Download or read book The Synthesis of Isoxazol in es Via 1 3 dipolar Cycloaddition Other Heterocyclic Systems and Developments in Solid phase Organic Synthesis written by Robert E. Sammelson and published by . This book was released on 2001 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solution and Solid Phase Synthesis of Isoxazoline Containing Heterocycles written by Kristin Ann Milinkevich and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An efficient, multi-gram synthesis of a spiroisoxazolinoproline-based amino acid requiring minimal purification, delivering good cis:trans diastereoselectivity (ca. 1:4) and providing good yields is reported. Surface bound studies of the reduction of an aryl-nitro group in the presence of an isoxazoline ring with tin(II) dichloride dihydrate were undertaken to confirm the stability of the isoxazoline ring. Full derivitization of this spiroisoxazolinoproline-based amino acid scaffold was performed during the synthesis of a library. This work is described in Chapter 1. Condensation of 3-chloropentane-2,4-dione with thioamides gives 1-(thiazol-5-yl)ethanones and subsequent Wittig olefination followed by nitrile oxide 1,3-dipolar cycloaddition to the resulting prop-1-en-2-yl moiety delivers racemic 5-(thiazol-5-yl)-4,5-dihydroisoxazoles. Biological evaluation of these diheterocycles showed promising fungicidal activity. This work is described in Chapter 2. A route to 2-(4,5-dihydroisoxazol-5-yl)-1,3,4-oxadiazoles has been developed. Acid hydrazide starting materials underwent an EDC-mediated coupling with acrylic acid derivatives to form diacyl hydrazides. Cyclodehydration of the diacyl hydrazide in the presence of triphenylphospine and hexachloroethane gave 1,3,4-oxadiazoles. Lastly, in situ nitrile oxide formation and subsequent 1,3-dipolar cycloaddition to the exomethylene moiety delivered 2-(4,5-dihydroisoxazol-5-yl)-1,3,4-oxadiazoles. Biological evaluation of these diheterocycles showed weak insecticidal activity. This work is described in Chapter 3. A library of novel, propeller-shaped dispirotriheterocyclic isoxazolinopiperidinochromanones is reported. Each rigid dispirotriheterocycle was prepared in five linear steps from commercially available tert-butyl 4-oxopiperidine-1-carboxylate plus various derivatives of 1-(2-hydroxyphenyl)ethanone, benzaldehyde oxime, and carboxylic acids. Computational chemistry was employed to analyze the three-dimensional geometries of these dispirotriheterocycles as well as to generate chemoinformatic bioavailability data. X-ray crystallographic structure determination verified the regioselectivity of the nitrile oxide 1,3-dipolar cycloaddition reaction. This work is described in Chapter 4. A route to spiroisoxazolinopiperidinylbenzamides has been developed. N-Boc-4-piperidone underwent a Wittig olefination and Boc deprotection followed by an ipso substitution with 4-fluoro-3-nitrobenzoic acid to yield the starting scaffold in excellent yields. Diversification of the acid with primary amines, followed by in situ nitrile oxide formation and subsequent 1,3-dipolar cycloaddition to the exomethylene moiety delivered the spiroisoxazolinopiperdine intermediates. Reduction of the arylnitro followed by acylation or reductive amination yielded the spiroisoxazolinopiperidinylbenzamide library. This work is described in Chapter 5.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2004 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Isoxazoles written by Paolo Grünanger and published by . This book was released on 1991 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oxazoles Volume 60 Part B written by David C. Palmer and published by John Wiley & Sons. This book was released on 2004-03-18 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis, Reactions, and Spectroscopy presents a comprehensive review of the literature from 1983 to the present covering oxazoles, mesoionic oxazoles, oxazolones, oxazolines, and chiral bisoxazolines. In-depth coverage includes synthesis, reactions, spectroscopic and physical properties for each class of compounds, as well as important developments related to the use of those compounds.
Download or read book The Chemistry of Heterocyclic Compounds Isoxazoles written by Paola Grünanger and published by Wiley-Interscience. This book was released on 2009-09-17 with total page 877 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Azoles written by Aleksey Kuznetsov and published by BoD – Books on Demand. This book was released on 2021-06-30 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Azoles are a broad and promising class of five-membered heterocyclic compounds containing from one up to five nitrogen atom(s) that can also contain sulfur or oxygen atoms. Widely used as potent antifungal agents, various azole derivatives have also demonstrated many other promising biological properties. This book covers studies of several types of thiazole-based heterocyclic scaffolds, the development of 4-thiazolidinone and thiazole derivatives with heterocyclic fragments as potential candidates for new drugs against trypanosomiasis, numerous synthetic approaches for the synthesis of 1,2,3-triazoles, the application of N-azole, N,S-azole, and N,O-azole as well as their derivatives as retarders of metallic corrosion, and the integration of azoles in materials used for renewable energy processing and applications and wood treatment.
Download or read book Isoxazoles Volume 49 Part 2 written by Paola Grünanger and published by John Wiley & Sons. This book was released on 2009-09-17 with total page 905 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new volume in a highly regarded, established series provides complete coverage of the heterocyclic chemistry of isoxazoles.
Download or read book Catalyst free Organic Synthesis written by Goutam Brahmachari and published by Royal Society of Chemistry. This book was released on 2017-11-06 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explaining methods for carrying out chemical syntheses without the use of catalysts, this book shows how avoiding catalysts during synthesis can mean less use of toxic chemicals, environmentally damaging chemicals, or endangered elements, and lower costs.
Download or read book Handbook of Fluorous Chemistry written by John A. Gladysz and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by the leading experts John Gladysz, Dennis Curran, and István Horváth, this handbook is the first to summarize all the essential aspects of this emerging field of chemistry. Whether the reader is seeking an introduction to the concept of fluorous biphase catalysis, summaries of partition coefficients involving fluorous and organic solvents, or information on the latest fluorous mixture separation techniques, this authoritative compilation of contributions, written by the world's top authors, provides key information needed for successfully working with the diverse and fascinating families of fluorous molecules. The large number of reliable experimental procedures in particular makes this the ideal guide for newcomers wanting to use this elegant method in the laboratory. In addition, experts will also find a wealth of important information concisely contained in one ready reference. The result is an indispensable resource for everyone currently working or intending to work in this field.
Download or read book Solid Phase Organic Synthesis of Novel Isoxazole Polymers and CBS Catalysts written by Jose Eduardo Cobar and published by . This book was released on 2005 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2007 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrochemically Enabled Synthesis of Substituted Isoxazolines written by Samuel David Lee Holman and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthetic electroorganic chemistry has recently become an attractive method for the preparation of many organic molecules.1 With the introduction of enabling technologies, such as IKA's ElectraSyn 2.0, synthetic electrochemistry can be applied in a standardised way, allowing reproducible procedures. The study presented herein explores the electrochemical synthesis of substituted isoxazolines, using an inexpensive, environmentally benign mediator. Isoxazolines can be found in many natural products, as well as pharmaceutical and agricultural compounds. Traditionally, isoxazolines have been prepared using 1,3-dipolar cycloaddition reactions between nitrile oxides and dipolarophiles; other methods, such as transition metal-catalysed ring closures, have also been reported. However, nitrile oxides, with the exception of sterically encumbered aromatic nitrile oxides, are reactive and rapidly form dimers. In-situ preparations of these highly reactive species have been developed, though these often require toxic and/or expensive reagents, such as electrophilic halogenating agents and strong oxidants. There have been very few reports of more benign and environmentally friendly procedures, with alternative approaches which address these issues desirable. The electrochemically enabled synthesis of substituted isoxazolines has been realised, with a substrates scope of 45 examples that were isolated in up to 86% yield. Of particular note, previously elusive alkyl derived aldoximes have been successfully electrolysed under the optimised conditions, furnishing the desired products in moderate to good yields. Furthermore, green metrics were obtained that showed that this electrochemical procedure has a smaller impact on the environment when compared with other non-electrochemical methods. Building on previous work by Shono, it is envisioned that an electrochemical oxidation of a halide anion and subsequent combination with an aldoxime, followed by further oxidation and deprotonation by conjugate base, could generate a nitrile oxide. This nitrile oxide could participate in a 1,3-dipolar cycloaddition reaction with a dipolarophile to fashion a substituted isoxazoline. The reaction pathway was probed using both in-situ IR monitoring (using the commercially available ReactIR experimental set up) and 1H NMR. IR reaction profiling revealed pseudo-zero order reaction kinetics, as expected of a surface-mediated reaction. 1H NMR profiling of the electrochemical reaction between para-substituted benzaldehyde oximes and tertbutyl acrylate allowed Hammett and Swain-Lupton analyses to be performed. These analyses gave an inverted V-shaped plot that is indicative of change in rate-limiting step, consistent with a 1,3-dipolar cycloaddition reaction of ambiphilic nitrile oxide dipoles, as the change in rate-limiting step is attributed to the change in interacting frontier molecular orbitals. These NMR profiles may suggest that underlying physical phenomena may be responsible for the inverted V-shape of the Hammett and SwainLupton analyses. [See thesis for illustration] Additionally, the batch electrochemical reaction was successfully adapted into a flow procedure. These early results have allowed the isolation of the desired isoxazoline in 49% yield, showing great promise. Further work needs to be conducted as full consumption of starting material after a first-pass through the electrochemical cell has not been achieved to date.
Download or read book Review on Synthesis of Isoxazolines Pyrazolines Compounds written by Nadia Elkanzi and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: My book summarize with the different methods for synthesis of Isoxazoliens from 2-alkyn-1-one O-methyl oximes,1, 3-dipolar cycloaddition of phenyl vinylic selenide to nitrile oxides, reaction of alkenes or alkynes with ketones, Microwave irradiation of propane-l-(1,3-benzodioxol-5-yl)-3-phenyl-l,3-dione with hydroxylamine hydrochloride, Also pyrazoles synthesiszed by 3- Acetyl benzpyrid-4-imno-2-oxime hydrazine hydrate (phenyl hydrazine),2- cyanomethyl benzimidizole -2, 2- dicarboxaldehyde (94) reacts with hydrazine hydrate, condensation of acetic acid azide of hydrazine and/or phenyl hydrazine with ethyl cyanoacetate under fusion afforded the pyrazole.
Download or read book Isoxazoles Volume 49 Part 1 written by Paola Grünanger and published by Wiley-Interscience. This book was released on 1991-01-16 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new volume in a highly regarded, established series provides complete coverage of the heterocyclic chemistry of isoxazoles.
Download or read book A Tactical 1 3 dipolar Cycloaddition Approach for the Synthesis of Carbohydrate Derived Polycyclic Spiro Heterocycles written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrile Oxides Nitrones and Nitronates in Organic Synthesis written by Henry Feuer and published by John Wiley & Sons. This book was released on 2008-01-02 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive systematization of current novel data in nitrile oxide chemistry, this book authoritatively covers systematic strategies currently used in the preparation and utilization of nitrile oxides, nitrones, and nitronates in organic synthesis. It covers factors governing their stability and includes in-depth information on stable and unstable nitrile oxides. With contributions from leading experts, this is a definitive reference for practicing professionals in organic or medicinal chemistry and an excellent text for students studying organic synthesis.
