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Showing 1 to 20 of 33 for “"Hydrogen atom transfer"”.

  1. Kinetic and Spectroscopic Investigation of Structural Influences on Hydrogen-atom Transfer Reactivity of N5-Ligated Oxomanganese(IV) Complexes

    Massie, Allyssa AUniversity of Kansas2018

    … manganese-oxo intermediates perform important hydrogenatom transfer (HAT) reactions in both biological and synthetic systems. There has been extensive characterization of HAT reactivity of enzymatic and synthetic oxoiron(IV) species, and these complexes have been shown to cleave a wide range of …

    ku Repository record

  2. Permanganate oxidations of aromatic hydrocarbons in aqueous and organic solution

    Gardner, Kimberly A. (Kimberly Annette), 1967-1996

    … reaction that appears to form a charge transfer complex. All of the data are consistent with rate limiting hydrogen atom transfer from the substrate to an oxo group of permanganate. The enthalpies of activation for the various substrates are shown to be directly proportional to the …

    washington Repository record

  3. Quantum Mechanical/molecular Mechanical Studies of F(1)-Atpase and a Plant Photoreceptor

    Dittrich, MarkusUniversity of Illinois at Urbana-Champaign2015

    … proceed via a neutral radical state generated by hydrogen atom transfer from the reactive cysteine residue, C57, to the chromophore flavin mononucleotide. Interestingly, we find that adduct formation does not cause any larger scale conformational changes in Phot-LOV1 which suggests that dynamical …

    uiuc Repository record

  4. The Application of Catalysis based on Hydrogen Bonding and Ion-pairing Interactions to Asymmetric Minisci-type Alkylations of Azines and Iridium-Catalysed C-H Borylation.

    Gibson, DavidUniversity of Cambridge2021

    … chemistry. The most widely used interactions, hydrogen bonding and ion-pairing, are employed in this thesis for the accomplishment of two important transformations in an enantioselective manner. The directionality of hydrogen bonding makes it a valuable tool for engendering asymmetry in organic …

    cambridge Repository record

  5. Mechanistic and synthetic studies of the intramolecular [4+2] cycloaddition of conjugated enynes

    Hayes, Martin Elliott, 1974-Massachusetts Institute of Technology2004

    … and dihydroaromatic compounds through proton transfer or hydrogen atom transfer mechanisms. Studies of the intramolecular cycloaddition of conjugated arylacetylenes (arenynes) indicated that these compounds may react by a stepwise annulation mechanism involving biradical intermediates. An …

    mit Repository record

  6. Advancements in the synthesis of distorted tricoordinate phosphorus compounds and their use as platforms in reductive chemistries

    Mattos, Jared Thomas.Massachusetts Institute of Technology2019

    … activation of water to generate equivalents of hydrogen. Chapter four explores the activation of both hydrazine and hydrazones by a distorted phosphoramidite and initial results in the use of these phosphoranes as platforms for hydrogen atom transfer chemistry. Chapter five presents a unique …

    mit Repository record

  7. Progress towards the enantioselective total synthesis of trichodermamide B

    Levinn, Carolyn MUniversity of Illinois at Urbana-Champaign2017

    … include the mild installation of an oxime with hydrogen atom transfer, and microbial arene oxidation to generate decagram amounts of enantiopure, value-added starting materials. This strategy has enabled rapid access to large quantities of advanced intermediates, and once complete, should afford …

    uiuc Repository record

  8. Synthesis of peptide-ligand conjugates and their applications

    Jabre, Nitinkumar Dilipkumar2011

    … ferryl-peptide conjugate via an intramolecular hydrogen atom transfer mechanism.</p>

    wayne-thes Repository record

  9. Partnering Photochemical Protocols With Anion Relay Chemistry: Application In The Total Synthesis Of Natural Products

    Deng, Yifan2021

    … or dioxolanyl radicals via [1,5]- or [1,6]-hydrogen atom transfer (HAT). This radical relay tactic enables remote C(sp3)-H functionalization to access synthetically challenging 1,4,7-polyol and spiroketal segments, and in turn, has been exploited as the key synthetic transformation in the …

    penn Repository record

  10. METAL-FREE SELECTIVE SP3 C-H IMINATION AND COVALENT POSTSYNTHETIC MODIFICATION OF POLYSTYRENE BY DIRECT C-H AMINATION

    Hu, MengnanUniversity of Houston2023

    … C-H imination. Our approach involves a unique hydrogen-atom transfer/radical addition mechanism, which differs from the more established Hoffman-Löffler-Freytag amination. From there, we have successfully transferred this method from small molecules to macromolecules, as the amino functional …

    houston Repository record

  11. Utilising Non-Covalent Interactions in Developing Enantioselective Radical Transformations

    Bacos, Paul DavidUniversity of Cambridge2023

    … phosphoric acids, bound to the substrate via hydrogen bonding, could induce asymmetry. The subsequent approach relied on using an anionic ligand, ion-paired to a chiral cation derived from cinchona alkaloids, to create a chiral environment around the metal centre. The challenges encountered …

    cambridge Repository record

  12. A novel photocatalytic strategy for complex aliphatic amine synthesis and the total synthesis of alkaloids (−) FR901483 and (+)-TAN1251C

    Reich, DominikUniversity of Cambridge2020

    … is described, revealing an unusual 1,5-hydrogen atom transfer step and an unprecedented redox-relay of iminium ions. In further studies, the reaction scope was expanded to include non-benzylic amines and enamines, enabling the generation of synthetically valuable $\alpha$-tertiary …

    cambridge Repository record

  13. Hydrogen Abstraction by the Nighttime Atmospheric Detergent NO3·: Fundamental Principles

    Paradzinsky, MarkVirginia Tech2021

    … of much work. Despite this, studies on NO3· hydrogen atom transfer reactions have been somewhat neglected in favor of its more reactive oxidative pathways. The first section of the dissertation will highlight the role of substrate structure, solvent effects, and the presence of a polar …

    vt Repository record

  14. Synthesis Of N-Acetyl And C-Tert-Butyl Natural Amino Acid Substrates That Mimic Residues Of Polypeptides And Their Reactivity With [feiv(o)(n4py)]2+: Kinetic And Mechanistic Investigations

    Campanali, Ashley Ann2011

    … reactive substrates were investigated. Electron-transfer proton-transfer and hydrogen atom transfer mechanisms are suggested for the substrates derived from Cys and Tyr, respectively, for their reaction with [FeIV(O)(N4Py)]2+. An electrophilic aromatic substitution mechanism is suggested for the …

    wayne-thes Repository record

  15. Generation of Alkyl Radicals Via C-H Functionalization and Halogen Atom Transfer Processes

    Niu, Ben2022

    … The first is C-H bond functionalization via hydrogen-atom-transfer (HAT). HAT processes have been used as an effective approach for selectively activating C-H bonds via radical pathways. The other strategy to explore the generation of alkyl radicals is C-X bond functionalization via …

    iupui Repository record

  16. Primary photoprocesses of light-activated antiviral and antitumor agents, hypericin and hypocrellin

    Smirnov, Alexandre1999

    … analogs that are unable to execute proton transfer, it was demonstrated that intramolecular excited-state hydrogen atom transfer is a dominant primary nonradiative process;For hypocrellin A in viscous solvents such as octanol and ethylene glycol, an absorption transient of ∼10-ps duration, …

    iastate Repository record

  17. Development of New Organic Photoredox Catalysis Driven by Visible Light

    Zhang, YuetengThe University of Arizona.2020

    … 9,10-phenanthrenequinone (PQ) promotes hydrogen atom transfer (HAT) to selectively generate acyl radicals from corresponding aldehydes without inducing crossover reactivity of thioesters. In situ formed acyl radicals then react with thiosulfonate S-esters to efficiently produce …

    arizona-thes Repository record

  18. New explorations in visible-light mediated energy and single electron transfer for nitrogen heterocycle synthesis

    Oddy, Meghan JessicaDepartment of Chemistry2024

    … might otherwise need high temperatures, poor atom economy or harsh reactants to proceed. This thesis explores the use of visible-light mediated photocatalysis for the synthesis of biologically important nitrogen containing heterocycles, investigating both single electron transfer and energy …

    cape-town Repository record

  19. Mono- and Dinuclear Nonheme Iron Model Complexes: O-O Bond Activation, Structural Characterization and Reactivity Study

    Rohde, Gregory2015

    … Chem. 2010, 756-759) In Chapter 5, the hydrogen atom transfer (HAT) rates of a series of S = 2 mononuclear nonheme iron complexes, [FeIV(O)TMG2dien(X)]2+,+ (X = CH3CN, Cl-, Br-, N3-, CH3CO2- and CF3CO2-; TMG2dien = 1,1-bis{2-[N2-(1,1,3,3- tetramethylguanidino)]ethyl}amine), were …

    umn Repository record

  20. Photolytic Studies of Aryl and Heteroaryl Nitrenium Ions: Laser Flash Photolysis Studies

    Thomas, Selina Ivan2006

    … With arenes, these ions react via electron transfer mechanism and nucleophilic addition process. The rate constants for the electron transfer mechanisms are between 10<sup>5</sup> - 10<sup>9</sup> M<sup>-1</sup> s<sup>-1</sup> and depend on the Eox of the arenes. Arenes with Eox above 1.78 V …

    maryland Repository record

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