Sökning: "Tobias Rein"

Hittade 4 avhandlingar innehållade orden Tobias Rein.

  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. Stereoselective Nucleophilic Additions to Aldehydes and Synthesis of α-Amino-β- Hydroxy-Esters

    Författare :Jakob Danielsson; Peter Somfai; Hans Adolfsson; Tobias Rein; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asymmetric induction; stereochemical models; Mukaiyama; polar Felkin-Anh; Cornforth-Evans; 1; 3-dipole; aziridine; cycloaddition; amino alcohol; carbonylation; Heck reaction; quaternary stereocenter;

    Sammanfattning : This thesis deals with the development of new reaction methodology as well as stereochemical investigations. The first part concerns the investigation of 1,2- and merged 1,2- and 1,3- asymmetric induction in Mukaiyama aldol additions to α-heteroatom and α,β- heteroatom substituted aldehydes respectively. LÄS MER

  4. 3. Palladium(II)-Catalyzed Reactions of Allenes with Lithium Bromide and Cyclization of α-Amino Allenes to Pyrrolines

    Författare :Attila Horváth; Jan-Erling Bäckvall; Tobias Rein; Stockholms universitet; []
    Nyckelord :Palladium; allene; pyrroline; palladium II -catalysis;

    Sammanfattning : This thesis is based on three novel palladium(II)-catalyzed reactions of allenes with lithium bromide and a bromonium ion induced cyclization of allenyl amides to pyrrolines. In Paper I a 1,2-functionalization of allenes is presented where bromide adds as a first nucleophile followed by intramolecular attack by an oxygen or nitrogen nucleophile. LÄS MER

  5. 4. 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