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Showing 1 to 18 of 18 for “"Enamines"”.
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1,1-enediamines and β-substituted enamines in heterocyclic synthesis
… deals with l,l-enediamines and ~ -substituted enamines (push-pull olefines) and their reactions, leading to the formation of a number of heterocycles. Various ~-substituted enamines were prepared by a 'one pot synthesis' in which a l,l-enediamine presumably acts as an intermediate. These …
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I. The Course of Formic Acid Reduction of Enamines. Ii. The Course of Mild Oxidation of Saturated Tertiary Amines
Made available in DSpace on 2015-05-12T17:02:34Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 0019864.PDF: 4296429 bytes, checksum: 3e0c165b8e54094ad75f45612a81f92b (MD5) Previous issue date: 1956
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Investigation of Factors Influencing Recombination Versus Disproportionation of Complex Radicals Formed by C-N Homolysis of Breslow Type Intermediates and Related Compounds
<p>Electron rich enamines are capable of C-N bond homolysis and subsequent recombination and/or disproportionation. It is unclear what causes these radicals to undergo recombination or disproportionation. Density Functional Theory (DFT) calculations do not provide a transition state for the …
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Studies in Synthesis and Organocatalysis: (i) The Design and Synthesis of Novel Electron Deficient Dienes and their Application in the First Enamine Activated Organocatalytic 1,6-Conjugate Addition. (ii) The Development of a New Organocatalytic Methodology through the Combination of DNA-Based Catalysis and Organocatalysis
… on the sulfonyl acceptors, using aldehydic enamines, giving excellent yields and selectivities (up to 98% yield, uniformly 99% ee). The mechanism of this reaction was explored in detail. The products of these additions were fully characterised and were subsequently used as substrates for the …
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DFT Studies of the Organocatalytic Aldol Reaction and a Frustrated Lewis Pair
… for the asymmetric hydrogenation of imines and enamines was designed and the ability of hydrogen splitting by this new FLP system was examined by computational modeling and calculating the hydrogen activation energy barrier.
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Construction and Application of Reference Scales for the Characterization of Cationic Electrophiles and Neutral Nucleophiles
… adding various new classes of nucleophiles like enamines, phosphanes and phosphites, and pyridines as well as by adding new electrophiles. Kinetic data for electrophile-nucleophile combinations were used for discussing structure-reactivity relationships, as well as for the analysis of mechanistic …
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New carbon-nitrogen bond-forming reactions of palladium
… upon warming to -40 °C, reacted to generate enamines. The final products, enamines, are formed by migratory insertion and subsequent β-hydride elimination. In a subsequent report, reactions of a family of these complexes containing ancillary ligands having systematically varied electronic and …
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A Diversity-Oriented Synthesis Approach to Functionalized Azaheterocycles using Cyclic Alpha-Halo Eneformamides
… through the intermediacy of α-halo enamines/enamides. The synthetic utility of the method is exemplified through the construction of quaternary cyclic propargylic and homoallylic amines, polycyclic lactams, as well as chiral dihydro 1,4-oxazines and thiazines. Given the generality of …
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Novel Conjugate Additions and Cyclizations on Multiyne Systems
… carbocyclization reactions of enol ethers and enamines under thermal and metal-catalyzed conditions to generate novel molecular scaffolds. These enol/thioenol ethers and enamines are generated in situ from 1,3-diynyl ketones via hydrogen bonding directed tandem 1,6/1,4-addition. The …
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Exploration of mild and selective hydrozirconation reactions facilitated by zirconocene hydride catalysts generated in Situ.
… catalytic conversion of esters to imines and enamines. In addition to carbonyl reduction, we have utilized ZrH catalysis to achieve the catalytic partial hydrogenation of alkynes. Ongoing work expands this catalytic protocol to novel redox-economical transformations enabled by synergistic …
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Novel synthetic methodology employing transition metal catalysed reactions of α-diazo-β-keto sulfonamides and α-cyano-α-diazoacetates; the impact of substituents on the reaction pathway
… range of products, including alkynesulfonamides, enamines, and α-halosulfonamides, with no evidence for intramolecular C–H insertion in any of the reactions, in contrast to the reactivity of the comparable α-diazo-β-oxo sulfones and α-diazosulfonates. Use of copper(II) triflate (5 mol%) led to the …
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The right of self-determination of majority-minority groups within nation-states: a case study of Bangladesh
… and organization of the study. Chapter II enamines the evolution of the right of self-determination of peoples through ancient, medieval and modern times, and shows how the inalienable right of self-determination of peoples, recognized in the customary international law, has now been …
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A novel photocatalytic strategy for complex aliphatic amine synthesis and the total synthesis of alkaloids (−) FR901483 and (+)-TAN1251C
… was expanded to include non-benzylic amines and enamines, enabling the generation of synthetically valuable $\alpha$-tertiary amines. $\alpha$-Tertiary amines are a common feature in a number of bioactive natural products. Immunosuppressant ($-$)-FR901483 (1) and muscarinic antagonist …
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New chemical and biosynthetic methodologies for the study of lanthipeptides
… Spontaneous hydrolysis of the N-terminal enamines after leader peptide removal results in α-ketoamides that site-specifically react with an aminooxy-derivatized alkyne or fluorophore. The fluorescently-modified lantibiotics were added to bacteria, and their cellular localization was …
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Part 1. the mesomorphic properties of arloxy-s-triazines and their analogs, Part 2. the synthesis and polymerization behavior of α-aminonitriles and related compounds
… route to ketones is through the reaction of enamines with appropriate electrophiles followed by acid hydrolysis. Research towards polymeric ketones was Carried out using monomeric di(enamine)s and aromatic diacid chlorides with the hope of producing high molecular weight polymeric …
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Synthesis and reactivities of titanocene-oxo complexes and rhodium-catalyzed oxidative amidation
… a highly enantioselective isomerization to enamines, then oxidative amidation to chiral amides in good yield and excellent enantioselectivity. The synthesis of α,β-disubstituted amides proved to be much more challenging, as tetrasubstituted allylamine showed no reactivity and a related …
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Part I. Rhodium-catalyzed asymmetric functionalization of allylic amines Part II. Harnessing kinetic driving forces in alkyne metathesis for the synthesis of complex molecular architectures
… isomerization of allylic amines to chiral enamines would serve as a powerful platform for the modular functionalization of a general electrophile. Nucleophilic attack onto an enamine in the presence of water leads to the formation of a hemiaminal or hemiacetal depending on the nucleophile. …