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Showing 1 to 20 of 43 for “"Alkyl groups"”.
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Transfer of alkyl groups in novel amidine dications and other superelectrophiles
… under mild conditions led to extremely facile alkyl transfer from an sp3-hybridised nitrogen centre to very weakly nucleophilic triflate anions. For the reaction pathway of substrates III and VII, in silico studies propose an equilibrium between the more stable tetrahedral triflate intermediate …
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Synthesis of Single Isomer Trisubstituted Olefins from beta-chloro-alpha-iodo-alpha, beta-Unsaturated Esters and Alkynyl Esters
… esters cross-couple with 9-alkyl-9-BBN to produce single isomer trisubstituted olefins using palladium-catalyzed Suzuki-Miyaura cross-coupling reaction. This methodology can be further expanded to introduce various alkyl groups at the beta-position. The mechanism is somewhat …
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PHOTOCHEMICAL HYDROXYLATION OF 1-METHYLANTHRAQUINONES: SYNTHESIS OF 9`-HYDROXYALOESAPONARIN II
… excited 9,10-anthraquinones can abstract H from alkyl groups ortho to the carbonyl. The hydrogen transfer results in a 1,x biradical which then undergoes a variety of reactions. One of these, oxidation of an alkyl substituent ortho to one of the carbonyls, was believed to go through formation of …
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Mechanistic Studies of the Chemical Vapor Deposition of Ceramic and Metal Films From Organometallic Precursors
… (D)} = 5.2 \pm 0.4)$ upon deuterating the alkyl groups at the $\alpha$ positions provides clear evidence that the initial step in the thermolysis is an $\alpha$-hydrogen elimination reaction to form neopentane. The activation parameters for this $\alpha$-hydrogen elimination process are …
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Part I. Aromatic Fluorinations for Fluorine-18 Labeling of Estrogens. Part Ii. Bromodesilylation-Potential Method for Regiospecific Radiobromination of Aromatic Systems. Part Iii. Synthesis of Isohexestrol and Isohexestrol Derivatives
… fails with ortho methoxy or methanesulfonyloxy groups. The aryl azide method gives good yields of p-fluoroanilines, which can be deaminated readily, but oxygen or large alkyl groups ortho to the azide interfere with the fluorination. The synthesis of meta-fluorohexestrol, a non-steroidal …
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Pyrolysis-gas chromatography by direct injection of solutions
… for analyzing aqueous solutions containing the alkylbenzene sulfonates. This method provides not only a measure of the total detergent present but also differentiates between the various alkyl groups found in the commercial products. The alkyl groups form the 1-alkenes which can be easily …
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Polymers for electronics and chemical sensing applications
… molecular frameworks, strong hydrogen bond donor groups or perfluoro-alkyl groups can result in considerable gains in the performance of some established polymeric materials. This dissertation details the synthesis and properties of polymers that demonstrate such types of functionality for …
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New immobilized antimicrobial polyethylenimines : synthesis and properties
Surfaces modified with immobilized N-alkyl-polyethylenimines (N-alkyl-PEls) containing various alkyl groups were synthesized and tested against various pathogenic human influenza viruses to establish structure-to-virucidal activity relationships. Various physical-chemical properties of each surface …
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Computer Methods for Investigating Hydrogen-Bonded Equilibria in Alcohols
… hydrogen bonding is reviewed in relation to O-H groups in alcohols and the use of physical methods, particularly infrared spectroscopy, and computing methods to gain better understanding of the structures arising from the formation of hydrogen bonds.<br/><br/>The infrared spectra of methanol as a …
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Combinatorial approach to multi-substituted 1,4-Benzodiazepines as novel non-peptide CCK-antagonists
… moiety was chemically modified by selective alkylation and acylation reactions. These studies provided a series of Asperlicin naturally analogues. The fully optimised Asperlicin related compound possessed a similar CCKA activity as the natural occuring compound. 3-Alkylated …
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Synthesis and application of sterically flexible and water-soluble phosphine ligands in palladium catalysis
… through collaboration with the Dixon and Rogers groups, seeks also to better understand how phosphine ligand structure influences catalysis in order to design more effective systems. My work began with the study of the influence of flexible, electron-rich phosphine substituents such as the …
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INHIBITION OF THE SERINE PROTEASE CHYMOTRYPSIN BY A SILANEDIOL PEPTIDE MIMIC: ASYMMETRIC SYNTHESIS AND INHIBITION STUDIES
Dialkylsilanediols are non-hydrolyzable analogs of the tetrahedral intermediate of amide hydrolysis and have shown outstanding inhibition of metallo and aspartic proteases. This research describes the synthesis and inhibition of the serine protease α- chymotrypsin by silanediol structures and the …
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Organolead Compounds in Natural Systems
Most organolead compounds with alkyl groups attached to a central lead atom are many times more toxic than inorganic lead compounds. The widespread use of tetraethyllead and tetramethyllead as antiknock agents in gasoline, and consequently their emission or discharge into the environment, is …
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Reactions of Organolead Compounds Under Natural Conditions
Certain compounds containing lead atoms bonded to alkyl groups are of much greater toxicity than their non-alkylated analogues. The tetra-alkyl lead compounds are used as anti-knock additives in petrol and are discharged into the atmosphere by exhaust emission, spillage, and evaporation. Because of …
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Stereospecific Csp3 cross-coupling for modular polyketide synthesis
… molecules due to challenges in the coupling of alkyl groups using Suzuki-Miyaura cross-coupling reactions. Here, I show that stereospecific palladium-catalyzed cross-coupling reactions of secondary alkyl organoboron nucleophiles can be leveraged to access the alpha-methyl-beta-hydroxyl motif …
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Investigation of electrochemical interfaces at the molecular level
… (< 0.3 V), interactions between Ag and alkyl groups in neutral glycerol molecules dominate on the electrode surface. The C–H vibrational modes exhibit a considerable redshift, indicating a strong interaction between the alkyl groups and Ag surface, possibly involving charge transfer. As …
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Pyrogallo4arenes: a synthetic investigation
… compared to the well-documented resorcinarenes. Alkylation of the pyrogallolarene macrocyle with ethyl bromoacetate was successfully achieved and analysis of both isolated products (rccc and rctt) revealed that the original conformations are maintained and are temperature stable. The same acidic …
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Understanding of Molecular Interactions and Reversibility in Silylamines
… mixture. These experiments revealed that the alkyl groups may participate in interactions upon addition of lithium hexafluorophosphate salt, which results in inhibited diffusion. This signals a possible route for tuning the TPSA structure to improving the conductivity and salt solubility for …
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