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Visar resultat 1 - 5 av 8 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Bridging McMurry and Wittig in One-Pot : Olefins from Stereoselective, Reductive Couplings of Two Aldehydes via Phosphaalkenes

    Författare :Juri Mai; Sascha Ott; Christian Müller; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; carbonyl olefination; reductive aldehyde coupling; stereoselective; organophosphorus; phosphaalkene; phosphanylphosphonate; Wittig; Horner-Wittig; Horner-Wadsworth-Emmons; McMurry; Kemi; Chemistry;

    Sammanfattning : The formation of C=C bonds is of great importance for fundamental and industrial synthetic organic chemistry. There are many different methodologies for the construction of C=C bonds in the literature, but currently only the McMurry reaction allows the reductive coupling of two carbonyl compounds to form alkenes. LÄS MER

  3. 2. Olefins from carbonyls : Development of new phosphorus-based cross-coupling reactions

    Författare :Nicolas Daniele D'Imperio; Sascha Ott; Carlos Romero-Nieto; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; olefins; carbonyl olefination; phosphaalkenes; stereoselective synthesis; Wittig; Horner-Wadsworth-Emmons; McMurry;

    Sammanfattning : Olefins, compounds containing C=C double bonds, are omnipresent in nature and serve as useful starting materials for various chemical modifications. Olefins are of crucial importance in Medicinal Chemistry and are also present in essential objects like dyes, polymers and plastics. LÄS MER

  4. 3. Methods for Asymmetric Olefination Reactions; Development and Application to Natural Product Synthesis

    Författare :Daniel Strand; Tobias Rein; Viresh Rawal; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Antitumor agents; Asymmetric Horner-Wadsworth-Emmons; Desymmetrization; Metal-catalyzed olefination; Mucocin; Palladium-catalyzed allylic substitution; Parallel kinetic resolution; Pyranicin; Pyragonicin; Rhenium; Stereoconvergent synthesis; Stereodivergent synthesis; Stereoselective synthesis; Tetrahydropyran; Wittig reaction; Organic chemistry; Organisk kemi;

    Sammanfattning : 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. LÄS MER

  5. 4. Novel Approaches to Phosphorus-containing Heterocycles and Cumulenes

    Författare :Anna Arkhypchuk; Sascha Ott; John D. Protasiewicz; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phosphorus; phosphole; oxaphosphole; cumulene; phospha-Wittig-Horner reagent; molecular electronics; Chemistry; Kemi;

    Sammanfattning : Fast development in all areas of life and science over the last 50 years demands versatile, energy efficient and cheap materials with specific but easily tuneable properties which can be used for example in organic light emitting diodes (OLEDs), thin-film transistors, photovoltaic cells, etc. This thesis is devoted to the development of novel synthetic approaches to molecules with potential applications in the field of molecular electronics. LÄS MER

  7. 5. Palladium-promoted synthesis of compounds labelled with ¹¹C : Synthesis of ¹¹C-labelled prostacyclin and prostaglandin analogues

    Författare :Margareta Björkman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Chemistry; Kemi; organisk kemi; Organic Chemistry;

    Sammanfattning : Palladium-promoted reactions have been employed for the synthesis of compounds labelled with 11C (t½ = 20.3 min). The precursor [11C]methyl iodide was used in palladium-promoted cross-coupling reactions with organostannanes. LÄS MER