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Showing 1 to 16 of 16 for “"Katalytische Hydrierung"”.
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Katalytische Hydrierung in Mehrphasensystemen auf Basis von ionischen Flüssigkeiten und Kohlendioxid
Carbon dioxide (CO2) and ionic liquids (ILs) have been intensively studied as solvents in catalysis. The combination of ILs and CO2 and its interaction with third components has attracted only sparse interest in research. In the literature, the IL/CO2 system is discussed as a promising technique …
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Synthese von 9,11-Drimenylchinonen und -hydrochinonen
… Benzylalkoholen 12a,b gekuppelt wurde. Katalytische Hydrierung von 12a,b an Palladium auf Kohlenstoff ergab die gewünschte Zwischenstufe 5a,b. Acetylierung von 5a,b zu 17a,b und anschließende CAN-Oxidation führte zu dem o-Dimethoxybenzochinon 19a,b. Durch Umsetzung des o-Dimethoxychinons …
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Ex-Chiral-Pool-Synthese von 5-Aminopiperidylessigsäuren über eine Tandem-Wittig-1,3-dipolare Cycloaddition
… des a,b-ungesättigten Esters 74. Über eine katalytische Hydrierung des Diazoesters 76 konnte man einen sehr guten Zugang zu den trans-konfigurierten Piperidylacetaten 2R-78 etablieren. Das andere Diastereomer 2S-78 sollte nach Stickstoffextrusion aus 76 durch diastereoselektive Hydrierung …
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Synthese, Stereochemie und pharmakologische Charakterisierung von 3,7-Diazabicyclo[3.3.1]nonan Derivaten als selektive kappa-Agonisten
… werden. Der 1,5-Dibenzylester 25 konnte durch katalytische Hydrierung mit Pd/C als Katalysator in EtOAc zur freien 1,5-Dicarbonsäure 26 umgesetzt werden. Die Triole 56-62 wurden ausgehend von den 9-Oxo-BNDS HZ2, 3FLB, 21-24, 28, 33 in einer Eintopfsynthese mittels NaBH4 in THF/MeOH durch …
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Zur Mikro- und Makrokinetik mehrphasiger heterogen-katalysierter Reaktionssysteme : Untersuchungen am Modellsystem der Ni-katalysierten Hydrierung von 1-Octen
Heterogeneous catalysis based upon multiphase reactions is a very important issue in the chemical industry. Various mass transfer resistances (gas-liquid, liquid-solid, pore diffusion) occur in such systems. This results in the fact that the effective rate of reaction is much lower than the …
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Synthesis, characterization and modification of carbon nanomaterials
The main objective of the present thesis is to deepen the understanding of the mechanisms involved in catalytic growth of carbon nanotubes (CNT) and related processes, such as the catalytic hydrogenation, and to use this knowledge to optimize the experimental approaches in order to gain better …
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Hydrierung im invertierten Zweiphasensystem scCO 2/H 2 O
Catalysis using an inverted scCO2/H2O biphasic system where the catalyst is immobilized in scCO2 as stationary phase and the substrate and product are contained in the aqueous phase, offers an interesting alternative to classical biphasic systems and enables the conversion of polar substrates, …
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Optically active [(eta 6 -arene)Cr(CO) 3]-based diphosphines : synthesis and application in asymmetric homogeneous hydrogenation
Chiral diphosphines have become an important class of ligands for asymmetric catalysis. It is the success itself of enantioselective catalysis that has enhanced the demand for new chiral ligands for essentially two reasons. The first one is that no class of ligands can be considered universal …
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Allylcalcium complexes : synthesis, reactivity and application in homogeneous catalysis
The main objective of the present work is to study preparation, coordination behavior and basic reactivity patterns of allylcalcium compounds. Examples for catalytic reactions of the resulting calcium compounds are given to evaluate the scope of applications. The first part describes the isolation …
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Chirale Phosphortriamide und Phosphin-Phosphoramidite als Liganden für die asymmetrische Katalyse
Asymmetric catalysis with transition metal complexes containing chiral ligands is an efficient tool for the synthesis of enantioenriched compounds, which can be used as active pharmaceutical ingredients, agrochemicals, flavors or fragrances. The development of novel chiral ligands plays a major …
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Selektive Hydrierung biogener organischer Disäuren mit Rutheniumphosphinkatalysatoren
In the scope of this work the hydrogenation of diacids was investigated in depth on the example of itaconic acid. Rutheniumcatalysts with phoshineligands were stable and active hydrogenation catalysts. Mono- and bydentate ligands catalyse the conversion towards the 2- and …
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Axial chirale Phosphite als Liganden in der enantioselektiven Rhodium-katalysierten Hydrierung
In the pharmaceutical and agrochemical industry enantiomerically pure substances become more and more important as drugs or chiral building blocks. The Rhodium-catalyzed hydrogenation is a very effective way to produce such enantiomerically pure substances. Activity and selectivity of the …
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Über die Entwicklung neuer Methoden zur N-Arylierung von Sulfoximinen und die Synthese von Diarylphosphinylsulfoximinen als Liganden in der asymmetrischen Metallkatalyse
In this work, new methods for the N-arylation of sulfoximines with various aryl sources have been developed. For the first time, aryl boronic acids can be used as aryl sources with ready available copper salts as catalysts. These cross coupling reactions can be performed under mild conditions at …
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Nanopartikuläre Katalysatoren und neue katalytische Anwendungen auf Basis der Metalle Rhodium und Cobalt
Within this work new poly(ethyleneglycol)-stabilised nanoparticles should be synthesised and tested in various catalytic reactions, as there are hydrogenation and C-C bond forming reactions (Pauson Khand reaction PKR). Additionally an effective protocol for the separation of the catalyst from the …
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Chirale ionische Flüssigkeiten in der homogenen Katalyse
The aim of asymmetric synthesis is to produce enantiomerically enriched compounds, which are for example important for pharmaceutical or agrochemical commodities. Different methods can be applied to achieve this: the separation of racemic compounds, the use of chiral substrates or the application …