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Showing 1 to 20 of 153 for “"palladium-catalyzed"”.
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Palladium-catalyzed PMHS reductions of imines
We explored the Pd-catalyzed reductions of imines using polymethylhydrosiloxane (PMHS) in the presence of aqueous KF. This methodology developed by our group facilitates the reduction of nitrogen-containing functional groups under mild conditions and short reactions times. To the best of our …
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Mechanistic studies on palladium-catalyzed coupling reactions
… information about the individual steps of palladium-catalyzed coupling reactions. In one case, the oxidative addition of PhX (X = I, Br, Cl) to the complexes Pd(PtBu3)2 (1), Pd(1-AdPtBu2)2(2), Pd(CyPtBu2)2 (3), and Pd(PCy3)2 (4) (1-Ad = 1-adamantyl, Cy = cyclohexyl) was studied to determine …
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The palladium-catalyzed synthesis of organic amines
… ether (DPEphos), in combination with palladium acetate, forms a highly active catalyst system for the coupling of anilines with aryl bromides. The bisphosphine is easily prepared in large quantity and at low cost by a known procedure. The catalyst system is effective in coupling …
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Palladium-catalyzed reactions of ammonia, carbon monoxide, and cyanide
… from a series of bisphosphine-ligated arylpalladium(II) parent amido complexes countered several established trends. In contrast to arylamido and alkylamido complexes of the aromatic bisphosphines DPPF and BINAP, parent amido complexes did not form or undergo reductive elimination of …
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Palladium catalyzed cross-coupling reactions of allyl- and vinylsilanes
Palladium-catalyzed cross-coupling of γ-substituted allylic silanolates with aryl bromides was investigated. It was discovered that γ-selectivity is heavily influenced by the substituents at silicon. It is proposed that undergoing an activated pathway significantly lowers the selectivity of the …
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Advances in palladium-catalyzed carbon-nitrogen bond forming processes
Chapter 1. Microwave-assisted, palladium-catalyzed C-N bond-forming reactions with aryl/heteroaryl nonaflates/halides 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 …
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Palladium Catalyzed Hydrodechlorination of 4-Chloroanisole in Phosphonium Ionic Liquids
… as a model compound. In this fundamental study, palladium-catalyzed dechlorination of chloroanisole was studied in ionic liquids (ILs), where the catalyst was expected to be more stable than in methanol, the previously used solvent. This thesis describes the hydrodechlorination efficacy and …
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Palladium catalyzed carbon-carbon bond formation at carbon-hydrogen bonds
The biaryl core has been identified by medicinal chemists as a privileged structure in pharmaceutical compounds as it is found in 4.3% of all drugs. For over a century, synthetic chemists have sought new methods for their preparation. Breakthroughs in synthetic catalytic methodology over the past …
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Improving Palladium Catalyzed C–H Activation Methodologies Towards Industrial Applicability
With the common goal of addressing C–H activation challenges in order to accelerate its use in industrial applications, in the dissertation presented herein, three projects will be presented and discussed. In the first chapter, we decided to tackle the concerns behind high catalyst loadings and …
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Mechanistic studies on palladium-catalyzed carbon-nitrogen bond forming reactions
… calorimetry was used to explore the rate of the palladium-catalyzed coupling of 4-t-butylbromobenzene and morpholine using the ligand Xantphos at varying palladium to ligand ratios. It was found that catalyst activity is dramatically dependent on the concentration of ligand relative to palladium, …
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Mechanistic studies on palladium-catalyzed C-N cross-coupling reaction
Mechanistic studies on the palladium catalyzed C-N bond-forming reaction were carried out to generate a more complete understanding of the catalytic cycle. To understand this reaction, several kinetic studies employing simple aryl halide and amine coupling partners were performed to elucidate …
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Palladium-catalyzed C-N and C-O cross-coupling reactions
… describes a general method for the of the Pd-catalyzed N-arylation of hindered [alpha],[alpha],[alpha]-trisubstituted primary amines. The reaction utilized catalysts based on two biaryl phosphine ligands, which were developed via kinetics-based mechanistic analysis and rational design. These …
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Synthesis of α, β-Substituted Alkenylphosphonates from α-Phosphonovinyl Triflates: I) Palladium Catalyzed Suzuki-Miyaura Cross-coupling with Aryl Boronic Acids II) Palladium Catalyzed Reduction
<p>Alkenylphosphonates (vinylphosphonates) are important targets for R & D because they have interesting chemical, biological and pharmacological properties. Vinylphosphonates are used in synthesis, polymer applications, and have demonstrated potential as anticancer and antimicrobial agents.</p> …
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New Methods for Palladium-catalyzed Decarboxylative Benzylation, Arylation and Dearomatization Reactions
… endeavor in organic synthesis. In this regard, palladium-catalyzed decarboxylative cross-coupling has significant potential as a waste-free reaction manifold with increased functional group tolerance due to the avoidance of preformed organometallics and basic reagents. Since the initial reports …
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INVESTIGATIONS IN IRON, COPPER, AND PALLADIUM –CATALYZED C-H BOND FUNCTIONALIZATION
Transition metal-catalyzed functionalization of C-H bonds has been used as a powerful tool for the construction of C-C and C-heteroatom bonds. Within this dissertation, methods that allow functionalization of C-H bonds via iron and copper catalysis have been developed. Additionally, …
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Palladium-Catalyzed Alkenylsilanol Cross -Coupling Reactions: Method Development and Mechanistic Analysis
… (KIE) studies. This provided evidence for either palladium-olefin complexation or a Heck-type carbometalation as the turnover-limiting step for these cross-coupling reactions.
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Development and application of palladium-catalyzed carbon-nitrogen bond forming reactions
Chapter 1. Pd-Catalyzed Cross-Coupling of a-Substituted Optically Active Amines with Aryl Bromides. The palladium-catalyzed coupling reaction of enantiomerically enriched a-substituted amines with aryl bromides is described. The choice of ligand in the palladium-catalyzed coupling reaction is …
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Palladium-catalyzed C-C, C-N and C-O bond formation
New methods for Pd-catalyzed cross-coupling reactions of aryl halides or arenesulfonates are described. Key to the success of these transformations is the proper choice of ligand and reaction conditions. Palladium catalysts supported by bulky, monodentate phosphine ligands with a biaryl backbone or …
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I. Progress Toward Leiodelide A II. Palladium-Catalyzed Reactions of Enol Ethers
… developed by our laboratory to allow for palladium-mediated couplings to form 2,4- and 2,5-disubstituted oxazoles. Unfortunately the macrolactone could not be closed using Mitsunobu macrolactonization conditions, but an alternate route has been devised in order to complete the total …
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Dearomative functionalization of simple arenes: Reduction and palladium-catalyzed syn-1,4-aminofunctionalizations
… protocol was established using palladium complexes as catalysts and with carbon-, nitrogen-, and oxygen-based nucleophiles. The key features of these processes compared to existing dearomatization reactions are: 1) amenable aromatic substrates encompassing a wide range of …
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