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Showing 1 to 20 of 21 for “"Piperidines"”.
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Stereoselective synthesis of piperidines
… a small stereodiverse library of 2-substituted piperidines. Novel chiral titanium alkylidene reagents ii alkylidenated resin-bound esters i to give acid-labile resin-bound enol ethers iii. These were cleaved to give amino ketones iv. The switch in the nature of the resin from acid-stable to …
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Highly functionalized piperidines via ring-closing metathesis of dehydroamino acids
Contains fulltext : 126486.pdf (Publisher’s version ) (Open Access)
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[4+2] cycloadditions of iminoacetonitriles : a general strategy for the synthesis of quinolizidines, indolizidines, and piperidines
… leading to quinolizidines, indolizidines, and piperidines. The resultant a-amino nitrile cycloadducts are versatile synthetic intermediates which can be further elaborated by stereoselective alkylation, reduction, reductive cyclization, and Bruylants reactions. The first part of this thesis …
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Amine Nucleophilic Addition to Nitro-alkene as a New Reaction Mode for the Synthesis of N-heterocycles
… antibiotics.;Enantioselective Synthesis of Piperidines by Exocyclic Chirality Transfer: Piperidines are very important structural moieties contained in a wide range of biologically active and medicinally significant compounds. An efficient route to chiral piperidines was developed which …
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Synthesis of Analogues Based on the Opioid Alkaloid Mitragynine
… compounds were designed and synthesized: phenylpiperidines, including phenylaminopiperidines and phenylamidopiperidines, and tetrahydro-beta-carbolines. They were further submitted to in vitro evaluation on mu, delta and kappa-opioid receptors for their binding affinities. Out of six piperidines …
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Enantioselective (Formal) Aza-Diels-Alder Reactions with Danishefsky's Diene and Non-Danishefsky Type Dienes
Highly functionalized piperidines represent an important class of heterocycles that are found in natural products and medicinally active agents. As a direct result, efforts to develop enantioselective diene-imine (aza-Diels-Alder) reactions to efficiently access these substructures have increased. …
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THREE STUDIES OF 2-PYRIDONE PHOTOADDUCT REACTIVITY
… reaction to yield unsymmtrically coupled piperidines vii. Pyridones can also undergo photo-[4+4] reactions with furans. Cycloaddition of viii yields ix. Transannular closure of ix produces triquinane x, a model system for total synthesis of crinipellin A xi.
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ORGANOCATALYTIC HALOFUNCTIONALIZATION OF OLEFINS
… resulting enantioenriched 2-substituted 3-bromopiperidines can readily be transformed to 3-substituted piperidines through a silver salt-mediated rearrangement. This process has been applied to the synthesis of a dopaminergic drug, Preclamol. Next, an asymmetric synthesis of heterospirocycles …
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A Diversity-Oriented Synthesis Approach to Functionalized Azaheterocycles using Cyclic Alpha-Halo Eneformamides
Functionalized piperidines, azepanes, azamacrocycles, morpholines, and thiomorpholines are common structural motifs found in a wide range of pharmaceuticals such as carmegliptine, levofloxacin, thioridazine, claviciptic acid, and azithomycin. As a result, there is a strong desire to construct …
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Direct ⍺-C–H Functionalisation of Cyclic Alkylamines
… for the direct ⍺-functionalisation of N-alkyl piperidines through the design of a sequential process involving iminium ion formation followed by the 1,2-addition of carbon-based nucleophiles. Key to this strategy was the selective formation of endo-iminium ions from six-membered N-heterocycles, …
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Lewis base catalyzed enantioselective sulfenoamination of alkenes
… afford nitrogen-containing heterocycles, such as piperidines, azepanes, and tetrahydroquinolines. In the course of developing an enantioselective carbosulfenylation of alkenes, a seemingly contradicting phenomenon of a catalyst inhibiting a stoichiometric reaction was observed. In the absence of …
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Modular Approaches for the Synthesis of α-Azinyl Amines and Related Scaffolds
… and pharmaceutically-relevant α-azinyl piperidines. Proposed future work is also presented, including the realisation of a comprehensive platform for the assembly of heterocyclic scaffolds which contain the α-alkyl 2-azinyl amine motif, namely 7-aminopyrindans and …
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Aliphatic Nitroxyl Radicals as Antifatigue Agents for Rubbers
… agents by a chain repair mechanism. The hindered piperidines and hydroxylamines did not greatly affect the curing characteristics of the vulcanisation process. However their nitroxyl radicals were found to retard cure. The nitrones did not particularly affect the curing characteristics either, …
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The role of stable nitroxyl radical precursors as antioxidants in polyolefins
Various 2,2,6,6-tetramethyl piperidines and their N-alkyl derivatives of stable nitroxyl radical precursors containing acrylic(s) and methacrylic(s) groups were reactively processed in the presence of a peroxide as bound-antioxidant masterbatches for polyolefin stabilisation. It was found that …
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Synthesis, pharmacological and solubility evaluation of antiplasmodial pyrido[1,2-a]benzimidazoles with cyclic and functionalized amine side chain substituents
… and also showed lower solubility compared to the piperidines. Azetidine and cyclohexylamine substitution led to compounds with moderate to poor in vitro activity and solubility. Substitution with highly polar functions and reduced basicity of the second amino group on the cyclic amine moiety were …
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HYPERVALENT IODINE METHODS FOR CARBON–NITROGEN AND CARBON–CARBON BOND FORMATION
… could serve as platform for accessing diverse piperidines, pyridones and primary amines through straightforward procedures. The combined chapters of this dissertation highlight the applications of λ3-iodanes towards transition metals and emphasize the applications of these reagents to enable …
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Asymmetric Synthesis of Nitrogen Containing Bioactive Compounds via the Utilization of Enantiopure p-Toluenesulfinimines
… active molecules, such as pyrrolidines, piperidines and other alkaloids. To further illustrate the utility of sulfinimine -derived enantiopure N-sulfinyl anti- α-lkyl β-amino ketones, they was applied to the asymmetric synthesis of the unknown anti-C5, C6 derivative of …
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Studies on Syntheses of 1-Azaspirocycles, 2,6-Disubstituted 3-Piperidinols and cls-Decahydroquinolines
Pyrrolidines and piperidines bearing a nitrogen-substituted quaternary stereocenter are commonly encountered structural motifs in many naturally occurring alkaloids, and therefore development of methods for their synthesis are important. The Rh(II)-catalyzed intramolecular tertiary C-H insertion …
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