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 95 for “"Carbon-carbon Bond"”.
-
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 …
-
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 …
-
Nucleophilic Carbon-Carbon Bond-Forming Reactions of 2-Methylenetetrahydropyrans
… C6-substituted enol ether substrates.</p> <p>The carbonyl-ene reaction of exocyclic enol ethers provides 2-β hydroxy dihydropyrans in excellent yields at room temperature. This process only requires catalytic levels of zinc chloride, and both activated and non-activated carbonyl-enophiles act as …
-
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 enabling …
-
Development and application of carbon-carbon bond forming methodologies
… An organocatalytic, asymmetric addition of carbon nucleophiles to prochiral aldimines was developed. This transformation capitalizes on the inherent properties of boron to promote a ligand exchange with chiral diols generating a chiral nucleophile in situ. Mechanistic studies were carried …
-
Palladium catalyzed carbon-carbon bond formation at carbon-hydrogen bonds
… functionalization of a sp2 or sp3 C-H bond.
-
Selective, nickel-catalyzed carbon-carbon bond-forming reactions of alkynes
… desirable. Several novel, nickel-catalyzed carbon-carbon bond-forming reactions of alkynes that display excellent regioselectivity and (E/Z)-selectivity are described. These reactions afford synthetically useful allylic and homoallylic alcohols, often with high enantioselectivity. A highly …
-
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 …
-
Lanthanide-Based Precatalysts For Carbon-Carbon Bond-Forming Reactions In Aqueous Media
<p>The formation of carbon-carbon bonds is of great interest to synthetic chemists because these bonds make up the majority of biologically active compounds. The Mukaiyama aldol reaction is a Lewis-acid-catalyzed carbon-carbon bond-forming reaction that has the ability to produce optically active …
-
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 …
-
Mechanistic Studies of Vitamin B(12)-Catalyzed Dechlorination and Carbon-Carbon Bond-Forming Reactions
… with unusual regioselectivity forming a new carbon-carbon bond between the benzylic carbons of each coupling partner. Dimerization products were obtained in good to excellent yields for mono- and 1,1-disubstituted alkenes, and dienes containing one aryl alkene underwent intramolecular …
-
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 …
-
Stereoselective carbon-carbon bond forming reactions using chiral phosphorus(V) compounds and the derived anions
… diamines were synthesized in order to examine carbon-carbon bond forming reactions using chiral auxiliary-based phosphorus reagents. The general utility of these diamines as chiral auxiliaries in the diastereoselective alkylation of P-alkyl anions was examined. A systematic study of the …
-
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 …
-
Development of new transition metal-catalyzed carbon-fluorine, carbon-nitrogen, and carbon-carbon bond forming processes
… indicated that the extent to which the Cu-P bonds of the alkylcopper intermediate distort, determines the regioselectivity of the reaction.
-
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 …
Page 1 of 5