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Showing 1 to 20 of 34 for “"Carbon-carbon bond forming"”.
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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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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 …
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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 …
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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 …
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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 …
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Mechanistic Studies of Vitamin B(12)-Catalyzed Dechlorination and Carbon-Carbon Bond-Forming Reactions
… can be dimerized 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 …
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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 …
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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.
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The versatility and utilization of phosphorus based compounds in classic carbon-carbon bond forming and esterification reactions
The phosphonium salt room temperature ionic liquid tetradecyltrihexylphosphonium chloride (THPC) has been employed as an efficient reusable media for the palladium catalyzed Suzuki cross-coupling reaction of aryl halides, including aryl chlorides, under mild conditions. The cross-coupling reactions …
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Design and Development of New Catalytic Carbon-Carbon Bond Forming Reactions: I. N-Heterocyclic Carbene Based Catalytic Platform for Hauser-Kraus Annulations II. Copper-Catalyzed Selective Allylic Alkylation of Allylic Systems Using Grignard Reagents
The construction of carbon-carbon bonds has always been at the forefront of synthetic organic chemistry for generating products of greater utilities. Owing to their extraordinary applications in the synthesis of a wide range of therapeutic small molecules and natural products, the design and the …
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Part I. A Novel Vitamin B(12) Catalyzed Carbon-Carbon Bond Forming Reaction: Mechanistic Investigations and Aryl Alkene Cyclization. Part II. Mechanistic Investigation of Prostaglandin H Synthase Through the Synthesis of Site Specifically Substituted Arachidonic Acids
Finally, the syntheses of site-specifically deuterated arachidonic acids containing a remote tritium label are reported. These radiolabeled substrates would allow the characterization of the initial radical intermediate for PGHS under aerobic conditions and enzyme turnover. The substrates could …
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2-Silicon-Substituted 1,3-Dienes: Participants in Diels-Alder Chemistry and Metal-Mediated Processes
… synthetic organic chemistry are asymmetric carbon-carbon bond forming processes and catalytic one-pot reactions. Two processes that are of interest to our research are the Diels-Alder reaction and transition-metal-catalyzed cross-coupling reactions. Issues that arise in these processes …
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Brønsted acid-catalyzed reaction of alkynyltrifluoroborates with acetals and ketals
… compounds. Specifically, the formation of new carbon-carbon bonds is of great importance in synthetic organic chemistry. Brønsted acid catalysis is a powerful synthetic tool to make many different compounds, however, the current carbon-based nucleophiles are the major limitation of …
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Nickel-catalyzed cross-couplings of unactivated secondary and tertiary alkyl halides and photoinduced copper-mediated asymmetric C-N cross-couplings
… 1.1, asymmetric [gamma]-alkylation relative to a carbonyl group is achieved via the stereoconvergent cross-coupling of racemic secondary [gamma]-chloroamides with primary alkylboranes. Section 1.2 describes the first Suzuki carbon-carbon bond-forming reaction using tertiary alkyl halides as …
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PHOTOCHEMICAL AND TITANIUM (II) MEDIATED METHODS FOR THE SYNTHESIS OF COMPLEX MOLECULAR SCAFFOLDS
… The reaction involves two consecutive carbon-carbon bond forming steps. The bridged tricyclic intermediates would violate Bredt’s Rule and prevent the final carbon-carbon bond formation. This transformation can access a wealth of cyclic amino-ketones from olefin-tethered lactams. In …
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Direct Brønsted acid-catalyzed functionalization of benzhydryl alcohols and 2-ethoxytetrahydrofuran using potassium trifluoroborate salts
… group tolerance. A Brønsted acid-catalyzed carbon-carbon bond forming methodology involving alkenyl- and alkynyltrifluoroborates and in situ generated carbocations has been developed. In the presence of HBF4, we have shown that organotrifluoroborates react with benzhydryl alcohols to afford …
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SYNTHESES AND METAL MEDIATED REACTION CHEMISTRY OF 2-SILYL-1,3-DIENES
Asymmetric carbon-carbon bond forming processes and catalytic one-pot reactions remain challenges in organic synthesis. Since the discovery of the Diels-Alder reaction over eighty years ago, it has been one of the most important tools for synthetic organic chemists to synthesize as many as three …
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Nickel-catalyzed asymmetric cross-couplings of secondary allylic chlorides and planar-chiral compounds in asymmetric synthesis
In Part I, nickel-catalyzed asymmetric carbon-carbon bond-forming reactions are described. A nickel/Pybox system effectively catalyzes regio- and enantioselective cross-couplings between racemic secondary allylic chlorides and readily available alkylzinc halides. This method is applied to generate …
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Annulation strategies for the synthesis of azulenes and polycyclic nitrogen heterocycles
… application in transition metal-mediated carbon-carbon bond forming reactions. These reactions have been used to further functionalize the five- and seven-membered rings and also in the synthesis of oligoazulenes and azulenylamino acid derivatives. In addition, polycyclic nitrogen …
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Asymmetric nickel-catalyzed three-component assembly of allylic amines from alkynes, imines and organoboron reagents
… geometry of the product in the course of two carbon-carbon bond forming events. Even though nickel- catalyzed multi-component coupling reactions involving additions to carbonyl compounds have been reported, the process described herein is the first such example involving imines and also the …
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