Search for dissertations about: "Desymmetrization"
Showing result 1 - 5 of 8 swedish dissertations containing the word Desymmetrization.
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1. Controlling the Reactivity and Selectivity in Iridium- and Rhodium-Catalyzed Asymmetric Hydrogenation
Abstract : The work presented in this thesis is mainly focused on the development of iridium- or rhodium-catalyzed asymmetric hydrogenation featuring a number of practical concepts including cascade reaction, kinetic resolution, desymmetrization, and dearomatization. The protocols rely on gaining control of the reactivity among different olefins or olefin precursor as well as maintaining chemo- and stereo-selectivity in the hydrogenation. READ MORE
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2. Methods for Asymmetric Olefination Reactions; Development and Application to Natural Product Synthesis
Abstract : This thesis deals with the development and application of methods for asymmetric olefinations, in particular Horner-Wadsworth-Emmons (HWE) reactions, in the synthesis of certain natural products. Relying on asymmetric HWE reactions to access key building blocks, two natu-ral products, pyranicin and pyragonicin, were synthesized from common late intermediates. READ MORE
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3. General Protocols for the Preparation of Tröger's Base Analogues and Molecular Recognition by Designed Tröger's Base Receptors
Abstract : 2,8-Dihalo substituted analogues of Tröger’s base were prepared via the Tröger’s base condensation reaction. These compounds were used as synthetic intermediates for the preparation of otherwise inaccessible functionalized Tröger’s base analogues. READ MORE
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4. Synthesis and Applications of P-chirogenic Phosphine Boranes
Abstract : AbstractThis thesis reports the independent synthesis of both enantiomers of P-chirogenic phosphine ligands and the building blocks thereof, which are suitable for parallel synthesis efforts and for the generation of more diverse libraries of P-chirogenic compound. The use of P-chirogenic phosphine boranes in transition metal-catalyzed reactions, such as palladium-catalyzed allylic alkylation and amination, is also described. READ MORE
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5. Asymmetric Formation and Isomerization of Three-Membered Rings : Catalyst Development and Evaluation
Abstract : Enantiopure α-amino acid derivatives were prepared using a protocol which allows for highly controlled regio- and chemoselectivity in the hydrogenation/ hydrogenolysis of aza-Diels-Alder adducts. One of the resulting α-amino esters, (1S,3R,4R)-2-azabicyclo[2.2.1]heptane-3-carboxylic acid ethyl ester, was utilized further as a catalyst precursor. READ MORE