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Showing 1 to 20 of 12114 for “"Carbon"”.
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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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Development of new transition metal-catalyzed carbon-fluorine, carbon-nitrogen, and carbon-carbon bond forming processes
Chapter 1. Palladium-Catalyzed Fluorination of Cyclic Vinyl Triflates: Dramatic Effect of TESCF₃ as an Additive A method for the synthesis of cyclic vinyl fluorides with high levels of regiochemical fidelity has been achieved by Pd-catalysis employing a new biarylphosphine ligand and TESCF₃ as a …
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HYPERVALENT IODINE METHODS FOR CARBON–NITROGEN AND CARBON–CARBON BOND FORMATION
Carbon-carbon and carbon-nitrogen bond forming events are essential in chemistry. Although numerous stoichiometric/catalytic methods provided elegant and powerful solutions enabling those processes, the use of scarce/toxic reagents and harsh conditions is still ubiquitous in this field. As a …
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Post-Carbon Seoul: Low-Carbon Interventions for a High-Carbon Housing Stock
… strategies like phased interventions and low-carbon materials such as mass timber. The analysis reveals that this alternative extends building lifespan and achieves substantial carbon reductions by preserving the embodied carbon within existing structures. It offers long-term financial …
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Carbon-Carbon Bond Formation Via o-Lithiointermediates
… fractional equivalents of TMEDA in hydrocarbon solvents at 60°C, o-lithiation of anisole and dimethylaniline can be effected in >95% yields. The first step in the DoM process involves preparation of solid samples of these o-lithiointermediates. Completing the sequence, the second step …
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1,6-Eliminations with two carbon-carbon cleavages
Made available in DSpace on 2014-12-09T17:35:27Z (GMT). No. of bitstreams: 1 6607728.pdf: 5376218 bytes, checksum: bd508fed35fcb7307a8f53940d48345b (MD5) Previous issue date: 1966
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Selective Borylations of Carbon-Carbon pi-Bonds
… reaction, which is used to generate carbon-carbon bonds under mild conditions. Because of the versatility of organoboron reagents, methods to selectively install boron remains crucial. Boron containing compounds have recently garnered significant interest in the medicinal chemistry …
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(N-heterocyclic-carbene)Copper(I)-catalyzed carbon-carbon bond formation using carbon dioxide
… and the product silyl acrylate. The use of silylcarbonate salts to desylilate the product enhanced yield. In addition, silylcarbonates can also serve as a source of CO2.
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Recent advances in palladium-catalyzed carbon-carbon and carbon-boron bond forming processes
Chapter 1. Highly active and efficient catalyst systems derived from palladium precatalysts and monophosphine ligands for the Suzuki-Miyaura cross-coupling reaction of heteroaryl boronic acids and esters has been developed. This method allows for the preparation of a wide variety of heterobiaryls …
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Recent advances in copper- and palladium-catalyzed carbon-heteroatom and carbon-carbon bond-formation
Metal-catalyzed nucleophilic substitution reactions of aryl halides have become one of the most valuable and useful classes of reactions developed in the last 30 years. Foremost among these processes are the classes of palladium- and copper-catalyzed reactions, which employ heteroatom-based …
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Brønsted Acid Catalyzed Carbon-Carbon Bond Forming Reactions
… this research project will unveil new asymmetric carbon carbon bond forming reactions between substrates hitherto unexplored with Brønsted acid catalysis. It has been established that strong Brønsted acids, such as phosphoric acids, are capable of mediating highly selective transformations …
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Thermal stresses in coatings on carbon-carbon composites
… stresses in oxidation protection coatings on carbon-carbon composites. Multilayer coatings with each layer of coating applied at a different temperature, and gradient coatings with continuously varying properties through the thickness of the coating were considered. Particular emphasis was on …
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Micromechanics of crenulated fibers in carbon/carbon composites
… transverse strain and to a temperature change in carbon/carbon composites is examined using the finite element method. Stresses at the interface of both fully bonded and fully disbonded fibers having two crenulation amplitudes and with two fiber volume fractions are presented. In each case, these …
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Scope and stereochemistry of carbon-carbon bond formation via addition of carbon nucleophiles to nitrones
… t-butyl acetate. However, similar additions of carbon nucleophiles to 4-t-butyl-2,3,4,5-tetrahydropyridine N-oxide afforded only the trans isomer from axial addition in moderate yields (60-68%). The stereoselectivity in these endocyclic nitrone additions can be explained by a stereoelectronic …
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Carbon Dioxide Capture: Using Activated Carbon From Chicken Waste
Carbon Dioxide (CO2) emission from hydrocarbon fuel combustion is becoming a serious concern because it is the main contributor to greenhouse gas which causes global warming. Activated carbon sorbents have been used widely in various gas-phase and/or liquid-phase separation. Currently activated …
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Novel method for carbon nanofilament growth on carbon fibers
Carbon nanofilaments were grown on the surface of microscale carbon-fibers at relatively low temperature using palladium as a catalyst to create multiscale fiber reinforcing structures with potential applications in structural composites. Employing a relatively new method, in which carbon …
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Multiscale Numerical Modeling and Characterization of Carbon/Carbon Composites
<p>Carbon/carbon composite is a high-performance material with a unique set of physical and thermo-mechanical properties making it irreplaceable for severe environment aerospace applications. Its complex hierarchical microstructure presents materials scientists and engineers with substantial …
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