Sökning: "steric restriction."

Hittade 3 avhandlingar innehållade orden steric restriction..

  1. 1. Atom and Group Transfer Reactions Involving High-valent Iron Complexes

    Författare :Yong Li; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Iron enzymes; high-valent iron intermediates; bio-inspired iron complexes; FeIV=O; FeIV=NR; catalytic reactions; electronic effects; steric restriction.;

    Sammanfattning : Iron enzymes play critical roles in biological oxidation reactions by utilizing highly reactive high-valent iron intermediates, such as FeIV=O, FeV(O)(OH), and FeIV=NR species, for catalytic reactions. These intermediates exhibit remarkable catalytic behavior with high reactivities and high regio- and stereospecificity in various biochemical reactions. LÄS MER

  3. 2. Fast Chemistry by Microwave Heating : First Descriptions of Highly Enantioselective Microwave Protocols for Metal Catalysis; First Descriptions of in-situ Gas Generation for Fast Combinatorial Microwave Chemistry

    Författare :Nils-Fredrik K. Kaiser; C. O.; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmaceutical chemistry; Farmaceutisk kemi; Pharmaceutical chemistry; Farmaceutisk kemi; Organic Pharmaceutical Chemistry; organisk farmaceutisk kemi;

    Sammanfattning : Microwave heating was applied to different palladium-catalyzed allylic substitution reactions. The use of various nucleophiles demonstrated C-, N-, O- and S- nucleophilicity. High yields and stereopurities of the corresponding alkyls, amides, ethers and sulfones were afforded after only 30 – 120 s of heating. LÄS MER

  4. 3. Development of oligonucleotide based artificial ribonucleases 2'-O-MeOBAN´s and PNAzymes

    Författare :Merita Murtola; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : The present thesis is based on three parts. The first and second part describe the development of two different classes of metal-ion dependent artificial ribonucleases, 2'-O-methyl-ribonucleic acid based artificial ribonucleases (2'-O-MeOBANs) and peptide nucleic acid based artificial ribonucleases (PNAzymes). LÄS MER