Sökning: "coupling chemistry"

Visar resultat 16 - 20 av 340 avhandlingar innehållade orden coupling chemistry.

  1. 16. Studies of oligosaccharides and carbon-13 enriched bacterial polysaccharides using NMR spectroscopy and computer simulations

    Författare :Alexandra Kjellberg; Steven Homans; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Organic Chemistry; organisk kemi;

    Sammanfattning : The conformation and dynamics of the trisaccharide methyl β-D-Glcp-(1--> 2)[β-D-Glcp-(1 --> 3)] α-D-Manp and its constituent disaccharides methyl β-D-Glcp-(1 --> 2) α-D-Manp and methyl β-D-Glcp-(1 --> 3) α-D-Manp have been studied using computer simulations and NMR spectroscopy. The computer simulations applied were Metropolis Monte Carlo simulations employing the HSEA force field and Langevin dynamics simulations using the PARM22 and CHEAT95 force fileds. LÄS MER

  2. 17. Methods for Determination of Benzo(a)pyrene and High Molecular Weight (>300 Da) Polycyclic Aromatic Hydrocarbons in Particulate Matter from Ambient Air and Vehicle Exhausts

    Författare :Christoffer Bergvall; Roger Westerholm; Stephen Wise; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PAH; dibenzopyrene; benzo a pyrene; standard reference material; air particulate matter; diesel particulate matter; toxic equivalence factor; ultrasonic assisted extraction; accelerated solvent extraction; automation; online coupling; GC MC; LC GC MS; Analytical chemistry; Analytisk kemi; Analytical Chemistry; analytisk kemi;

    Sammanfattning : Air pollution with particulate matter (PM) raises considerable concern because of its adverse effects on human health. For this reason, and because the mechanisms of PM toxicity are not fully known, there is an urgent need to determine the chemical constituents of atmospheric PM, especially PM emanating from traffic - a major source of urban PM. LÄS MER

  3. 18. Enantioenriched Cyanohydrins and Acetoxyphosphonates – Synthesis and Applications

    Författare :Robin Hertzberg; Christina Moberg; Frank Glorius; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; asymmetric synthesis; cyanohydrins; acetoxyphosphonates; biocatalyst; titanium catalyst; minor enantiomer recycling; cross-coupling; amino alcohols; Kemi; Chemistry;

    Sammanfattning : In this thesis, the synthesis of enantioenriched compounds using novel methodologies that employ metal- and biocatalysis is described.In the first part, the synthesis of enantioenriched cyanohydrins, which are highly versatile synthetic intermediates, is described. LÄS MER

  4. 19. Asymmetric Synthesis and Mechanistic Studies on Copper(I)-Catalyzed Substitution of Allylic Substrates

    Författare :Jakob Norinder; Jan-Erling Bäckvall; Norbert Krause; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; copper; allylic substitution; ferrocene; DYKAT; cross-coupling; homo-coupling; DFT; Organic chemistry; Organisk kemi;

    Sammanfattning : This thesis deals with the copper-catalyzed substitution of allylic substrates.In the first part of this thesis, the synthesis of a series of metallocenethiolates is described. The thiolates were examined as ligands in the enantioselective copper(I)-catalyzed γ-substitution of allylic acetates. LÄS MER

  5. 20. New methods for determination of airborne pollutants : Focus on tetrabromobisphenol A, organophosphate triesters and polycyclic aromatic hydrocarbons

    Författare :Johanna Tollbäck; Ulrika Nilsson; Peter Haglund; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Air sampling; sampling methods; indoor air; SPE; SPME; extraction; dynamic extraction; online coupling; SWE; subcritical water extraction; GC MS; LC MS; organophosphate triesters; PAH; tetrabromobisphenol A; Analytical chemistry; Analytisk kemi; Analytical Chemistry; analytisk kemi;

    Sammanfattning : The work presented in this thesis concerns the development and evaluation of new methods of sampling and analysis of organic pollutants in the indoor and outdoor environment. In Paper I, the development of a new method was reported for the determination of the brominated flame retardant tetrabromobisphenol A (TBBPA) in air using sampling with glass fiber filter and polyurethane foam (PUF), ultrasonic solvent extraction and liquid chromatography coupled to electrospray ionisation mass spectrometry (LC-ESI/MS). LÄS MER