Global ETD Search
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 13 of 13 for “"migratory insertion"”.
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The nickel-catalyzed Mizoroki-Heck reaction : high regioselectivity in Olefin migratory insertion and photoredox-enabled indoline formation
[chemical formula and color illustrations ...] Achieving high selectivity in the Heck reaction of electronically unbiased alkenes has been a longstanding challenge. Using a nickel-catalyzed cationic Heck reaction, we were able to achieve excellent selectivity for branched products (>/=19:1 in all …
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New carbon-nitrogen bond-forming reactions of palladium
… mediated C-N bond-forming reactions: the migratory insertion of an unactivated alkene into a palladium-nitrogen bond and the reductive elimination of an alkylamine from a low-valent alkylpalladium amido complex. These reactions were previously proposed as steps in palladium catalyzed …
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New Strategies and Transformations for the alpha-Functionalization of Amines to Access Chiral Amines
… deprotonation of ketimines/aldimines, then a migratory insertion process from metal-hydrides to 2-azadienes have been further developed. Of these processes, this thesis work will specifically focus on the research exploration of three synthons: 2-azaallyl anion, 2-azaaalyl radical and …
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C-H activation: oxidative addition to an iridium(I) center and reactivity of the resulting iridium(III) species
… 1,4-di-t-butyldienyl complex (VIII) by a double insertion of the alkyne with one t-butyl group forming an agostic interaction with iridium. Deuterium labeling experiments revealed the mechanism to involve: initial acetylene coordination after the chloride ligand was removed by TI⁺ followed by a …
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Zirconium-mediated alkyene-aldehyde coupling, rhodium-catalyzed alkene hydrothiolation, and copper-catalyzed alkyne hydroarylation: Reaction development and mechanistic investigations
… addition into the S–H bond, followed by migratory insertion, and finally reductive elimination. The regiodivergence in the reaction is a result of the selectivity for the migratory insertion. The anti-Markovnikov reaction undergoes a Rh–H insertion, followed by Rh–S reductive elimination, …
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Development of a Ni-Catalyzed Enantioselective Intramolecular Mizoroki- Heck Reaction for the Synthesis of Phenanthridinone Derivatives
… and a computational study of the key 1,2-migratory insertion step shed light on the catalytic cycle and the basis for the enantioselectivity. Altogether, this work presents a very attractive alternative to the palladium-catalyzed process and should facilitate the application of Ni …
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Controlling Site-Selectivity in Palladium-Catalysed Cross-Coupling Reactions using Non-Covalent Interactions Between Ligand and Substrate
… secondly, to control the regioselectivity of the migratory insertion step. However, this was met with limited success. The ligand library was then evaluated in the Suzuki-Miyaura reaction of dihaloarenes that bear a hydrogen bond donor group. Employing a sulfonated dialkylbiaryl phosphine ligand …
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The Pd-catalyzed fluorination of (hetero)aryl bromides and triflates
… revealed that it likely proceeds via a concerted migratory insertion into the bottom ring of the ligand. Chapter 2: This chapter describes extensive work to understand the mechanism by which regioisomeric mixtures of products form during the Pd-catalyzed fluorination of electron-rich aryl …
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Catalytic hydroboration: a study of model hydridoiridium and hydridorhodium boron complexes
… dissociation and acetylene coordination, migratory-insertion into the Ir-H bond to form the metallo-vinyl complex, and finally reductive elimination to produce trans-alkylvinylborole esters. The stable metallo-vinyl complex, <b>IX</b>, produced in the reaction of <b>II</b> with dimethyl …
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Fluorocarbene, Fluoroalkyl, and Fluoride Complexes of First-Row Transition Metals
… cobalt(III) fluorocarbenes, which undergo migratory insertion reactions of the fluorocarbene into the perfluoroalkyl ligand. Using a similar synthetic approach, nickel(II) and palladium(II) difluorocarbene complexes are prepared from their corresponding trifluoromethyl precursors. The …
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The catalytic hydrogenation of carbon-carbon and carbon-nitrogen multiple bonds by a cobalt(I) complex
… complexes served as a platform to study migratory insertion of alkenes, as well as, the scrambling of H2 and D2. These studies also demonstrate that the MesCCC ligand system not only supports the hydrogenation activity but has the proper spectroscopic features to elucidate key mechanistic …
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Mechanistic studies on palladium-catalyzed coupling reactions
… olefins at room temperature, and these fast insertions indicate that the anionic complexes are kinetically competent to be intermediates in Heck−Mizoroki reactions conducted under “ligandless” conditions (lacking added dative ligand). Kinetic studies showed that the anionic complexes insert …
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Investigations into cyclopropanation and ethylene polymerization via salicylaldiminato copper (II) complexes
Two distinct overall research objectives are in this Master’s thesis. Very little relates the two chapters apart from the ligands. The first chapter addresses diastereoselective homogeneous copper catalyzed cyclopropanation reactions. Cyclopropanation of styrene and ethyl diazoacetate (EDA) is a …