Sökning: "cycloaddition reactions"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden cycloaddition reactions.

1. 1. New Methods for the Synthesis of Vicinal Stereocenters : Palladium-Catalyzed Domino Reactions and Asymmetric Transfer Hydrogenation

   Författare :Brinton Seashore-Ludlow; Somfai Peter; Kevin Booker-Milburn; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; asymmetric synthesis; domino reactions; palladium-catalyzed reactions; oxindoles; amino alcohols;

   Sammanfattning : In this thesis the synthesis of vicinal stereocenters is investigated in two distinct contexts, namely the construction of 3,3-disubstituted oxindoles and the synthesis of b-hydroxy-a-amino acids. Both scaffolds are prevalent in a range of natural products and biologically relevant compounds and, therefore, methods for their synthesis are of great import. LÄS MER

3. 2. Transition-Metal Catalyzed Synthesis of Small- and Medium-Sized Rings Applications toward oxazole synthesis, cycloheptadienes, and natural products

   Författare :Henrik von Wachenfeldt; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; catalysis; transition metal; cyclization; cycloaddition; natural product;

   Sammanfattning : This thesis deals with the development of novel methodologies for the synthesis of hetero- and carbocycles enabled by transition metal catalysis. The second chapter of the thesis describes a gold-catalyzed three-component reaction to form a variety of substituted oxazoles from readily available N-benzylimines, terminal alkynes, and acyl chlorides. LÄS MER

4. 3. Quantum Chemical Studies of Protein-Bound Chromophores, UV-Light Induced DNA Damages, and Lignin Formation

   Författare :Bo Durbeej; Leif Eriksson; Tim Clark; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; quantum chemistry; calculations; density functional theory; excited states; photochemistry; chromophores; absorption spectra; bathochromic shift; isomerization; UV radiation; DNA damages; cycloaddition reactions; photoenzymic repair; electron transfer; lignin; polymerization; phenoxy radicals; dilignols; Kvantkemi; Quantum chemistry; Kvantkemi;

   Sammanfattning : Quantum chemical methods have been used to provide a better understanding of the photochemistry of astaxanthin and phytochromobilin; the photoenzymic repair of UV-light induced DNA damages; and the formation of lignin. The carotenoid astaxanthin (AXT) is responsible for the colouration of lobster shell. LÄS MER

5. 4. Quantum Chemical Modeling of Phosphoesterase Mimics and Chemistry in Confined Spaces

   Författare :Henrik Daver; Fahmi Himo; Gregori Ujaque; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density functional theory; catalysis; phosphoester hydrolysis; transesterification; supramolecular chemistry; inclusion complex; host-guest chemistry; cycloaddition; organisk kemi; Organic Chemistry;

   Sammanfattning : In this thesis, density functional theory is employed in the study of two kinds of systems that can be considered to be biomimetic in their own ways. First, three binuclear metal complexes, synthesized by the group of Prof. Ebbe Nordlander, have been investigated. LÄS MER

7. 5. Perfluroaryl azides : Reactivities, Unique Reactions and their Applications in the Synthesis of Theranostic Agents

   Författare :Sheng Xie; Mingdi Yan; Olof Ramström; Stefan Bräse; KTH; []
   Nyckelord :Click Chemistry; Dipolar Cycloaddition; Enamine; Triazoline; Amidine; Aggregation-induced emission; pure nanodrugs; aryl amide; thioacid azide reaction; nucleophilic aromatic substitution; azide-masked fluorophore; nitrene insertion; Kemi; Chemistry;

   Sammanfattning : The work centersaround perfluoroaryl azides (PFAAs), and theirability to undergo certain fast and robusttransformations. The chemistry was furtherappliedfor biomedical applications.The first section focuses on the azide-aldehyde-amine cycloaddition using PFAAs. LÄS MER