors influencing the characteristic of the third liquid phase. The second part presents the experimental results of the reaction between n-butyl bromide and sodium phenolate conducted under the conditions determined by referring the result obtained in the first part. By way of observing the effects of the third liquid phase in a batch reactor on the reaction rate and the fractional yield, the formation of the third liquid phase can be understood further. In the investigation on the formation of a third liquid phase, we found that the total added amount and the individual mole fraction of NaOPh and QBr added, kinds of organic solvent, operating temperature, kinds of PEG, and kinds and amount of salt were the important influencing factors. We also found that the system using PEG-600 as the phase transfer catalyst without adding hard base (e.g., NaOH) would not generate a third liquid phase. The formation of a third liquid phase for PEG is due to that the hydrophilic groups PEG associate with cations, in addition to that the water molecules in the aqueous phase are attracted by OH- ions, hence there are not enough hydrogen bonds to maintain hydrophilic of PEG. From experimental results of the second part, we find that PEG with a high molecular weight or a long chain does not facilitate a high reaction rate and there exits an optimal molecular weight. In this study, PEG-600 provides the best result. In general, a high concentration of catalyst in the third liquid phase would favor the reaction rate. So using a non-polar organic solvent, a high concentration of NaOH and a high reaction temperature would increase the conversion.
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Lin, Hsiang-Yi, and 林湘漪. "Synthesis of Benzyl Triphenylphosphonium Phenoxide and Use as Phase Transfer Catalyst." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/02039657909664375618.
Full textAbstract:
碩士東海大學
化學工程學系
91
In this work, the primary purpose of this work is to use quaternary phosphonium salt as phase transfer catalyst to synthesize ether compounds in an organic solvent / aqueous solution two-phase medium. This thesis is classified into two parts： （a）Synthesizing and identifying phase transfer catalyst, benzyl triphenyl phosphonium chloride ( BTPPC ) and benzyl triphenyl phosphonium phenoxide（PhOQ）. （b）Synthesizing and studying the kinetic behavior of ether compounds. The synthesized quaternary phosphonium salt is an effective phase transfer catalyst. BTPPC dissolvs in aqueous phase easily and the product PhOQ which is produced from the reaction of sodium phenoxide and BTPPC transfers to organic phase quickly. Then, PhOQ further reacts with organic phase reactant in organic phase to produce the desired ether compounds. For simplifying kinetic model, we assume that the organic phase reaction is the rate determining step. A pseudo first-order rate law is successfully applied to represent the reaction. From the experiment result, the biggest advantages of using quaternary phosphonium salt as phase transfer catalyst, are fast reaction rate, lower reaction temperature, high selectivity…etc. .
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Chen, Wen-Ke, and 陳文科. "Phase Transfer Characteristics of PTC System with Tetrabutylphosphonium romide as Catalyst." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/23672593161127468125.
Full textAbstract:
碩士國立成功大學
化學工程學系碩博士班
91
For an immiscible two-phase system, the chemical reactions occur only in the interface, hence the reaction rate is very slow and the yield is low. If phase-transfer catalyst (PTC) was added, it could transport the reactants between the water phase and the organic phase. It was found that the reaction rate could be greatly enhanced. In addition, phase-transfer catalysis has many merits such as small amounts of catalyst, mild conditions for the chemical reactions, greater reaction rate, higher yield and selectivity. Consequently, the researches of phase-transfer catalysis are the emphasis of chemical engineering industries. On the other hand, for the system with two immiscible phases, characteristics of phase-inversion are the major concerns from the view point of the stability of tsystem. The dispersion characteristics embrace the dynamic behaviors of the continuous phase and the dispersion phase in the system, hold up and droplet size of the dispersion phase, and the conditions which may cause the phase-inversion. Phase-inversion refers to the phenomenon that an agitated emulsion of oil droplets in water (O/W) changes its type immediately, and becomes an emulsion of water droplets in oil (W/O), and vice versa. These characteristics of phase-inversion will affect the reaction rate of the system. In general, quaternary ammonium salts have been used in the majority of reported phase-transfer reactions and dissertations, but quaternary phosphonium salts can be equally effective, and may be preferred under some extreme conditions of high temperature or concentrated base when Hofmann Degradation occur. As the result, quaternary phosphonium salts have specific value in the industrial applications. In this thesis, we use the synthesis of phenyl benzoate from benzoyl choride in the organic phase and sodium phenolate in the water phase with tetrabutylphosphonium bromide as the catalyst to study the variations of the physical properties, characteristics of phase-inversion and delayed inversion time of the systems upon changing the PTC concentrations and reactant concentrations. In the systems which PTC added only, we found that it tends to help water becoming continuous phase when agitated speed increased, i.e. it tends to form an O/W emulsion. Therefore, the occurrence of O/W→W/O is more difficult. In this test, the results of the physical properties, characteristics of phase-inversion, droplet coalescence time and delayed inversion time of systems are similar to those obtained by using quaternary ammonium salts. Comparatively speaking, the hold up of phase-inversion of systems with tetrabutylphosphonium bromide added is higher than those with quaternary ammonium salts or inverse phase-transfer catalyst added. It shows that it is easier to form an O/W emulsion after quaternary phosphonium salts are added. With regard to those systems which mass transfer or chemical reaction occur, the increasing of the reactant concentrations tends to increase the hold up of the W/O→O/W type phase-inversion. However, the dispersion characteristics become more complicated with higher concentrations of the reactants, we found that the phase-inversion hold up decrease at higher concentrations. In the O/W→W/O type, we could not observe the happening of phase-inversion for the most parts of the experiments. For the coalescing time of droplets, when the reactant concentrations or agitated speed is increased, the dispersion of O/W type is stable and higher Tc value could be obtained. For the systems which the phase-inversion could be observe, the value of Tc of the W/O→O/W type are always larger than O/W→W/O type. For the delayed inversion time, the larger the hold up of phase-inversion is, the smaller the Td value. Systems which accompany with mass transfer or chemical reaction, for the O/W→W/O type system, in some cases, in spite of the happening of phase-inversion, nevertheless, it reversed from W/O to O/W.
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Naicker, Serina. "An investigation into air stable analogues of Wilkinson's catalyst." Thesis, 2010. http://hdl.handle.net/10413/10765.
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Since the discovery of Wilkinson’s catalyst and its usefulness in the homogeneous hydrogenation of olefins many investigations have been carried out on trivalent, tertiary phosphine–rhodium complexes.¹ Studies have shown that N-Heterocyclic carbenes as ligands offer increased stability to the complex and possess similar electronic properties as phosphine ligands.² The applications of the traditional catalyst are limited due to the limited stability of its solutions and its susceptibility to attack from the environment i.e. oxygen and moisture. The hydrogenation of olefins and other unsaturated compound is of great importance for the fine chemical and petroleum industries. The aim is to produce more stable and active versions of the traditional catalyst and also to demonstrate their improved stability and activity in catalytic applications. This study involves the investigation of the effects of ligand modification on Wilkinson type hydrogenation catalysts. Five Rhodium-phosphine complexes 1a: Rh(PPh₃)₃Cl, 1b: Rh(PPh₂Me)₃Cl, 1c: Rh(PPh₂Et)₃Cl, 1d: Rh(PPhMe₂)₃Cl, 1e: Rh(PPhMe₂)₃Cl have been synthesised and characterised by means of melting point,¹H NMR, ¹³C NMR, ³¹P NMR, IR and Mass Spectroscopy. Complexes 1d and 1e have also been characterised by means of elemental analysis and single crystal XRD. Five rhodium-N-heterocyclic carbene complexes 2a: Rh(COD)ImesCl [Imes =1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene] , 2b: Rh(COD)(diisopropylphenyl)₂Cl 2c: Rh(COD)(adamantyl)²Cl, 2d: Rh(COD)(diisopropyl)²Cl 2e: Rh(COD)(ditertbutyl)²Cl have been synthesised and characterised by means of melting point, ¹H NMR, ¹³C NMR, IR and Mass Spectroscopy. Five rhodium-NHC-CO complexes 3a: Rh(CO)₂ImesCl, 3b: Rh(CO)₂(diisopropylphenyl)₂Cl, 3c: Rh(CO)₂(adamantyl)₂Cl , 3d: Rh(CO)₂(diisopropyl)₂Cl, 3e: Rh(CO)₂(ditertbutyl)₂Cl, have been synthesised and characterised by means of ¹H NMR, ¹³C NMR, IR and Mass Spectroscopy.
Complexes 1a, 1d, 1e, 2a, 2b, 2c, 2d, 2e were tested in the hydrogenation of simple alkenes under mild conditions. For the rhodium-phosphine complexes the catalyst efficiency based on TOF increases in the following order: 1a > 1d > 1e or RhCl₃(PPhMe₂)₃ > RhCl₃(PPhEt₂)₃ > RhCl(PPh₃)₃. For the rhodium-(COD)-NHC complexes catalyst efficiency based on TOF increases in the following order: 2d > 2b > 2e > 2a > 2c. While rhodium-phosphine complexes are far more active than rhodium-(COD)-NHC complexes, the latter seem to be active for a longer time and hence more stable under mild hydrogenation conditions.Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2010.
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Aggarwal, Ravi. "Supported Aqueous-Phase Catalysis for Atom Transfer Radical Polymerization." 2010. http://trace.tennessee.edu/utk_graddiss/771.
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Atom transfer radical polymerization (ATRP) which utilizes transition metal based catalysts is a versatile methodology for the synthesis of a wide spectrum of polymers with controlled architectures. However, high concentrations of soluble catalyst required in an ATRP process makes the final polymer colored and toxic. Thus, the catalyst removal/reduction/recycling remains a challenge in the field of ATRP.
Supported catalysts on insoluble solids such as silica gel, polystyrene beads, etc. have been used in ATRP to facilitate the catalyst recovery and recycling. However, the ability of the supported catalysts to mediate a polymerization is substantially reduced due to their reduced mobility and leaching problems.
In this thesis, we report a series of novel and recyclable physisorbed CuBr2/N, N, N’, N’’-pentamethyldiethylene-triamine supported catalytic systems operating in conjunction with hydration. Supported aqueous-phase catalysis (SAPC) for ATRP was evaluated for different inorganic (Na-clay, silica and zeolite) and organic (polysaccharides) supports. The hydrated physisorbed supported catalysts were used for the polymerization of benzyl methacrylate and methyl methacrylate using an activator generated electron transfer ATRP process.
The catalyst was effectively retained on the surface of supports through hydration as was verified by UV-Vis measurements. The supported catalyst was easily removed from the polymerization by simple filtration process affording a colorless polymer solution. The polymerizations produced high conversion and colorless polymers with moderately narrow polydispersity indices (PDI). The catalyst maintained high activity during the recycling experiments.
We also investigated the kinetic and mechanistic behavior of these solid supported polymerization systems. Based on split kinetics experiments and UV-Vis studies it was believed that the activation and deactivation processes took place at the diffused hydrated interface between the solid support and organic phase.
The branched (stars and graft) polymers were also synthesized using Na-clay supported catalyst. The produced polymers had narrow PDI and good initiator efficiencies. The functionality of the star polymers was confirmed using 1H NMR and dilute solution properties. The synthesis of graft-copolymer was confirmed by 1H NMR and atomic force microscopy.
This thesis demonstrates the successful use of SAPC for ATRP to produce contamination free linear and branched polymers with moderately narrow PDI and high recycling efficiency.
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LI, ZHEN-HUI, and 李貞慧. "Application and syntheses of drifttype cryptand phase transfer catalyst and crown ether adsorbents." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/17563851745354024947.
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CHANG, KONG-RONG, and 張光榮. "A STUDY ON THE ALLYLATION OF PHENOXIDE USING POLYETHYLENE GLYCOLS AS PHASE TRANSFER CATALYST." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/57108057175797717002.
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Yang, Ro-Yi, and 楊若怡. "Phase Inversion Characteristics of the Synthesis of Hippuric acid Using 4 –(dimethylamino)pyridine as the Inverse Phase Transfer Catalyst." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/59788720077270750647.
Full textAbstract:
碩士國立成功大學
化學工程學系碩博士班
90
Recently many researches have been dedicated to the study of phase transfer catalytic (PTC) reaction systems. Inverse phase transfer catalyst (IPTC) is getting more and more important in this field. In view of the industrial applications, the stability of the dispersed system, involving two immiscible liquids, is of much importance in the operations. Increasing the volume fraction of the dispersed phase will result in the increase of the mass transfer areas, promote the drops coalescence rate and eventually lead to the phase inversion, i.e. the dispersed phase becomes the continuous phase and vice versa. The characteristics of phase inversion will affect the reaction rate and the liquid behavior of the system. In this study, we use the synthesis of phenyl hippuric acid from benzoyl choride (organic phase) and glycine (water phase) with 4 –dimethylaminopyridine (DMAP) as the IPTC to study the dispersion stability of this kind of systems, and to compare the results with other IPTC systems. In those systems with DMAP added , we find that it tends to help water to become the continuous phase, and when the agitated speed increases, it tends to form an O/W emulsion. The results of the physical properties、phase inversion characteristics、droplet coalescence time and delayed inversion time of the systems using DMAP are similar to those obtained by using other two IPTCs, 4 – picoline-N -oxide and pyridine-N-oxide. However, the interfacial tension is the lowest of these systems by using DMAP. In those systems with catalysts added only, the sequence of easier to form an O/W dispersion is 4 – picoline-N-oxide、4 –dimethylaminopyridine and pyridine-N-oxide. In systems with the catalyst and organic phase reactant, there is no obvious trends can be found in the phase inversion hold-up. In those systems with catalyst and two phase reactants, with the increase of the reactant concentrations it gets more and more difficult to form an O/W dispersion. These two systems mentioned before are the most easily to make the occurrence of O/W→W/O by using 4 – picoline -N-oxide at low reactant concentrations; 4 –dimethylaminopyridine at high reactant concentrations and so forth. The tendency of the decrease of the inversion hold-up(o) with the increase of the reactant concentration of the system using DMAP as the catalyst is not so significant as the other two systems; it shows that the system using DMAP is not such sensitive to the reactant concentrations than the others.
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DU, JING-SHUN, and 杜景順. "On the indirect anodic oxidation of benzyl alcohol in the presence of phase transfer catalyst." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/77428521777762841199.
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Cheng, Hui-Chun, and 鄭慧君. "Synthesis of n-Heptyl o-Hydroxybenzoate by Phase-Transfer Catalyst and Ionic Liquid in Liquid-Liquid System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/58354550142988760969.
Full textAbstract:
碩士國立中興大學
化學工程學系所
103
The study aimed at synthesizing n-heptyl o-hydroxybenzoate by using o-hydroxybenzoic acid sodium salt and 1-bromoheptane under the catalysis of phase transfer catalyst in liquid-liquid system. The operating parameters included agitation rate, ultrasonic effect, reaction temperature, type and amount of catalyst, type of solvent, type and amount of ionic liquid. The reaction mechanism and kinetics of reaction were obtained from experimental results. The esterification reaction between 1-bromoheptane and o-hydroxybenzoic acid sodium salt occurs in organic phase, and Aliquat 336 can be used to reach the highest yield among all catalysts employed in this study. Using low-polar or non-polar solvents such as toluene and heptane the yield would be lowered and indicated the influence of the level of solvent polarity on the rate. Due to the concern of green reaction, toluene was selected as the solvent, without using high polar and toxic organic solvent, methly isobutyl ketone (MIBK). In this liquid-liquid phase transfer system, the aqueous-phase reactant can be transported from aqueous-phase to organic-phase by the hydrophobic characters of catalytic Aliquat336, which thus can catalyze esterification of sodium benzoate and benzyl bromide. The experimental results showed that the more the mounts of catalyst, the faster the synthesizing reaction rate would be. Effects of different organic solvents and ionic liquids for Aliquat336 were carried out, and above 74% yield of benzyl benzoate is easily achieved within 3 hours. At 3 hours, the product yield was 0% without adding both ionic liquid and catalyst.The yield was 74.37% by adding catalyst but without ionic liquid; adding both catalyst and ionic liquid would promote yield to 77.88%. Both ultrasound and stirring assisting liquid -liquid phase-transfer catalysis could be effectively applied in synthesizing ether-ester. Pesudo-first-order kinetic equation was applied to correlate experimental results. Using toluene as solvent, the kinetic results were correlated by using -ln(1-Y)=kappt equation successfully , where kapp was the apparent reaction rate constant, with ultrasound, the apparent activation energy was 18.31 kcal/mol.
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Do, Young Long, and 杜永隆. "On the Indirect Anodic Oxidation of Benzyl Alcohol in the Presence of Phase Transfer Catalyst in CSTER." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/09032861090813950464.
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Lee, Lin-Wen, and 李玲玟. "Synthesis of Benzyl Salicylate by Dual-Site Phase Transfer Catalyst and Ionic Liquid in Tri-Liquid System." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/75337996896560910542.
Full textAbstract:
碩士國立中興大學
化學工程學系所
100
The present study was to investgate esterification of sodium salicylate (Ph(OH)COONa) and benzyl bromide (RBr) to synthesize benzyl salicylate by dual-site phase transfer catalyst and ionic liquid in tri-liquid system. The novel dual-site phase transfer catalyst, 4,4’-bis tri(proplyammoniomethyl)- 1,1’-biphenyl dichloride (BTPAMBC, QCl2) was synthesized from the reaction of 4,4’-bis(chloromethyl)-1,1’-bisphenyl and tripropylamine. The operating parameters of forming the third-liquid phase included the amounts of catalyst,salt and water, types of reactant, organic solvent and salt,and temperature.The results indicated that the third-liquid phase had higher quantity Q2+ under the molar ratio of Ph(OH)COONa to BTPAMBC being 4:1.The solution containing the same bromide ion could result in the common-ion effect, which made third liquid phase become solid. Using NaCl could avoid the common-ion effect, and the tri-phase had highest Q2+ when adding 0.05 mole of NaCl. Both high polarity solvent,MIBK, and low polarity solvent, toluene, were used to form the third liquid phase, and the volumn were 0.8 cm3. However, Q2+ was distributed in MIBK phase but no Q2+ observed in the toluene phase. Using n-heptane as the solvent, the volumn of tri-phase was 1cm3 and had most Q2+ in tri-phase. In the system, the temperature effect influenced the amount of catalytic intermediate and composition of third liquid phase, the amount of catalytic intermediate,0.426 mmol, at 30°C, 0.648 mmol, at 60°C; the volume of third liquid phase,0.8 cm3, at 30°C, 1 cm3, at 60°C. In the kinetic part, the result indicated the reactions dominate to conduct in the tri-phase. When compared with commercial catalysts, BTPAMBC had better catalytic efficiency. At 30 min, the product yield was 0.21% without adding both ionic liquid and catalyst. The yield was 51.55% by adding BTPAMBC but without ionic liquid, and was 96.88% using both ionic liquid and BTPAMBC. With different structures of ionic liquids the catalytic efficiency was significantly enhanced. Stirring at 350 rpm, mass transfer resistance had not a significant effect on the reaction rate. Using n-heptane as the solvent, the kinetic results were correlated by using -ln(1-Y) =kappt equation successfully, where was the apparent reaction rate constant, and the apparent activation energy was 18.78 kcal/mol with high efficiency.
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Chuang, Fu-Chun, and 莊富鈞. "Synthesis of n-Heptyl 4-Hydroxybenzoate by Phase-Transfer Catalyst and Ionic Liquid in Liquid-Liquid System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/34039778106917644588.
Full textAbstract:
碩士國立中興大學
化學工程學系所
102
The study aimed at synthesizing n-heptyl 4-hydroxybenzoate by using 4-hydroxybenzoic acid sodium salt and 1-bromoheptane under the catalysis of phase transfer catalyst in liquid-liquid system. In addition to reactants, the operating parameters in the reaction system include agitation rate, ultrasonic effect, reaction temperature, type and amount of catalyst, type of solvent, type and amount of ionic liquid. The reaction mechanism and kinetics of reaction were obtained from experimental results. The esterification reaction Between 1-bromoheptane and 4-hydroxybenzoic acid sodium salt occurs in organic phase, and using Aliquat 336 can reach the highest yield among all catalysts employed in this study. Because Aliquat 336 is oil-soluble, n-heptane could be selected without using high polar and toxic organic solvent, methly isobutyl ketone (MIBK). In general, there is an induction period in the beginning of reaction due to the catalyst solubility. Ionic liquid can be added to overcome this problem and reduce the reaction time. The experimental result shows that activation energy Ea= 6.19 kcal/mol by Arrhenius equation. Adding more organic phase reactant can further improve the reaction rate. The result shows that after reacting 3 hours, the yield is 54% by using Aliquat 336, and the reaction temperature is only 60℃, the non-toxic organic solvents can be used. Instead of using strong acid and alkali as catalyst and toxic organic solvents. The system that needs high reaction temperature also can be improved. By doing so, we can reduce the production cost and danger as well.