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.
Results
Showing 1 to 20 of 31 for “"carbon-carbon bond formation"”.
-
Carbon-Carbon Bond Formation Via o-Lithiointermediates
The process of C-C bond formation via Directed ort/zo-Metalation (DoM) consists of two separate steps. Utilizing 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 …
-
NEW TRANSITION METAL CATALYSTS FOR CARBON-CARBON BOND FORMATION
… complexes have been applied to the formation of carbon-carbon bonds both as reagents and catalysts. Ligands and complexes tailored for a particular reaction have facilitated superior yields, catalytic activity, and selectivity. This dissertation focuses on two catalyst systems …
-
Palladium catalyzed carbon-carbon bond formation at carbon-hydrogen bonds
… years, no general catalysts exist for this transformation, and in a lot of cases reactivity remains a challenge. This thesis will outline our work in this area of research. First, our efforts toward the development of a general catalyst for the intramolecular direct arylation of aryl halides with …
-
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 …
-
Carbon-carbon bond formation methods for the preparation of shape-persistent architectures
Carbon-rich, conjugated organic scaffolding is a popular basis for functional materials, especially for electronic and photonic applications. However, synthetic methods for generating these types of materials lack diversity and, in many cases, efficiency; the insistence of investigators focusing on …
-
(N-heterocyclic-carbene)Copper(I)-catalyzed carbon-carbon bond formation using carbon dioxide
… towards the development of a new catalytic C-C bond forming reaction. Alkynes and olefins insert into [(IPr)CuH]2 (IPr = N,N-bis-(2,6-diisopropylphenyl)-1,3-imidazol-2-ylidene) to give copper vinyl and copper alkyl complexes. These copper complexes insert CO2 into the Cu-C bond to form copper …
-
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 …
-
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 …
-
Rhodium-catalyzed Asymmetric Carbon-Carbon Bond Formation Leading to the Development of Rhodium/Palladium Multi-metal Catalysis
This thesis describes the development of rhodium-catalyzed asymmetric ring opening of strained alkenes and the subsequent use of rhodium and palladium catalysis in the development of domino reactions. The contents are divided into 4 chapters. Chapter 1 describes the rhodium-catalyzed asymmetric …
-
Application of a palladium/tri-tert-butylphosphine catalyst system towards mild and general methods for carbon-carbon bond formation
… methods for conducting palladium-catalyzed carbon-carbon bond forming reactions utilizing the bulky and electron-rich trialkylphosphine, tri-tert-butylphosphine (P(t-Bu)3). We have concentrated on the utilization of aryl chlorides as substrates due to their lower cost and greater …
-
Photoredox activation of carbon dioxide and unactivated aliphatic carbonyl compounds
Chapter 1: Photoredox Activation of Carbon Dioxide for Amino Acid Synthesis in Continuous Flow. Although carbon dioxide (CO₂ ) is highly abundant, its low reactivity has limited its use in chemical synthesis. In particular, methods for carbon-carbon bond formation generally rely on two-electron …
-
Chiral acyl radicals generated by visible light enable stereoselective access to 3,3-disubstituted oxindoles: application toward the synthesis of (–)- and (+)-physovenine
Radical species serve as powerful tools for carbon-carbon bond formation in synthetic organic chemistry. Such species can be formed in an efficient and environmentally friendly manner by way of photoredox catalysis, which uses a photocatalyst in conjunction with visible light (typically) to …
-
Development of a synthetic route to aminofluorohexenones as precursors for novel caspase inhibitors
… first involves investigation of a method for carbon-carbon bond formation adjacent to nitrogen, that focuses on an electrophilic substitution reaction based on charge affinity inversion of customary amine reactivity. The second part of the synthetic strategy involves generation of pentenoic …
-
BINOL-Catalyzed Asymmetric Synthesis of Chiral Heterocycles; Experimental Mechanistic Study of Binol-Catalyzed Conjugate Addition of Vinylboronic Acids to Enones; Enantioselective Synthesis of Diarylalkane Compounds via Binol-Catalyzed Conjugate Addition
… studies, the rate determining step of the transformation was the carbon-carbon bond formation. In another project, we carried out a Hammet plot study to investigate the electronic effects of the aryl groups on the reaction rate. The results provided solid support for the proposal mentioned …
-
Palladium-Imidazolium Carbene Catalyzed Heck Coupling Reactions and Synthesis of a Novel Class of Fluoroanthracenylmethyl PTC Catalysts
… alkenyl halides has become a powerful means of carbon-carbon bond formation. This standard synthetic method has been developed to a high level of utility using various catalysts, conditions and substrates. Yet significant drawbacks remain, including poor reactivity, the need for high …
-
Stereoselective synthesis : studies involving dipole-stabilized carbanions alpha to nitrogen
… endeavour. The ability of organolithiums to form carbon-carbon bonds in a stereoselective and predictable way is vital to their success in organic synthesis. The first chapter in this thesis summarizes the current mechanistic understanding of asymmetric carbon-carbon bond formation adjacent to …
-
Modular Methods for the Synthesis of α-Tertiary and α-Branched Alkylamines via Visible-Light-Mediated Radical Generation
… photoredox catalysis orchestrates the formation of α-tertiary amines from alkyl primary amines, alkyl ketones, and alkene acceptors. Over 50 new α-tertiary alkylamines are reported, displaying a range of structural and functional diversity in all three components. The new method enabled …
-
A study of alkylation reactions α- to nitrogen for application in alkaloid synthesis
… with a review (Chapter 1) of methodologies for carbon-carbon bond formation a to nitrogen of relevance to alkaloid synthesis, from which a specific structural motif for study in this thesis is identified. In the first phase of the research component (Chapter 2) relating to benzylic secondary aza …
-
The Kinetic Resolution of Secondary Alcohols Through A Tandem Enantioselective Silylation and the Synthesis of Bis(Oxazolidinyl)Pyridine Metal-Organic Complexes
… tandem process. The first step involves racemic carbon-carbon bond formation to generate a pair of alkoxide diastereomers. The second step involves a kinetic resolution of these diastereomers via enantioselective silylation. This reaction is the first example of a kinetic resolution of secondary …
Page 1 of 2