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Showing 1 to 19 of 19 for “"SNAr"”.
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Kinetic Studies of 6-Halopurine Nucleoside in SNAr Reactions; 6-(Azolyl, Alkylthio and Fluoro)-purine Nucleosides as Substrates for Suzuki Reactions
… development of a mild and efficient method for SNAr iodination of 6-chloropurine 2'-deoxynucleosides and nucleosides. Our studies demonstrate that 6-iodopurine nucleosides are excellent substrates for certain transition metal-catalyzed cross-coupling reactions. In chapter 2, we describe …
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Polyfluorinated Aromatic Systems for Liquid Crystal Display Applications
… respectively. SNAr reactions of sodium phenoxide with less electrophilic 1,2,3,4–tetra– and 1,2,3,5–tetra–fluorobenzene under microwave irradiation (150 °C, 30 mins) furnish good yields of 1,2,4–trifluoro–3–phenoxybenzene and 1,2,5–trifluoro–3–phenoxybenzene, …
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Peptide-mediated delivery of antisense oligonucleotides and chemotherapeutics across biological barriers
… peptide cyclization with perfluoroaryl-cysteine SNAr chemistry to improve the stability and delivery of peptide-ASO conjugates. We extend our SNAr chemistry to the synthesis of arginine-rich bicyclic peptides, which are more stable to proteolysis than single cycles. Both perfluoroaryl cyclic and …
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Mild and Convenient Methods to Prepare N-Alkyl Tacrines
… by the standard SNAr methods was unsuccessful and thus alternatives needed to be developed to synthesize N-alkylated and bivalent 12-chloro-2-methyl-6,7,8,9,10,11-hexahydrocycloocta[b]quinoline. Upon exploring the alternatives, N-arylation by Pd-catalysis seemed to …
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Regioselective, Nucleophilic Activation of C-F Bonds in o-Fluoroanilines
… Based on results, we propose a metal-mediated, SNAr-based mechanism. We report the scope and limitations of this reaction and discuss trends in reactivity according to a putative mechanistic scheme.
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Áhrif menningar í alþjóðaviðskiptum : hverjir eru helstu áhrifaþættir ólíkra menninga í samningaviðræðum?
… verið að leiðrétta. Menningarlæsi er þannig snar þáttur í hæfni fyrirtækja í alþjóðaviðskiptum.
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Towards the synthesis of RP66453
… macrocycle (ether ring) was achieved via an SNAr ring closure. Coupling of this fragment to an advanced tetrapeptide intermediate was achieved. Further macrocyclisation is needed to advance this material to the natural product.
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Development of Pd Catalyzed Amidations & Applications to the Synthesis of Heterocycles
… C2 halogenation followed by substitution (SNAr) with functionalized primary and secondary amines. This regioselective sequence is operationally simple and provides an easy access to derivatives of protected imidazo[4,5-b]pyridines.</p> <p>Chapter 4</p> <p>Pentosidine, a biologically …
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The design and synthesis of organic chromophores for Faraday rotation and photoluminescence
… chalcogenides. We utilized dynamic covalent SNAr behavior to demonstrate selective depolymerization. In addition, we studied the mechanism of the bright photoemission, ascribing it to delayed fluorescence enabled by the presence of sulfur atoms. In Chapter 5, we discuss the synthesis and …
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Rapid Synthesis, Characterization, and Catalytic Function of Rhodium(III) and Iridium(III) Chloro-bridged Dimers
… alkyl, 12 examples; R = aryl, 3 examples) or by SNAr reactions of potassium tetramethylcyclopentadienide with perfluoroarenes (R = perfluoroaryl, 3 examples). Reaction of the Me4CpHR ligands with [M(COD)](μ2-Cl)2 (M = Rh, Ir; COD = 1,5-cyclooctadiene) produced the dimeric complexes …
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Azobenzenes for the development of therapeutics
… systems primed for peptide stapling via cysteine-SNAr. Specifically, a tetra-ortho-chloro azobenzene motif that can undergo bi-directional visible- light mediated isomerisation. As a proof-of-concept, we employed this newly developed peptide stapling methodology to target the disruption of …
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Cysteine arylation
… through a nucleophilic aromatic substitution (SNAr) mechanism, fluorinated aromatic reagents are used for the regioselective arylation of a single cysteine in the presence of many. An enzyme-tag pair (glutathione S-transferase (GST) and glutathione (GSH)) and a self-labeling short peptide …
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Automated feedback in flow for accelerated reaction screening, optimization, and kinetic parameter estimation
… of reaction kinetics in a series-parallel SNAr reaction network. Unfortunately, the most challenging aspect of reaction development tends not to necessarily be the continuous variables, but rather the enumerate combinations of discrete variables-e.g. catalysts, ligands, and solvents-that, …
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Eyðing alaskalúpínu (Lupinus nootkatensis) með plöntueitri: áhrif á annan gróður
… rekja til þess að samkeppni við lúpínu snar minnkar og opnur myndast í sverðinum. Áhugavert væri að fylgjast með framvindunni til lengri tíma.
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Perfluoroarylated Cyclopentadienones: Synthesis, Characterization and Polymerization
… attached by nucleophilic aromatic substitution (SNAr) reactions. The remaining ring methylenes are subjected to a selenium dioxide-catalyzed oxidation to obtain the desired bis(cyclopentadienone) monomer. The next part of this chapter describes the polymerization of the perfluoroarylated …
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Studies in Furobenzopyran Chemistry
… has been obtained via a tandem acylation-SnAr reaction of ethyl 2-fluorobenzoylacetate. Protolysis of dimethyl 1,4-dihydro-1,4-epoxy4-(4-methylphenyl)-9-oxo-9H-thioxanthene-2,3-dicarboxylate gives the expected 1-hydroxythioxanthone derivative. However, the analogous 1,4-epoxyxanthene …
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Replication of Sequence Information in Recognition-Encoded Synthetic Polymers
… three H-bonding recognition units, using SNAr chemistry was investigated. A 7-mer template was shown to ligate two bound 3-mers with an effective molarity of 5 mM. However, an off-template competing process where complementary 3-mers associate and react was found to be significantly more …
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Cyclopentadiene-Maleimide Platform for Thermally Reversible Polymers
… were prepared for this study using SNAr reactions of pentafluoropyridine and sodium cyclopentadienide. The least electron deficient cyclopentadiene in each series (Ar = C₆F₅) reacted the most quickly and with the highest ultimate equilibrium binding constant, confirming the …
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Flow Chemistry Guided by Computer-Aided Synthesis Planning
… two step sequence, amide coupling followed by an SNAr did not proceed under the CASP program reaction conditions. This work establishes a general approach for using CASP suggestions to guide development of telescoped flow chemistry. During this project, all work was performed by C.P.B. under …