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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 92 for “"C–H activation"”.
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C-H Activation of Functional Materials
… comprises three projects on the theme of C-H activation for the synthesis of functional materials. Chapter 1 describes the development of gamma C-H carbonylation of free aliphatic secondary amines to form secondary lactams. The diastereoselectivity of the reaction was found to be significantly …
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Improving synthetic efficiency through C—H activation
Selective C—H activation methods provide a complementary approach for synthesizing complex small molecules, which traditionally are constructed by chemists using C—C bond forming reactions to join preoxidized fragments. Furthermore, the strategic application of C—H activation reactions has …
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Palladium and manganese catalysis in C-H activation
Direct arylation via C-H activation has emerged as a powerful tool for the construction of new aryl-aryl bonds and provides an alternative to classical cross coupling procedures. Double C-H activation in particular, represents a more sustainable approach in terms of waste, cost and atom economy. …
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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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Design of flow processes for C–H activation-type reactions
… bond forming reactions, the uptake of C–H activation in fine chemical manufacture is slow. Part of the reason for this deficiency is limited mechanistic understanding of these complex reactions. This can preclude industrial applications of either batch or continuous C–H activation …
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Intermolecular C-H activation effected by CP*W(NO)-containing complexes
… chlorobenzene reaction reveal that the ortho-C-H-activation product is preferentially formed via thermal isomerization from the meta / para-C-H-activation isomers. Reactions between Cp*W(NO)(CH₂EMe₃)Cl (E = C or Si) and a variety of bis(allyl)magnesium reagents lead to the expected formation of …
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Allylic C—H activation to access anti-1,3-amino alcohol motifs
1,3-Amino alcohols are common motifs in a variety of biologically active molecules including antivirals, antibiotics, antifungals, and various alkaloids. Due to their prevalence and utility as synthetic intermediates, a variety of methods have been developed to access these motifs in a …
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Ligand-Driven Development of Pd-Catalyzed Nondirected C–H Activation of Arenes
… 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 motifs into (hetero)arenes. Using a …
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Interplay of Transition Metals and Noncovalent Interactions in C–H Activation Catalysis
Selective C–H activation is crucial for the synthesis of bioactive molecules and natural products, and plays an important role in pharmaceutical industry, medicinal chemistry, and the materials industry. While synthetic routes to activate unreactive C–H bonds require harsh conditions and usually …
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Studies in iridium and manganese catalysis in C-H activation and reductive transformations
… is a critical tool for organic synthesis. C−H activation has emerged as an effective means to access diversified heteroaromatic motifs. In particular, iridium-catalysed C−H borylation has proven a useful means of heteroarene functionalisation, due to its ability to produce highly versatile aryl …
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Application of asymmetric C-‐H activation to the synthesis of Planar Chiral Catalysts and Ligands.
… for a number of years. The use of C-‐H activation to synthesise such compounds has been a relatively new development. The work within this thesis attempts to develop on known protocols devised by Richards et al. for the generation of enantioenriched planar chiral palladacycles.1. The …
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Synthetic diversity in C-H activation: development of selective and efficient C-H functionalization reactions
… to effect a divergent intramolecular allylic C−H activation reaction to generate two different products from a common starting material. By taking advantage of the inherent reactivity of a urea nucleophile, two medicinally important moieties are formed and further elaborated to furnish …
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Chirality Transfer in Acyclic Allylic Systems and New Pd-Catalyzed Heck Reaction/C-H Activation Cascades
… underwent, in the absence of nucleophile, a C-H activation reaction, leading to spiro cyclopropyl compounds.
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C-H activation: oxidative addition to an iridium(I) center and reactivity of the resulting iridium(III) species
Thermal reactions of the iridium complex, [Ir(COD)(PMe₃)₃]Cl (COD=1, 5 Cyclooctadiene), with benzene, benzaldehyde, pyridine, and furan yield the C-H addition products of mer-(Me₃P)₃Ir(Phenyl)(H)C! (1), mer-(Me₃P)₃Ir(COC₆H₅)(H)Cl (II), mer-(Me₃P)₃Ir(Pyridyl)(H)Cl (IID, and mer-(Me₃P)₃Ir(furyl)Cl …
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C-H on the Oxo Ferryl Wheel: Comparison of Pyridine and Imidazole-Substituted Ligands for C-H Activation and Functionalization
<p>The selective and efficient transformation of hydrocarbon feedstocks is of high value for industry and research. While Shilov-type organometallic methods have facilitated this goal, systems designed after nature’s use of cheap and abundant iron-based enzymes are desired for wider-scale …
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The arylation of 2-pyrones and related heterocycles
… activity. Chapter 1 provides a review of C–H activation methodology as it has been applied to 2-pyrones and related heterocycles. Direct arylation via C–H activation of 2-pyrone, 2-pyridone and 2-coumarin compounds is described in Chapter 2. Protocols for the palladium-catalysed direct …
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Direct arylation of 2-pyrones, coumarins, 2-pyridinones and 2-quinolones
Direct arylation via C-H activation displays a number of advantages over traditional (Suzuki-Miyaura, Stille, etc.) coupling reactions. The 2-pyrone, coumarin, 2-pyridinone and 2-quinolone moieties are prevalent in numerous compounds which exhibit biological activity. In addition, due to the varied …
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Design of Reagents and Ligands for Direct Palladium-Catalyzed C(sp³)–H Functionalization of Aliphatic Carboxylic Acids
… Chapter 1 provides an overview of various activation modes employed for the functionalization of C(sp3)–H bonds using carboxylic acids as directing groups. Chapter 2 describes the development of a direct C(sp3)–H fluorination strategy, enabled by the rational design of an oxidizing reagent, …
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Iridium Catalysed Borylation as a Platform for Exploring the Use of Non-Covalent Interactions to Control Regio- and Enantioselectivity
Transition metal catalysed C-H activation is a highly desirable strategy for the functionalization of organic molecules. It allows for a rapid generation of structurally complex products from simple precursors in an atom- and step-economic fashion. Iridium catalysed borylation of arenes is a …
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Computational study on the selectivity of iron-containing hydroxylase
… P450 and PtlH as examples. In this work, the C-H activation in the hydroxylation reaction of a model substrate artemisinin catalyzed by three selective P450BM3 variants was studied by combined molecular dynamics (MD) simulations and quantum mechanics/molecular mechanics (QM/MM) calculations. A …
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