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Showing 1 to 10 of 10 for “"Brønsted Acids"”.
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Asymmetric Catalysis with Brønsted Acids: Experiments and Calculations
… on enantioselective catalysis using BINOL-based Brønsted acids. The initial part of this work comprises the development of chiral phosphoric acids and N-triflylphosphoramides having alternative groups at the 3,3’- positions, different from the widely common aryl scaffolds. These motifs include …
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Charge-Enhanced Brønsted Acids: Catalyst Designs and Analytical Methods
… As a result, charged hydrogen bond donors and Brønsted acids have been synthesized and are more effective catalysts in nonpolar media compared to their neutral analogues. In this dissertation, this charge enhanced effect is examined through a structure-reactivity relationship and new …
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Influence of oxygen vacancies on oxygenate reactions over SnO₂(110) single crystal surfaces
The adsorption of a number of Brønsted acids of differing strengths has been studied on stoichiometric and defective Sn0₂ (110) surfaces. The extent of dissociation of these acids depends on the surface composition and the strength of the acid. Two crystallographically inequivalent types of oxygen …
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Enantioselective [4 + 2] cycloadditions of iminoacetonitriles : application to the total synthesis of (-)-quinolizidine 2071
… Diels- Alder cycloadditions promoted by chiral Brønsted acids as well as the discovery that iminoacetonitriles can also participate in acid catalyzed cycloadditions. The second part of this thesis reports the total synthesis of (-)-quinolizidine 2071 using an intramolecular, enantioselective …
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Electrostatically Enhanced Phosphoric Acids and Their Applications in Brønsted Acid Catalysis
Different types of Brønsted acid catalysts are commonly used in a wide variety of organic transformations and are of continuing interest because there is a general need to carry out reactions in a faster and higher yielding manner with greater selectivities. Phosphoric acid derivatives, with their …
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Brønsted Acid Catalyzed Carbon-Carbon Bond Forming Reactions
… development of new methodology in the field of Brønsted acid catalysis enabling rapid synthesis of medicinally relevant compounds. It is foreseen that small molecule sulfonic acids evaluated in this research project will unveil new asymmetric carbon carbon bond forming reactions between …
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Catalytic conversion of biomass-derived molecules into mono- and dicarboxylic acids and esters
… of fuels and chemicals. Mono- and dicarboxylic acids and esters are key intermediates to chemical products, especially for biodegradable polymers. This thesis has addressed the challenges in chemocatalytic synthesis of mono- and dicarboxylic acids and esters, including gluconic acid, succinic …
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Mechanism and application of Lewis and Brønsted acid effects in organotransition metal catalysis
… of a transition metal, Lewis acid, and Brønsted acid. Chapter 1 reviews the literature regarding the cooperativity of transition metal and Lewis acid catalysis, and discusses four main areas in organic synthesis and the facilitation of these trnasformations by Lewis acids: (a) C-C bond …
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Exploration of Carbon-oxygen and Carbon-nitrogen Bond Formation Utilizing Trichloroacetimidates and Investigations of New Reactions Mediated By Oxoammonium Salts
… is observed with other conditions using Lewis or Brønsted acids. These reactions have been broadened to benzyl esters without electron donating groups on the benzylic ring. The trichloroacetimidates therefore provide inexpensive and convenient methods that should find use in the formation of …
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Síntesis de indoles y carbazoles funcionalizados: catálisis con complejos de Au(III) y ácidos de Brønsted
… en Síntesis Orgánica utilizando ácidos de Brønsted y complejos de oro(III) como catalizadores. El hilo conductor es el núcleo indólico, cuya funcionalización selectiva continúa siendo un objetivo relevante en Química Orgánica. Bajo catálisis con ácidos de Brønsted hemos desarrollado una …