Sökning: "Cyclopropanation"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet Cyclopropanation.

  1. 1. Asymmetric Formation and Isomerization of Three-Membered Rings : Catalyst Development and Evaluation

    Författare :Sophie Bertilsson; Tobias Rein; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; allylic alcohol; α-amino acid derivative; aza-Diels-Alder reaction; aziridination; cyclopropanation; desymmetrization; epoxide rearrangement; kinetic resolution; lithium amide; rhodium-carboxylate; Kemi; Chemistry; Kemi; organisk kemi; Organic Chemistry;

    Sammanfattning : 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. LÄS MER

  3. 2. Towards Rational Design of Asymmetric Catalyst for Organometallic and Organocatalytic Reactions

    Författare :Antti Hartikka; Per Arvidsson; Albrecht Berkessel; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organocatalysis; Transition Metal Complex; Asymmetric; Aldol Reaction; Cyclopropanation; Diels-Alder; Reduction; Conjugate Addition; Organic chemistry; Organisk kemi;

    Sammanfattning : This thesis deals with synthetically modified chiral molecules and their application in asymmetric catalysis. The first part of the thesis describes the use of commercially available chiral diamine ligands in the iridium catalyzed transfer hydrogenation of aromatic ketones. LÄS MER

  4. 3. Synthesis and Applications of P-chirogenic Phosphine Boranes

    Författare :Magnus Johansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cytisine; gold I catalysis lipase; P-chirogenic; desymmetrization; phosphine; enantioselective cyclopropanation. enantioselective deprotonation; chirality; asymmetric synthesis; borane;

    Sammanfattning : 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. LÄS MER

  5. 4. Quantum Chemical Modelling of Enzymatic and Organometallic Reactions

    Författare :Ferran Planas; Fahmi Himo; Edina Rosta; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; DFT; enzyme; organometallic; mechanisms; organisk kemi; Organic Chemistry;

    Sammanfattning : In this thesis, density functional theory (DFT) is employed in the study of two enzymes and two organometallic systems.First, the natural reaction mechanism, as well as the enantioselective formation of α-hydroxyketones catalysed by two thiamine diphosphate (ThDP)- dependent enzymes, namely benzoylformate decarboxylase (BFDC) and 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylic-acid (SEPHCHC)- synthase (MenD), are investigated. LÄS MER

  7. 5. Asymmetric Synthesis using Redox-Active Diazocompounds as Chiral Carbon Atom Precursors

    Författare :Matteo Costantini; Abraham Mendoza; Armido Studer; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; redox-active carbenes; mechanistic investigation; cyclopropanes; asymmetric catalysis; photochemistry; organisk kemi; Organic Chemistry;

    Sammanfattning : This thesis summarizes the development of general and efficient methods to synthesize enantiomerically enriched cyclopropane compounds. The works reported herein exploit the opportunity presented by redox-active esters to explore the orthogonality between asymmetric carbene-transfer and geminal radical generation. LÄS MER