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Showing 1 to 13 of 13 for “"triazolium"”.
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Carbene catalyzed asymmetric nucleophilic acylations with novel triazolium salts
… we have developed different N-substituted triazolium salts, which successfully catalyzed the intermolecular Stetter reaction. The structure of 1-Methyl triazolidine was elucidated by X-ray structure analysis. Moreover, we have demonstrated that 1-methyl triazolidine lacked catalytic …
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Correlation of Aqueous Solubility and Anti-Cancer Activity of Novel Triazolium and Imidazolium Salts
<p>Novel triazolium, imidazolium, and benzimidazolium salts are known to possess anti-cancer properties and have potential as cancer therapeutics. This thesis describes the aqueous solubility and the differential activity of N,AT-bis-substituted-l,2,4-triazolium bromide salts and …
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Design and Synthesis of Chiral Triazolium and Thiazolium Salts Incorporating Hydrogen-Bonding Motifs as Organocatalysts
… designs are proposed. Synthetic routes to new triazolium and thiazolium salt catalysts with unreported chiral backbones are discussed. These involve 1,2-diamine derived salts, 1,4-diamine derived salts, amino acid-derived triazolium salts, and a bicyclic triazolium salt with a piperidine …
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Neue Heterazoliumsalze aus Prolin und Pyroglutaminsäure und Anwendungen in Carben-katalysierten asymmetrischen nucleophilen Acylierungen
… with bicyclic heterazolium salts: A chiral triazolium salt that had been developed in the group of Prof. Dr. D. Enders as precatalyst for an asymmetric benzoin condensation was employed in other carbene catalysed reactions (acyloin condensations, intermolecular Stetter reactions, reactions …
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An Exploratory Study of the Effects of BIS-Substituted Triazolium Bromide Salts on the Proliferation of WI-38 Lung Cells and H-1299 Lung Cancer Cells
… increased carbon content of the benzene on benzotriazolium salts (BT 2-2) exhibit a greater dose-dependent decrease in the proliferation of both normal and lung cancer cells. Studies with the T3 compounds, specifically T3 4-4, which has a smaller carbon core but similar large carbon content, like …
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Bicyclische Triazoliumsalze als Präkatalysatoren in der asymmetrischen Benzoin- und Acyloinkondensation und asymmetrische Synthese von Oxazolidin-2-onen
… the synthesis of a novel enantiopure bicyclic triazolium salt and its application as an efficient chiral catalyst in the form of the corresponding Wanzlick carbene in the asymmetric variant of the benzoin condensation is described. The chiral bicyclic triazolium salt is currently the most …
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Preparation of Novel Carbenes and their Catalytic Application to the Cross-Benzoin, Aza-Benzoin and Stetter Reactions
… carbenes (NHCs) derived from bicyclic triazolium salts possessing a fused 6 membered ring were found to induce chemoselectivity in the cross-benzoin between aromatic and aliphatic aldehydes. Use of these catalysts gave rise to predominantly one cross-benzoin product which could be …
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Entwicklung von Carben-katalysierten asymmetrischen intermolekularen Stetter-Reaktionen und direkt gekreuzter intermolekularer Benzoin-Reaktionen
A new chiral triazolium based carbene precatalyst was synthesized and successfully employed in the asymmetric intermolecular Stetter reaction. The resulting 1,4-diketones were obtained in moderate to excellent yields (49-98%) and good enantioselectivities (56-78% ee). For several Stetter products …
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Fluorescence Off-On Sensors for F-, K+, Fe3+, and Ca2+ Ions
… serving as the chromophore, and two 1,2,3-triazolium groups functioning as the signaling moieties, is described. The function of FS is established on the basis of deprotonation of the C-H bonds of 1,2,3-triazolium groups, which makes FS the first reported anion sensor based on the …
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Mechanism-Guided Studies of Brønsted Acid and Base Organocatalysis
… of aqueous pKa values of imidazolium and triazolium ions using a kinetic approach. Second-order rate constants for the deprotonation of these azolium ions by deuterioxide ion (kDO, M-1s-1) in D2O at 25 C were determined by 1H NMR spectroscopy. These kDO values could be used to calculate …
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Investigations into the Manipulation of 1,2,3-Triazoles and Towards an Asymmetric ‘Click’ Reaction of Meso Bis-Alkynes
… is then transformed to its corresponding triazolium salt, with the longer alkyl chains only giving 40-45% product. They are then reacted with potassium tert-butoxide to generate the 1,5-disubstituted 1,2,3-triazole in yields of 83% or above. The reaction steps were optimised to give a …
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Design, synthesis and fluorescent characterisation of 2,5-dihydro-1,2,3-triazines
… cycloaddition between 2,4,5-triphenyl-1,2,3-triazolium-1-arylaminide 1,3-dipoles and terminal alkyne propiolates. The initial cycloadduct undergoes a sigmatropic rearrangement followed by a ring expansion to generate the 2,5-dihydro-1,2,3-triazine fluorophore. The synthesis of …
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Preparación estereoselectiva de interesantes líquidos iónicos y carbamatos mediante procesos de resolución cinética y desimetrización enzimática
… García-Verdugo, V. Gotor-Fernández, ¿Enantiopure triazolium salts. Chemoenzymatic synthesis and applications in organocatalysis¿ ChemCatChem 2011, 3, 1921-1928. En el tercer capítulo, se ha llevado a cabo la síntesis de líquidos iónicos tricatiónicos y hexacatiónicos, y algunos de los resultados …