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Showing 1 to 20 of 35 for “"Palladium catalyst"”.
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Partial oxidation of methane over halogen modified palladium catalyst.
… temperature range of 390° to 510°C. The catalyst, 0.5% palladium supported on alumina, was modified by a constant and continuous supply of small amounts of chlorine, bromine and iodine compounds. The effect of various process variables, namely the weight ratio of halogen additive to …
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Palladium- and nickel-catalyzed C-N cross-coupling reactions featuring soluble organic bases
… Breaking the Base Barrier: An Electron-Deficient Palladium Catalyst Enables the Use of a Common Soluble Base in C-N Coupling Due to the low intrinsic acidity of amines, palladium-catalyzed C-N cross-coupling plagued continuously by the necessity to employ strong, inorganic, or insoluble bases. To …
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Ketone -Catalyzed Epoxidation of Alkenes With Oxone and Palladium -Catalyzed Biaryl Synthesis via Silacyclobutanes
… affected by the addition of ligands for the palladium catalyst. A wide range of electronically different and structurally diverse unsymmetrical biaryls have been prepared in good to excellent yields.
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Towards the total synthesis of Phacelocarpus-2-pyrone A: Novel 2-pyrone chemistry
… cross-coupling reactions using the interesting palladium catalyst, CatCat. Key findings in the studies towards the natural product include: i) the synthesis of two 6-alkyl-4-hydroxy-2-pyrone intermediates suitable for providing a synthetic platform for future work; ii) the first synthesis of a …
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Zur Palladium-katalysierten Dimerisierung von Acrylsäuremethylester
This work describes the optimisation of the palladium catalysed dimerisation reaction of methyle acrylate by using mono- and bidentate ligands and ionic liquids as solvent. Furthermore a biphasic reaction system is developed and applied to a continuos reactor. The activity of the Palladium catalyst …
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Investigation of the Steric and Electronic Properties of 3-Iminophosphine Ligands in Chelated Palladium Allyl Complexes for Use in the Regioselective Hydroamination of Allenes
A series of (3-iminophosphine)allylpalladium triflate complexes varying in both steric and electronic features was isolated and characterized. The propensity of the complexes in this series to regioselectively catalyze the hydroamination of 3-methyl-1,2-butadiene with aryl amines to form solely the …
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The synthesis & optimisation of irreversible ITK inhibitors as a potential new treatment for severe asthma
… inhibitors. This coupling required 30 mol % of palladium catalyst, which, on large scale, represents a significant amount of metal waste. The investigation of this coupling strongly suggested that the substrates involved in the reaction were poisoning the catalyst. The final results from this …
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Functional polybithiophenes: Novel syntheses approaches, characterization and application aspects
… dibrominated aryl monomers in the presence of a palladium catalyst to synthesize the corresponding polymers. This polymerization process was applied to the syntheses of functionalized polybithiophenes using 3-(I?-functionalized-hexyl)-5,5a??-dibromo-2,2a??-bithiophenes, …
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Tertiary alkylamines as effective directing groups for palladium-catalysed C(sp3)–H activation strategies
… reported to direct C–H cleavage on a series of palladium-catalysed reactions. The work reported in this dissertation describes the development of a new palladium-catalysed strategy towards the functionalisation of aliphatic tertiary amines. Methyl, methylene, and methine C–H cleavage have been …
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Polymerization and Isomerization of Olefins using Late-Transition Metal Complexes
… serve as efficient olefin polymerization catalysts. The mechanism of α-diimine-palladium and nickel catalyzed olefin polymerization is well understood. By understanding the fundamental steps of olefin polymerization, catalysts can be rationally designed to achieve a polymer with desired …
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Investigation of aryldimethylsilanolates in palladium-catalyzed cross-coupling reactions and development of chiral bis-hydrazone ligands for asymmetric aryl-aryl couplings
The preparation of biaryls by palladium-catalyzed cross-coupling of aromatic bromides and chlorides with alkali-metal salts (potassium and sodium) of aryl- and heteroarylsilanols has been developed. The critical feature for the success of this method is the use of …
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Late transition metal catalyzed C-N and C-C bond forming reactions
New methods for the palladium-catalyzed amination of aryl halides are described. Key to these is the development of new catalysts and reaction conditions for these transformations. Initially, P(o-tol)3 ligated palladium catalysts were investigated but gave way to systems that used chelating …
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Ligand-Driven Development of Pd-Catalyzed Nondirected C–H Activation of Arenes
… exploring the potential of dual-ligand enabled palladium-catalyzed aromatic C–H activation, this dissertation presents and discusses three research projects. The first project describes the development of a nondirected C–H olefination method for the late-stage installation of clickable alkyne …
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Polystyrene Hydrogenation in Supercritical CO2-Decahydronaphthalene Using Porous Catalysts
… used as the solvent for the polymer. Several palladium-based porous catalysts were identified for PS hydrogenation at 150oC. Relatively high degrees of hydrogenation were obtained with monometallic palladium catalysts for the reaction conducted in neat DHN. However, when either palladium …
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Rhodium-catalyzed Asymmetric Carbon-Carbon Bond Formation Leading to the Development of Rhodium/Palladium Multi-metal Catalysis
… alkenes and the subsequent use of rhodium and palladium catalysis in the development of domino reactions. The contents are divided into 4 chapters. Chapter 1 describes the rhodium-catalyzed asymmetric ring opening (ARO) of strained bicyclic alkenes using silyl enolates. The development of this …
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Novel palladium-catalyzed synthesis of 3-substituted indoles and its application toward the total synthesis of indolactam V
… was used to prepare 2-nitrostyrenes. Palladium catalyzed N-heteroannulation of 2-nitrostyrenes yielded indoles in 61--99%. For example, reaction of a 0.5 M solution of 1,1-dimethylethyl 2-(1-nitro-2-napthyl)propenoate (65) in N,N-dimethylformamide with carbon monoxide (4 atm), in the …
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Graphene-Supported Metal Nanoparticles For Applications in Heterogeneous Catalysis
… as an effective solid support for metal catalysts. The Nobel Prize in Physics for 2010 was awarded to Andre Geim and Konstantin Novoselov "for groundbreaking experiments regarding the two-dimensional material graphene". Microwave-assisted synthesis of various metallic nanostructured …
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Method Development Towards Catalytic Transformations of Reactive Intermediates
… towards heterocannabinoid species. Oxidative palladium (II) catalysis was employed to generate o-QM in situ via intermolecular activation of a styrene olefin. Though limited success was realized for the target compound, proof of mechanistic concept was accomplished when synthesis of chromans …
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Development of Methods for Boron Reagents
… of utilizing a diboron reagent mediator in the palladium-catalyzed hydrogenation of allenes. In the presence of a palladium catalyst, tetrahydroxydiboron and stoichiometric water, allene semireduction proceeds in good yield. This semireduction is regioselective for the terminal alkene and …
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Polyfluorinated Aromatic Systems for Liquid Crystal Display Applications
… systems are compatible substrates for palladium–catalysed Suzuki–Miyaura and Heck–type cross–coupling reactions involving C–F bond activation. Cross–coupling reactions of pentafluoronitrobenzene with a range of boronic acids and protected ester equivalents bearing electron–withdrawing …
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