Search for dissertations about: "DBU"

Showing result 6 - 10 of 10 swedish dissertations containing the word DBU.

  2. 6. Towards synthesis of biologically important phosphate analogues : exploring H-phosphonate and C-phosphonate chemistry

    Author : Annika Kers; Robert Letsinger; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Organic Chemistry; organisk kemi;

    Abstract : This thesis is based on studies directed towards the development of methods for the preparation of phosphorus containing natural products, with the focus on C-phosphonate nucleic acid analogues.Mechanistic studies concerning formation of the phosphorus-carbon bond resulted in development of two efficient protocols for the synthesis of C-phosphonates from the corresponding H-phosphonate derivatives. READ MORE

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

    Author : Sophie Bertilsson; Tobias Rein; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  5. 8. Active friction control by using CO2 and moisture

    Author : Jing Hua; Shi Yijun; Shah Faiz; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; friction control; Machine Elements; Maskinelement;

    Abstract : Nowadays the demand for intelligent control of tribological interactions is strongly increasing in various applications. We often strive to minimize friction but there are also many situations where high friction is desirable. In some cases, something in between, i.e. READ MORE

  6. 9. Investigations of New Biomimetic Transamination Systems and Inclusion Complexation with Cyclodextrins

    Author : Anders Hjelmencrantz; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; stereochemis; bicyclooctanes.Transamination; complexation; cyclodextrins; proton transfer; hydride transfer; stereochemistry; Transamination; Organic chemistry; Organisk kemi;

    Abstract : Two new transamination systems are described. The first example is a dibenzo[a,d]- cycloheptene containing system, designed to accomplish a [1,3]-hydride transfer. Several catalysts have been examined for this purpose. tris-Pentafluorophenyl borane was found to be the most efficient catalyst. READ MORE

  7. 10. Stimuli-Responsive Materials Derived from Cellulose Nanofibrils : Synthesis, characterization, and performance evaluation

    Author : Frédéric Héraly; Jiayin Yuan; Lennart Bergström; Leonid Ionov; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; bio-based materials; cellulose nanofibrils; CO2 sorption; soft actuators; stimuli-responsive materials; materialkemi; Materials Chemistry;

    Abstract : This thesis presents a comprehensive study on stimuli-responsive materials derived from cellulose nanofibrils (CNFs), focusing on their synthesis, characterization, and performance evaluation in various applications. Renowned for their biodegradability, renewability, and robust mechanical properties, CNFs are explored in three primary contexts: moisture-responsive actuators, voltage-responsive actuators, and CO2-responsive sensors. READ MORE