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Showing 1 to 17 of 17 for “"Alkyl radical"”.
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The electrolysis of lithium alkyls and ethyl magnesium bromide in lithium borohydride-diethyl ether solutions
… through the anodic formation of a free alkyl radical by electrolyzing a solution of an alkyl alkali compound such as lithium ethyl, along with a simultaneous electrolysis of an alkali borohydride. The deposition of the free alkyl radical in the presence of the borohydride radical may …
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Development of copper-catalyzed enantioselective alkene difunctionalization reactions via radical intermediates
… are consistent with a metal-catalyzed redox radical addition mechanism, in which a C-0 bond is formed via the copper-mediated enantioselective trapping of a prochiral alkyl radical intermediate derived from the initial trifluoromethyl radical addition. Chapter 3 A general and versatile method …
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Mechanisms of antifatigue agents used in natural rubber
… quinones and phenols expected to have macroalkyl radical scavenging ability, BQ, αTOC, γTOC and GM showed relatively good performance for fatigue resistance (although their performance was slightly less effective than the commercial aromatic amine antioxidants, IPPD and 6PPD). The compounds …
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Photoredox Generated Radicals In Csp2-Csp3 Bond Construction
… to circumvent the problems associated with alkyl nucleophiles, application of these reagents in transition metal-catalyzed C-C bond-forming reactions has remained largely restricted. In recent years, many chemists have noted the lack of reliable, turnkey reactions that exist for the …
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The Antioxidant Function of Dithiophosphoryl Compounds in Rubbers
… quantitative study of the reaction between 0,0-dialkyldithiophosphoricacids and natural rubber latex, showed thata moderate yield of adduct was obtained using low concen~trations of the acids. High concentration of the acids causedcoagulation of the latex due to their acidity. Attempts tobind the …
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Mechanistic and preparative studies of Electrochemical Deoxygenation and Debromination
… step involves the reversible formation of a radical anion, followed by fragmentation to 3,5- bis(trifluoromethyl)benzoate and the corresponding alkyl radical. Subsequent electrochemical reduction of the radical would be expected to form a carbanion. Protonation, presumably by trace water …
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A Radical Approach to Photochemical Transformations Using Earth-Abundant Metals
… (OSET) process for the generation of open-shell radical species. While powerful, the efficiency of this approach is limited by the bimolecular diffusion rate of reactants and photocatalysts and a redox-potential matching requirement for productive oxidative/reductive quenching. By contrast, …
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Cation radical induced oxidative chemistry of hydrazones and oximes
Electron transfer reactions of cation radicals have drawn much interest (1). Shine and Sugiyama were the first to observe that alkyl radicals were formed by an initial electron transfer step in reactions of thianthrene cation radical with organomercurials (2). The possibility that thianthrene …
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Studies in Selective C-C Bond Formation via Borylation and Dehydrogenation
… stability afforded by boron to adjacent alkyl radicals. We demonstrate room temperature regioselective alkylation of pyridazines by (iodomethyl)boronic acid pinacol ester in the presence of trifluoroacetic acid in up to 70% yield (Chapter 1.3). We see that this reaction proceeds upon …
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New strategies for the synthesis and homologation of complex aliphatic amines
… assembly and late-stage modification of complex alkylamines represents a significant and enduring challenge in synthetic chemistry. This is due to the ubiquity of this chemical motif in biologically active small molecules and therapeutic agents. This thesis describes the design and implementation …
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Modular Methods for the Synthesis of α-Tertiary and α-Branched Alkylamines via Visible-Light-Mediated Radical Generation
… is a central goal of organic synthesis. Alkylamines are interesting synthetic targets because they occupy a privileged position in drug discovery yet are often highly challenging to synthesise. Complex alkylamines commonly feature branching at the α-position, which can further complicate …
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Free radical reactions of allylic and propargylic derivatives
<p>Addition of tert-butyl radical, generated from t-BuHgCl, to allyl or propargyl derivatives forms adduct radicals which can undergo [beta]-elimination with substituents such as halogen, PhS, PhSO[subscript]2 to form the alkyl-substituted propene or allene and an eliminated radical which …
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THE PHOTOCHEMISTRY OF POLYENYL RADICALS AND ITS APPLICATION TO UHMWPE FOR USE IN ARTIFICIAL CARTILAGE
… above the melting point (150 °C) to remove free radicals in irradiated UHMWPE was explored. It was found that, in contrast to the allyl free radical which is converted by 258 nm light to alkyl free radicals, polyenyl radicals are not converted to alkyl radicals by UV light. None-the-less, by …
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Computational Studies of Selected Ruthenium Catalysis Reactions.
… weak RuIII-C bonds would afford quick access to alkyl radical species. Calculations support the experimental proposal of a mechanism for catalytic hydrogen/deuterium exchange by a RuII-OH catalyst. Furthermore, calculational investigations reveal a probable pathway for the activation of C-H bonds …
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Thermochemistry and kinetics in pyrolysis and oxidation reaction of oxygenate chlorocarbons, neopentane, and ortho-xylene
… hydroperoxides and corresponding alkoxy, hydroxy alkyl radicals, peroxy and hydroperoxy alkyl radicals are determined by ab initlo and density functional calculations for modeling and optimization of complex chemical processes for combustion or incineration of chlorinated hydrocarbons. The entropy …
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Thermochemistry and kinetics: hydrogen atom addition reactions with alkenes, oxidation of cyclopentadienone, trifluoroethene and transport properties
… fluid dynamic modeling. Transport properties of radicals cannot be measured so computational chemistry is method of choice. The dissertation determine dipole moment, polarizability and molecular diameters of hydrocarbon and oxygenated hydrocarbons needed for calculation of multicomponent …
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Generation of Alkyl Radicals Via C-H Functionalization and Halogen Atom Transfer Processes
Alkyl radicals are powerful intermediates for the generation of carbon-carbon bonds, which play an indispensable role in the synthesis of natural products, pharmaceuticals, and pesticides. Traditionally, there are two main methods for the generation of alkyl radicals. The first is C-H bond …