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Showing 1 to 20 of 23 for “"DBU"”.
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Effect of Amines as Corrosion Inhibitors for a Low Carbon Steel in Power Industry
… amines in power industry, including morpholine, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), and DMA (dimethylallylamine) were evaluated for their effect on AISI 1018 steel at 250oF. Samples were exposed to an autoclave containing amine added aqueous solution at pH of 9.5 for 1, 2, 4, 6, 8, and 12 …
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Asymmetrische Weitz-Scheffer-Epoxidierung mit optisch aktiven Hydroperoxiden oder Phasentransferkatalysatoren
… aktiven Hydroperoxiden I und den Basen KOH oder DBU als Katalysatoren Acetonitril bei –40 °C möglich ist. Dabei bildet sich das (alphaS,betaR)-Epoxid IIIa in 51 Prozent ee. Im Gegensatz dazu wird in Toluol bei 20 °C mit der Base DBU das entgegengesetzt konfigurierte (alphaR,betaS)-Epoxid IIIa in …
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Removal of nitrogen containing hydrocarbons from wastewater by catalytic and non-catalytic hydrothermal oxidation, in sub- and supercritical conditions
… oxidation of 1,8 diazabicyclo[5.4.0]undec-7-ene (DBU), a toxic nitrogen-containing organic compound by different processes is presented here. Subcritical experiments (wet air oxidation (WAO) and catalytic wet air oxidation(CWAO)), were conducted in a batch reactor and supercritical water oxidation …
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Formation and Quantification of Corrosion Deposits in the Power Industry
… on corrosion inhibition mechanismsof a new amine DBU (1, 8-diazabicyclo [5.4.0] undec-7-ene). Electrochemical impedance spectroscopy and polarization curves were used to study the interaction mechanism between DBU solution and inconel alloys 600 and 690 at steamgenerator operating temperatures and …
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Bis-and tris (amidine) fluoroboron cations and related systems studies by Multinuclear NMR and fast atom bombardment mass spectometry
… out. 1,8-Diazabicyclo [5,4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4,3,O]non-5-ene (DBN), extremely strong organic bases, were introduced into the fluoroboron cation systems and induced a complicated redistribution reaction in the D/BF3/BC13 systems. The result was the formation of all …
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Enantioselective synthesis of alkenyl aziridine carboxylates and 4-phenylsulfenyl prolines
… salts (method B) upon treatment with DBU. Their application to the asymmetric aziridination of N-tert-butyl-sulfonyl imino ester, generated either in situ (method A) or externally added (method B), gave the corresponding alkenyl aziridine carboxylates with medium to high …
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Advances in palladium-catalyzed carbon-nitrogen bond forming processes
… and amines using the soluble amine bases DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or MTBD (7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene) and a catalyst system consisting of Pd2dba3 and ligands (XantPhos, 2-dicylcohexylphosphino-2',4',6'-triisopropyl-1,1 '-biphenyl (XPhos) and …
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New CO₂ chemistry for fine chemical synthesis
… a primary or secondary amine in the presence of DBU, and reaction of the resultant carbamate salt with triphenylphosphine and chlorobenzotriazole (BtCl) to produce Bt ureas in moderate to high yields. The Bt group may serve as a leaving group in nucleophilic substitution reactions, therefore it …
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Synthesis of 4-Azidocoumarins and Their Use in Copper-Catalyzed Azide-Alkyne Cycloaddition reactions
… (BOP), and 1,8-diazabicycloundec-7-ene (DBU) as the base, in tetrahydrofuran (THF) solvent. The 4-benzotriazolyloxy coumarins were converted to the 4-azidocoumarins by reaction with sodium azide (NaN3), and the overall process was simplified to a one-pot, two-step process. The methodology …
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Application of sulfonimidoyl substituted allyltitanium (IV) complexes to the asymmetric synthesis of alkenyloxiranes, 2,3-dihydrofurans, tetrahydrofurans, unsaturated proline analogues and allylic alcohols
… group follwed by Cl substitution, and subsequent DBU-mediated, intramolecular, nucleophilic substitution afforded the optically-pure proline derivatives in medium to high yields. An asymmetric synthesis of allylic alcohols from allylic sulfoximines and aldehydes is described in chapter 4. …
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Ionic Liquids in the Chemical Valorisation of Pulps and in their Chemical Analyses
… such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) with dimethylsulphoxide (DMSO), which resulted on the discovery of the unexpected reactivity of 1,1,3,3-tetramethylguanidinium acetate ([TMG][OAc]). Furthermore, this investigation led us to the design and synthesis of a novel task-specific …
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Asymmetrische Synthese 3-substituierter 4-Methylenproline und Untersuchungen zur Metathese mit vinylischen Sulfoximinen
… aminosulfoxonium salt were cyclized with KF or DBU to the same 3-substituted 4-methylene prolin in yields between 54 and 78%. The sulfinamide splitted off was isolated in yields greater than 81% and with an enantiomeric excess of 99%. This sulfinamide may be converted to enantiomerically pure …
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A study of Śāntarakṣita's Madhyamakālaṃkāra
… the major Tibetan commentary on this work, the dBu-ma rgyan gyi rnam-bshad 'jam-dbyangs bla-ma dgyes-pa'i zhal-lung of Mi-pham rgya-mtsho (1846-1912). The Introduction surveys the history of the text and discusses some of the reasons for its neglect among traditional and modern scholars, this …
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Studies in Xanthone chemistry
… has been investigated. Treatment with DBU in toluene led to 4-(2-hydroxybenzoyl)- 9H-xanthen-9-ones, whereas with potassium carbonate in acetone novel 5H,13H-[l]benzopyrano[2,3 -ajxanthen -5, 1 3-diones were obtained. The mechanism of formation for these compounds is discussed.
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Catalytic supercritical water oxidation of nitrogen-containing organic compounds
… toxic nitrogen-containing organic compounds (DBU and quinoline) are presented. The reactions were studied in a tubular xed-bed reactor over three catalysts: Pt/Al\(_2\)O\(_3\), CuO/Al \(_2\)O\(_3\) and MnO\(_2\)/CuO. The effect of operating conditions, namely temperature, pressure, oxygen …
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Asymmetrische Synthese Delta 3a,4 -ungesättigter bicyclischer Prolin-Analoga und Festphasensynthese mit vinylischen Sulfoximinen
… nucleophilic substitution with either DBU or lithium-tert-butyl amide in good yields of 76-81% to D3a,4-unsaturated bicyclic proline analogues. The cyclization reaction starts with a base induced isomerization of the 1-alkenyl dimethylamino sulfoxonium salts to the novel 2-alkenyl …
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Synthesis Of 1,4-Triazolyl Combretacoumarins As Potential Anticancer Agents
… hexafluorophosphate (BOP) and DBU, in MeCN. Then, NaN<sub>3</sub> is added in order to displace the BtO<sup>–</sup> at the C-4 position, leading to the desired 4-azidocoumarins. The mechanism of the formation of <em>O</em><sup>4</sup>-(benzotriazolyl) derivative of …
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Síntese e estudo do mecanismo de inibição do transporte de elétrons fotossintético de novos análogos aos rubrolídeos e estudos sintéticos dirigidos para o furanocembranolídeo (-)-deoxipukalídeo
… DIPEA e TBDMSOTf para condensação aldólica e DBU, sob refluxo, para reação de eliminação. Para síntese dos compostos 3-bromo-4-aril-5-(arilideno)furan-2(5H)-ona, 3,4- dibromofuran-2(5H)-ona foi submetida primeiramente a reação de acoplamento cruzado de Suzuki-Miayura e posteriormente a reação …
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Darstellung, Reaktivität und Struktur von Mono- und Di-Manganiophosphonium Salzen sowie Lewis-Säure-Base-Addukte von Ferraten mit metallorganischen Lewissäuren
… da die zunächst eingesetzte Base DBU nur äußerst schlecht abgetrennt werden kann. Bei Verwendung der festen Base DABCO konnte diese durch mehrmaliges Waschen mit n-Hexan/CH2Cl2 vollständig entfernt werden und 7 sauber erhalten werden. Eine Übersicht der bisher behandelten …
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Μελέτη φωτονικών ιδιοτήτων οργανικών ευαισθητοποιητών με δυνατότητα εφαρμογής σε φωτοβολταϊκά κελιά
… μιας ισχυρής βάσης με την κωδική ονομασία DBU. Με αυτό τον τρόπο πραγματοποιήθηκε μελέτη των σταθερών ιόντων σε διάλυμα τόσο με φασματοσκοπία σταθερής κατάστασης όσο και χρονικής ανάλυσης. Σε σταθερή κατάσταση τα φάσματα των ιόντων που παράχθηκαν σε διάλυμα έδειξαν απόλυτη σύμπτωση με τα …
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