Search for dissertations about: "semi organic"

Showing result 1 - 5 of 105 swedish dissertations containing the words semi organic.

  2. 1. Self-adaptable catalysts : Importance of flexibility and applications in asymmetric catalysis

    Author : Ester Fjellander; Christina Moberg; Jay Siegel; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; adaptable; flexible; semi-flexible; symmetry; conformational study; mechanistic study; rotation barrier; VT NMR; asymmetric catalysis; ligand design; allylic alkylation; hydrogenation; azepines; dioxaphosphepines; phosphepines; amines; phosphines; phosphoramidites; phosphinites; palladium; rhodium; Organic chemistry; Organisk kemi;

    Abstract : The topic of this thesis is the design and synthesis of biaryl-based self adaptableligands for asymmetric metal catalysis. The results discussed in papers I-III are covered, together with some unpublished results concerning substrate-adaptable catalysts. A general survey of self-adaptable catalysts is presented first. READ MORE

  4. 2. BIOACTIVE SECONDARY METABOLITES -Isolation Characterization and Synthesis

    Author : Carola Valdivia; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Organisk kemi; Organic chemistry; Baccharis genistelloides; Piper heterophyllum; Myrtus Communis; Coprinus heptemerus; Thapsia garganica; Piper longestylosum; Piper obliquum; Natural Products;

    Abstract : Nature produces biologically active and chemically intriguing secondary metabolites. To isolate and characterize compounds of novel activity and structure, bioassay-guided fractionations were applied to several plants as well as to a basidiomycete. READ MORE

  5. 3. Flexibility – a tool for chirality control in asymmetric catalysis

    Author : Raivis Zalubovskis; Christina Moberg; Alexandre Alexakis; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; flexibility; symmetry; dissymmetry; asymmetric catalysis; chiral ligands; pseudo-C2; pseudo-CS; conformational study; rotation barrier; pyrrolidines; phospholanes; azepines; phosphepines; supramolecular; hydrogenation; allylic alkylation; silaboration; palladium; rhodium; nickel; platinum; iridium.; Organic chemistry; Organisk kemi;

    Abstract : This thesis deals with the design and synthesis of ligands for asymmetric catalysis: palladium catalyzed allylic alkylations, and rho-dium and iridium catalyzed hydrogenations of olefins. Chirally flexible phosphepine ligands based on biphenyl were synthesized and their properties were studied. READ MORE

  6. 4. NMR spectroscopy in structural and conformational analysis of bacterial polysaccharides

    Author : Carolina Fontana; Göran Widmalm; Sven Müller-Loennies; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Nuclear Magnetic Resonance; carbohydrates; O-antigen polysaccharide; organisk kemi; Organic Chemistry;

    Abstract : Carbohydrates constitute one of the three major classes of biomolecules found in all living cells and, unlike nucleic acids and proteins, their polymeric structures are not based on a template. The structural diversity of these molecules confers them an enormous capacity to encode information in biological systems, acting as efficient mediators in the interaction of the cell with the environment. READ MORE

  7. 5. Red Glass Coloration : a Colorimetric and Structural Study

    Author : Torun Bring; Lars Kloo; Alicia Duran; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; Organisk kemi;

    Abstract : Syftet med detta arbete har varit att försöka hitta alternativ till det kadmiumbase¬rade röda pigment som används idag. Detta har gjorts genom att delvis under¬söka kombinationer av grundämnen som i litteraturen finns omnämnda som röda glaspigment, delvis genom att försöka förbättra och underlätta produktionen av redan kända, men problematiska pigment. READ MORE