No description available.

Thesis (M.Sc.)--York University, 2006. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 89-97). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR19645

Thesis (doctoral)--Friedrich-Alexander-Universität zu Erlangen.

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 134-147). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 216-224).

A brief overview of why it is important to prepare a chiral compound as a specific enantiomer rather than as a racemate is discussed along with several general strategies on how they maybe prepared. The area of research into the preparation of racemic and enantiomerically pure arylpropanoic acids is briefly reviewed by reference to some of the more important synthons. Some of the more general procedures that have been developed for the construction of arylpropanoic acids are discussed. The preparation of substituted alkyl aryl ketones and their subsequent two step conversion into diastereomerically enriched dimethyl tartrate (S)-bromoalkyl aryl acetals is described. An investigation into the effects of solvent, source of anhydrous acid, workup procedure, source of bromine and temperature upon the bromination of these dimethyl tartrate acetals is discussed. Direct conversion of these diastereomerically enriched dimethyl tartrate (S)-bromoalkyl aryl acetals into enantiomerically pure (S)-bromoalkyl aryl ketones and their subsequent conversion into (S)-bromoalkyl aryl esters via a Baeyer-Villiger reaction is described. Hydrolysis of these (S)-bromoalkyl aryl esters followed by treatment with diazomethane afforded the corresponding methyl (S)-bromoalkyl esters with minimal racemisation, while treatment of these (S)-bromoalkyl aryl esters with an amine gave the corresponding amide with minimal racemisation. Reduction with sodium borohydride at low temperature of a (S)-bromoalkyl aryl ketone afforded exclusively the corresponding (1S,2S) alkyl aryl bromohydrin as predicted using the Felkin-Anh model. Stereospecific conversion of our diastereomerically enriched dimethyl tartrate (S)-bromoalkyl aryl acetals into (S)-arylcarboxylic acids using a silver promoted or solvent promoted rearrangement is discussed. Subsequent conversion of these (S)-arylcarboxylic acids into the corresponding Boc amide via a modified Curtius rearrangement is described. Possible further uses of dimethyl tartrate bromoacetals leading to the synthesis of highly functionalised lactones, lactols, epoxides, chiral diacids, diamines, chiral ligands, resolving agents etc are also discussed.

L'objectif de cette thèse est de développer un outil prédictif pour calculer les équilibres vapeur-liquide (VLE) associé à l'opération d'hydrotraitement à partir de biomasse pour la simulation de processus. La construction d'une base de données de solubilité fiables d'hydrogène et d'autres gaz d'hydrotraitement ont été réalisées. Le modèle utilisé a pour base l’équation Groupe Contribution- Polar Perturbed Chain - statistique Associer Fluid Theory (GC-PPC-SAFT), qui est version de PC-SAFT combiné avec la contribution de groupes proposé par Tamouza et un terme polaire développé par Nguyen Huynh. Des tests systématiques ont été effectué pour différents mélanges gaz + d'alcools, aldéhydes, esters, éthers, cétones, ... Une nouvelle contribution non-additif a été proposé sur la base des réflexions sur les interactions répulsives et l’effet de volume libre. Le modèle a été validé notamment par des simulations Monte Carlo. Ce terme non additif a été intégré dans GC-PPC-SAFT et testé pour les systèmes contenant de l'hydrogène. La méthode de contribution de groupes a été étendue au paramètre de ce nouveau terme. Des écarts moyens sur la constante de Henry sont en accord avec l'incertitude expérimentale (~ 10%). Nous avons également examiné la prédiction d’ autres gaz i.e. CO, H₂ S, NH₃ en utilisant GC-PPC-SAFT. Un paramètre associatif transversale a été utilisé pour des systèmes contenant H₂ S et NH₃. Les résultats sont tout à fait acceptable et cohérent avec l'incertitude expérimentale (~20%). / The main objective of this thesis is to develop a predictive tool to compute the vapor-liquid equilibria (VLE) associated with hydrotreating operation from biomass for process simulation. The construction of a reliable database of hydrogen and the other hydrotreating gases solubilities have been done. The model used based on the Group Contribution – Polar Perturbed Chain – Statistical Associating Fluid Theory (GC-PPC-SAFT), which is PC-SAFT combined with the group contribution proposed by Tamouza and a polar term developed by Nguyen Huynh. The systematic tests have been perform for mixtures of alcohols, aldehydes, esters, ethers, ketones,… A new non-additive contribution has also been proposed based on the reflections on the repulsive interactions and the free volume effect. The model development are validated by Monte Carlo simulations. This non-additive term has been integrated in GC-PPC-SAFT Equation of state and tested for systems containing hydrogen. Group contribution method has been extended to its parameter. Average deviations on Henry’s constant are within the experimental uncertainty (~10%). We also have performed the prediction of the other gases i.e. CO, H₂S, NH₃ solubility using GC-PPC-SAFT. A cross associative parameter has been used for systems containing H₂S and NH₃. The results are quite acceptable and within the experimental uncertainty (~20%).

A general review on macrocyclic ligands with particular emphasis to dibenzocryptand 222 and dibenzo 18 crown 6 is given in the first part of the thesis (Chapter 1). This is followed by an exhaustive literature survey on the stability constants (hence free energies of complexing), enthalpies and entropies of metal cations with cryptands (dibenzocryptand 222, benzocryptand 222, cryptand 222) and crown ethers (dibenzo 18 crown 6, benzo 18 crown 6, 18 crown 6) in water and in non-aqueous solvents at 298.15 (Chapter 2). The experimental part (Chapter 3) also includes a detailed description of the principals involved in calorimetry as well as the methods used for the calculation of reaction enthalpies. Stability constant data for alkali-metal and silver cations with dibenzocryptand 222 in five dipolar aprotic solvents (N,N dimethyl-formamide, dimethylsulphoxide, acetonitrile, propylene carbonate and nitromethane) at 298.15 K are reported. These data are used to calculate the standard free energies of the complexation process involving metal(I) cations and dibenzocryptand 222 in the dipolar aprotic solvents. Free energy data are combined with enthalpy data obtained in this work in order to evaluate the entropies of complexation of these cations with dibenzocryptand 222 in these solvents. A linear correlation previously shown for metal(I) cations and cryptand 222 in DMF, Me2SO, AN, PC and NM between entropies of complexing and entropies of solvation of metal(I) cations in dipolar aprotic solvents is also found for dibenzocryptand 222. The results obtained in this thesis provide further evidence that the complexation process with metal (I) cations and cryptands is mainly controlled by the state of solvation of the cation in the solvent. Enthalpies of solution of dibenzocryptand 222 in the dipolar aprotic solvents are reported and the thermodynamic parameters for the extraction process in the water + nitromethane solvent system as described by M+(H2O) + 22B2B(NM) → M+22B2B (NM) are calculated (Chapter 4). Thermodynamic parameters of solution and transfer of dibenzo 18 crown 6 are discussed with respect to corresponding data for dibenzocryptand 222. The transfer free energies of metal ion dibenzocoronates from water to a number of solvents are calculated and it is shown that, unlike cryptates, there is an interaction between the complexed cation and the solvent in metal ion dibenzocoronates in dipolar aprotic media. Thermodynamic parameters of complexation for alkali-metal and dibenzo 18 crown 6 in acetonitrile are reported. The complexation process seems to be enthalpically and entropically controlled (Chapter 5). Synthesis of crown compounds and heats of solution of 18 crown 6 carried out at several temperatures as well as DeltaCp values in water are presented in Chapter 6.

No description available.

No description available.