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Showing 1 to 19 of 19 for “"Palladium(0)"”.
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Development of Palladium(0)-Catalyzed Suzuki Cross-Coupling Polymerizations
… tolerance to solvents and reaction conditions, palladium(0)-catalyzed cross-coupling reactions would give us a good chance to achieve the goal. Thus, my Ph. D dissertation research projects focused on developing Pd(0)-catalyzed Suzuki cross-coupling polymerization reactions including controlled …
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Rhodium-Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes and Palladium-Catalyzed Carbon-Halogen Bond Forming Reactions
… bond constitutes the first step of nearly all palladium(0)-catalyzed cross-couplings. Conversely, reductive elimination from palladium(II) to yield an organohalide product represents a rare and often thermodynamically unfavoured process. The next two chapters address challenges in the synthesis …
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Palladium-katalysierte kinetische Racematspaltung allylischer Carbonate mit S-Nukleophilen und enantioselektive Umlagerung allylischer O-Sulfinate : asymmetrische Synthese von allylischern Sulfiden und Sulfonen
The palladium(0) catalyzed reactions of symmetrically disubstituted racemic allylic carbonates, being either cyclic or acyclic, with 2-pyrimidinethiol in the presence of N,N'-(1R,2R)-1,2-cyclohexanediyl-bis[2-(diphenylphosphino)-benzamide] BPA as ligand proceed with excellent levels of …
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N-Phosphino-pyridyl Imines: Flexible, Multi-functional Reagents
… in chapter II. The molecular structures of their palladium dichloride complexes are presented, highlighting the effect of differing substituents on framework 1 upon the geometry of the complexes. The chemistry surrounding a novel equilibrium between two valence tautomers prepared from reaction of …
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Sequential cycloadditions for the synthesis of taxoid mimics and stereoselective synthesis of tamoxifen analogues via a new carbomagnesiation-palladium coupling reaction
… on microtubules. A sequential carbomagnesiation-palladium (0) coupling reaction was investigated. Treatment of a propargyl alcohol with vinyl magnesium chloride generated a magnesium-chelate intermediate, which was capable of undergoing a palladium-catalyzed cross coupling with aryl halides. The …
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Part 1: Progress Toward the Total Synthesis of Platensimycin. Part 2: Aromatic Ions: Carbon-Based Nucleofuges and Chiral Cyclopropenones and Formamides
… A revised strategy was employed using a palladium(0) catalyzed Heck cascade and palladium(II) catalyzed alkoxypalladation. The second chapter describes the development of a carbon-based nucleofuge. A substituted cyclopentadienyl anion served as a competent leaving group in the Tsuji-Trost …
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Mild [Pd(OAc)2/PPh3] catalyzed cyclization reactions of N-Alkyl-2-vinylazetidines with heterocumulenes.
… and highly regioselective methods for the palladium(0)-catalyzed insertion of heterocumulenes into these substrates have been established, employing a Pd(OAc)2/PPh3 catalyst system under very mild conditions. An assortment of tetrahydro-pyrimidin-2-ones, tetrahydro-pyrimidin-2-imines, and …
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Palladium-katalysierte enantioselektive Umlagerung allylischer O-Thiocarbamate
… The aim of the project was the examination of Palladium(0) catalyzed rearrangements of allylic thiocarbamates. Influences of the allylic moity ant the substituents at the nitrogen were investigated in respect to reactiontimes, enantio-meric excesses of the products and used amounts of catalyst. …
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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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Synthetic Studies Towards the Crisamicins
… of bis-7- acetylnaphthalene 1.268 using a palladium(0)-mediated Suzuki-Miyaura homocoupling of the key triflate 1.269 (prepared in 10 steps from vanillin 1.271) using bis(pinacolato)diboron 1.179. This coupling method successfully afforded binaphthyls 2.8b and 2.8d which were subjected to …
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Phosphate Tethers in Synthesis: The Total Synthesis of Dolabelide C.
… as a leaving grouping for a regioselective palladium(0)-catalyzed hydride opening. Upon removal of the phosphate tether, the C1-C14 subunit of dolabelide C was completed in six subsequent steps. Studies toward the C15-C30 subunit of dolabelide C also utilized the bicyclic phosphate tether …
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Studies In the Optimization of the Suzuki-Miyaura Reaction
… to which the supposed catalysts, bisphosphinepalladium(0) complexes, are actually formed from the variety of popular precatalysts used. There is in fact little evidence that these precursors produce bis-ligated Pd(0) complexes and it is possible that the rate limiting factor may be catalyst …
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Synthesis and Application of Air-Stable Secondary Phosphine Oxide, Oxime, and Amine-Phosphine Palladium(II) Complexes in Transfer Hydrogenation and Cross-Coupling Reactions
… of ligands have been identified and employed in palladium-catalyzed reactions. These systems are believed to promote their respective reactions through a monoligated palladium(0) species. Our work focused on the development of precatalysts with an established 1:1 L:Pd ratio. Specifically, we were …
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Palladium and platinum complexes of trans-coordinating bidentate phosphine ligands
… cis- and trans-positions. Preparations of palladium (0) and platinum (0) complexes gave, in low yield, solids which analysed for [Pd(dPh) 2 ]; [Pd(PP)(H 20)] and [Pt(Pp)]. The solids were stable in air for short periods of time, but in organic solvents they appeared to undergo changes, …
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Design and synthesis of rotational analogues of estradiol
… the corresponding dienyl triflate, followed by palladium(0) mediated deoxygenation to afford the 14, 16-diene. Of these two methods, only the latter was successful, as the tosylhydrazone of 3-methoxyestra1,3,5(10), 15-tetraen-17-one could not be synthesised. In the second phase of the work~ …
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Control of regioselectivity:oxidation and deprotection
Palladium is a highly versatile metal, capable of catalysing oxidations, reductions and a myriad of organic transformations. The inorganic chemistry of palladium, and the relation of this to the catalytic activity of the metal, is briefly discussed. A short survey of the range of palladiumcatalysed …
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Synthesis and reactivity of alpha-trialkylsilyl alpha-amino acids
… remained unsuccessful. Hydrogenation over palladium(0) allowed exclusively the formation of the bi-deprotected alpha-silyl alpha-amino acetic acid. The alpha-silyl alpha-amino acid core could become a substructure of a more complicated structure, as for example of a modified Matrix …
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Palladium(II) catalyzed allylic C-H alkylation reactions
… This work describes the discovery of the first palladium(II)-catalyzed allylic C-H alkylation reaction. Allylic alkylation has long been performed by palladium(0) catalysis with allylic oxygenate starting materials. In contrast, this method proceeds directly from the readily accessible, …
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Supported catalysts, from polymers to gold nanoparticles supports
… main catalysts that are used in this thesis, the palladium pincer complex and the palladium N-heterocyclic complex. In chapter 3, the synthesis of a soluble polymer supported catalyst is described. The polymer chosen for the study is poly(norbornene), and the catalyst is a 1,3-disubstituted …