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 18 of 18 for “"Oxazine"”.
-
Funktionalisierung von 6H-1,2-Oxazinen durch 1,3-dipolare Cycloadditionen und Halogenierungen
6H-1,2-Oxazines were functionalised at the C-C double bond by 1,3-dipolar cycloadditions and halogenation reactions. The reactions were carried out with 6-ethoxy-3-phenyl-6H-1,2-oxazine, 6-ethoxy-3-ethoxycarbonyl-6H-1,2-oxazine and 6-ethoxy-3-trifluoromethyl-6H-1,2-oxazine. The cycloadditions of …
-
Development of Earth Abundant Metal-Catalyzed Reactions to Construct Heterocycles
… generality of the deoxygenation to convert 1,2-oxazines into pyrroles. The exposure of ortho-substituted nitroarenes to 3 mol % of (4,7-MeO-phen)Fe(OAc)2 and phenylsilane as the stoichiometricreductant afforded six-or seven-membered N-heterocycles. The scope of the reaction is broad and …
-
Total Synthesis of Lasionectrin and Synthetic Studies Towards Pestaloxazine A
… synthetic efforts towards the synthesis of pestaloxazine A (208). Natural product 208 was extracted from a marine-derived fungus belonging to the Pestalotiopis genus, and exhibited antiviral activity against EV71 (IC50 = 16.1 μM). Pestaloxazine A (208) is a racemic alkaloid dimer which contains a …
-
Lithium and indium quinoneoximic complexes and their application in scintillation counting
… product isomeric to the Diels-Alder adduct (1,4-oxazine) obtained from the copper complexes. Re-examination of the behaviour of the copper quinoneoximato complexes towards dimethylacetylene dicarboxylate has given an insight to the mechanism of the reaction and has shown that the copper complexes …
-
Transition Metal Complexes of Novel Phenanthroline Derivatives and their Antibacterial Activity
… study involves synthesis and characterisation of oxazine-based derivative of phen and its Ag(I), Cu(II) and Mn(II) complexes. The antimicrobial effects of this ligand and its metal complexes were studied using a Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria …
-
Intramolecular (4+2) -Cycloadditions of Three Heterodienes: Nitrosoalkenes, Nitroalkenes, and Z-Alpha,beta-Unsaturated Aldehydes
… (6-6)- and hexahydroindene (6-5)-oxazine cycloadducts varied. In the enol ether cases, the success of the cycloaddition depended on the olefin geometry. Only the dienophile bearing the proper geometry for secondary orbital overlap cyclized in high yield and with good …
-
The Multicomponent Synthesis of Pyrroles from Cylcopropane S Using a One Pot Pd(0) Catalyzed Dehydrocarbonylation Protocol
… by the Kerr group has shown that tetrahydro-1,2-oxazines can be efficiently synthesized using a three component coupling reaction between a hydroxylamine, aldehyde and cyclopropane diester. This affords the desired heterocycle efficiently with a wide variety of substitution. When one esters bears …
-
Studies of complexes derived from 5-acetylamino-1,2-benzoquinone 2-oxime and related ligands
… occurence of cycloaddition and the formation of oxazine. A metal-containing product, M(II)(butynedioate), and in some cases an additional organic product, l,4-benoxazin-2-one, have been isolated. Mechanistic appraisals for the 1,4-benoxazinone formation are presented and the structure of one has …
-
Flexible access to an array of enantiomerically-enriched oxabisipidines and their use as chiral ligands in asymmetric synthesis
… prepared, utilising an optically-pure common oxazine intermediate and commercially available aldehydes. In efforts towards establishing efficient access to such molecules, a fully optimised route, which is amenable to the preparation of the optically-pure oxazine on a multigram scale, has been …
-
Cyclic nitrones: oxidation studies and the synthesis of a heterocyclic nitrone
… of the heterocyclic nitrone, Δ³-dihydro-1,4-oxazine 4-oxide, by the oxidation of solutions of 4-hydroxymorpholine is described. The UV and IR spectra of the solutions were consistent with the structure proposed. Removal of the solvent gave linear polymers with the N-O-C repeating unit. …
-
The development of novel hybrid poly (2-oxazoline)-based bioinks for 3D bioprinting: a comparative study with Pluronic F127
… (POx) (A-block) and poly(2-n-propyl-2-oxazine) (POzi) (B-block) was investigated as the potential alternative for PF. In this work, two different hybrid platforms consisting of synthetic POx-b-POzi /natural polymer (chitosan or alginate) and PF /natural polymer (chitosan or alginate) …
-
Total syntheses of (±)-dracephalone A and (±)-dracocequinones A and B, progress towards a total synthesis of cassiabudanols A and B, and synthetic studies towards total synthesis of N-oxy-diketopiperazine containing natural products.
… as the key step in constructing the oxazine core. In utilizing (+)-raistrickindole A as a late-stage intermediate to target (-)-haenamindole, optimization efforts of the route, especially Mukaiyama hydration and diketopiperazine (DKP) formation steps, are discussed to achieve overall …
-
Bicyclic Heterocyclic Systems Derived from 1, 3, 4-Trisubstituted Pyridines
… 6-oxides; the reaction of the pyrido-oxazine 6-oxides with ammonia generally gives the diamides, whereas reaction with hydrazine under similar conditions gives the 3-aminopyrido [4, 3-d] pyrimidin-4(3H)-one 6-oxides. The mechanisms of these reactions are discussed. The reaction of …
-
The behavior of uranium in the environment : bacterial reduction of an aqueous uranium species
… to analyze uranium ion complexion with several oxazine dyes that included Brilliant Cresyl Blue, Celestine Blue, and Gallomine Triethoiodide. Complexion and resultant color changes with U(VI) and U(IV) with the dye solutions were tested at a variety of pH levels. The dye behavior was evaluated …
-
Progressing the Synthesis, Coordination Chemistry and Biological Evaluation of Phenanthrolines
… (iv) the synthesis of phenanthroline-oxazine (phenoxazine) ligands via an unusual cyclisation reaction with 1,10-phenanthroline-5,6-dione and specific aromatic amino acid esters; (v) the synthesis of a novel imidazo-pheanthroline-folic acid-appended ligand and its corresponding metal …
-
Application of natural dyes in textile industry and the treatment of dye solutions using electrolytic techniques
… > TBO > TH. However, the azine, acridine and oxazine dyes showed between 98 to 99% colour removal and the following decreasing order: NB ≈ NR > AO ≈ RS. Strongly electron withdrawing substituents such as nitro group or carbonyl group increases the degradation of the phenothiazine chromophore, …
-
Mechanistic Studies of Donor-Acceptor Cyclopropanes
Cyclopropane 1,1-diesters have been investigated as a source of donor-acceptor cyclopropanes, providing an understanding of the mechanism of reaction between these cyclopropanes and nitrosoarenes, as well as azo dicarboxylates. Cross-over experiments have been utilized to provide key pieces of …
-
SYNTHESIS OF N-HETEROCYCLES VIA PALLADIUM-CATALYZED REDUCTIVE CYCLIZATION REACTIONS OF NITROARENES AND NITROALKENES USING FORMIC ACID DERIVATIVES AS CO SURROGATES
The reductive cyclization reaction of nitroarenes to produce N-heterocycles has been investigated for more than four decades using CO as a cheap reductant, but it is still a fascinating area for research and advancements. On the other hand, using toxic CO gas is accompanied by many …