Download or read book Studies on Polymer supported Reagents written by J. O. E. Otaigbe and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Polymer supported Reducing Reagents and the Study of Their Catalytic Properties written by Hsueh-Chi Lee and published by . This book was released on 1979 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Soluble Polymer supported Organocatalysts written by Yun-Chin Yang and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer-supported reagents and catalysts have been extensively studied in the past few decades as they not only facilitate separation and isolation of products after reactions but also enable reuse of reagents/catalysts. In particular, chemistry using polymer-supported organocatalysts has the advantage of avoiding the use of sometimes toxic transition metals. Since organocatalysts are often used at high mol% loading in catalytic reactions, immobilizing organocatalysts on polymers for recycling and reusing makes chemistry using organocatalysts attractive in larger scale syntheses. Chapter II of this dissertation focuses on using variable temperature 31P NMR spectroscopy to study and compare the dynamic behavior of silver complexes prepared from soluble polymer-supported phosphines and electronically similar low molecular weight phosphine ligands. The phosphine-silver complexes supported on terminally functionalized polyisobutylene (PIB) and poly(ethylene glycol) show similar kinetic behavior compared to their low molecular weight counterparts. However, the dynamic behavior of phosphine-silver complexes supported as pendent groups on a linear polystyrene is difficult to study because of significant line-broadening on 31P NMR spectra. Chapter III of this dissertation aims at examining the recyclability and reusability of PIB-supported phosphines as organocatalysts and reagents. PIB-supported alkyldiphenyl- and aryldiphenylphosphines were prepared and used as recyclable organocatalysts in addition and allylic amination reactions. The PIB-bound phosphines were useful reagents in aza-Wittig and Mitsunobu reactions. The PIB-bound phosphine oxides formed either from adventitious oxidation or during the course of reactions can be reduce to PIB-phosphines for reuse. Chapter IV of this dissertation describes preliminary studies on soluble polymer-supported N-heterocyclic carbene (NHC) organocatalysts. PIB- and polyethylene oligomer (PE_Olig)-supported NHC adducts were synthesized and the corresponding polymer-supported NHC catalysts were generated in situ in lactide polymerization and phenyl isocyanate trimerization reactions. The PIB-bound NHC catalyst generated in situ was not recyclable in a lactide polymerization. However, PIB- and PEOlig-bound NHC precatalysts showed modest recyclability in lactide polymerization and phenyl isocyanate trimerizations.
Download or read book Development of New Polymer Supported Reagents written by Kwok-Wai Matthew Choi and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Development of New Polymer Supported Reagents" by Kwok-wai, Matthew, Choi, 蔡國偉, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled DEVELOPMENT OF NEW POLYMER SUPPORTED REAGENTS Submitted by Choi Kwok Wai Matthew for the degree of Master of Philosophy at The Universiry of Hong Kong in December 2003 The use of polymer-supported reagents has emerged as a powerful technique in organic synthesis in what is known as polymer-assisted organic synthesis. The inherent advantages of attaching reagents to insoluble supports lie in the ease of product purification, since the supports can be filtered and also because a given reaction can be driven to completion through the convenient use of excess of such reagents. Soluble polymers are alternative supports to insoluble resins for reagent delivery and this are becoming widely used. These reagents may be used to either selectively remove impurities from synthetic products or to deliver reagents to dissolved synthesis substrates A series of new polymer-supported reagents based on both non-cross- TM linked and cross-linked (JandaJel ) polystyrene were prepared and the utility of these polymers was demonstracted by their use in organic synthesis. In this thesis, the development of two new soluble polystyrene-based sulfoxide reagents for Swern oxidation reactions are introduced. i Secondly, a simplified synthesis of 4-styryldiphenylphosphine is described and used this monomer to prepare non-cross-linked polymer-supported triphenylphosphine using a homogeneous polymerization process. It is noteworthy that the 4-styryldiphenylphosphine monomer can be incorporated into the polymers at predictable levels, depending upon the ratio of monomers used in the polymerization reaction. The utility of this polymer was demonstrated by its use in Mitsunobu reactions. Thirdly, a straightforward synthesis of trityl alcohols in which one of the aryl rings is substituted with a vinyl group was presented. These compounds were used to incorporate trityl linker groups in polystyrene-based reagent supports. TM Both non-cross-linked and cross-linked (JandaJel ) polystyrene can be prepared with these monomers and these polymers are suitable as supports for solid-phase organic and peptide synthesis. Finally, a new cross-linked polystyrene-supported thioanisole reagent was reported. This reagent incorporates the flexible JandaJel cross-linker and can be treated with methyl trifluoromethanesulfonate to form the corresponding sulfonium salt. This salt in turn can be deprotonated to form a polymer-supported sulfur ylide that is able to react with carbonyl compounds to form epoxides. The thioanisole reagent can also be oxidized to form an insoluble sulfoxide reagent that is useful in Swern oxidation reactions. These reagents derived from the polymer-supported thioanisole can be recovered, regenerated, and reused. DOI: 10.5353/th_b2923052 Subjects: Polymers Supported reagents
Download or read book Preparative Chemistry Using Supported Reagents written by Pierre Laszlo and published by . This book was released on 1987 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Preparative Chemistry Using Supported Reagents ...
Download or read book Polymer Supported Chemical Reactions written by P. Hodge and published by iSmithers Rapra Publishing. This book was released on 1991 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer supported chemical reactions may include those using supported substrates, reagents and catalysts, and this report describes all three types. In all cases the most frequent reason for the use of a polymeric support will be the ease of separation of the supported and the low molecular c099 species. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database provides useful references for further reading.
Download or read book Molecular Recognition Mechanisms Displayed by Polymer supported Reagents written by Rosario Munoz-Martinez and published by . This book was released on 1990 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies on Pentaphenylethyl Cation and Development of Polymer Supported Synthetic Reagents written by Mesfin Alemayehu and published by . This book was released on 1992 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymeric Reagents and Catalysts written by Warren T. Ford and published by . This book was released on 1986 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examines recent advances in the use of polymeric reagents and catalysts with a special emphasis on new compounds, synthetic methods, and industrial processes. Brings these advances to the attention of those who are involved in organic synthesis and desire a more thorough understanding of polymers and polymeric reagents. Contains comprehensive chapters devoted to polymeric oxidizing agents, Wittig reagents, and synthesis of cross-linked polymeric templates for chiral recognition. Presents opportunities for invention and use of many new polymeric reagents and catalysts.
Download or read book Preparative Chemistry Using Supported Reagents written by Pierre Laszlo and published by Elsevier. This book was released on 2012-12-02 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: Preparative Chemistry Using Supported Reagents explains a certain dimension in the methodology of organic reactions. This book discusses the physical methods for study that characterizes surfaces and their adsorbates and chemical reactivity at interfaces. The polymer-supported reagents, shape-selectivity within zeolites, and graphite intercalates are also described. Other topics include the metal oxides and their physico-chemical properties in catalysis and synthesis; photochemistry of adsorbed molecules; and magnetic spin resonance methods and applications to oxide surfaces. The physico-chemical characterization of supported reagents; polymer-supported oxidations; and alumina and alumina-supported reagents are likewise deliberated. This text also covers the novel aluminophosphate-based molecular sieves, clay-activated isomerization reactions, anionic activation, and cationic reactions. This publication is beneficial to chemists and researchers conducting work on supported reagents.
Download or read book Polymer Supported Reagents and Catalysts written by and published by . This book was released on 2005 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies Towards the Polymer Supported Synthesis of Dihydroaeruginoic Acid and Analogues written by Rachel Elizabeth Hosking and published by . This book was released on 1996 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of New Polymer Supported Reagents written by Kwok-wai Choi (Matthew) and published by . This book was released on 2003 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Current Topics in Polymer Research written by Robert K. Bregg and published by Nova Publishers. This book was released on 2005 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers are substances containing a large number of structural units joined by the same type of linkage. These substances often form into a chain-like structure. Starch, cellulose, and rubber all possess polymeric properties. Today, the polymer industry has grown to be larger than the aluminium, copper and steel industries combined. Polymers already have a range of applications that far exceeds that of any other class of material available to man. Current applications extend from adhesives, coatings, foams, and packaging materials to textile and industrial fibres, elastomers, and structural plastics. Polymers are also used for most composites, electronic devices, biomedical devices, optical devices, and precursors for many newly developed high-tech ceramics. This book presents leading-edge research in this rapidly-changing and evolving field.
Download or read book Design Synthesis and Applications of Polymer supported Methyl Azodicarboxylate and Other Resin bound Reagents for Use in Novel Mitsunobu Studies written by Carla Ann Maria Arena and published by . This book was released on 2001 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solid Phase Organic Synthesis written by Patrick H. Toy and published by John Wiley & Sons. This book was released on 2012-01-10 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents both the fundamental concepts and the most recent applications in solid-phase organic synthesis With its emphasis on basic concepts, Solid-Phase Organic Synthesis guides readers through all the steps needed to design and perform successful solid-phase organic syntheses. The authors focus on the fundamentals of heterogeneous supports in the synthesis of organic molecules, explaining the use of a solid material to facilitate organic synthesis. This comprehensive text not only presents the fundamentals, but also reviews the most recent research findings and applications, offering readers everything needed to conduct their own state-of-the-art science experiments. Featuring chapters written by leading researchers in the field, Solid-Phase Organic Synthesis is divided into two parts: Part One, Concepts and Strategies, discusses the linker groups used to attach the synthesis substrate to the solid support, colorimetric tests to identify the presence of functional groups, combinatorial synthesis, and diversity-oriented synthesis. Readers will discover how solid-phase synthesis is currently used to facilitate the discovery of new molecular functionality. The final chapter discusses how using a support can change or increase reaction selectivity. Part Two, Applications, presents examples of the solid-phase synthesis of various classes of organic molecules. Chapters explore general asymmetric synthesis on a support, strategies for heterocyclic synthesis, and synthesis of radioactive organic molecules, dyes, dendrimers, and oligosaccharides. Each chapter ends with a set of conclusions that underscore the key concepts and methods. References in each chapter enable readers to investigate any topic in greater depth. With its presentation of basic concepts as well as recent findings and applications, Solid-Phase Organic Synthesis is the ideal starting point for students and researchers in organic, medicinal, and combinatorial chemistry who want to take full advantage of current solid-phase synthesis techniques.
Download or read book Polymeric Chiral Catalyst Design and Chiral Polymer Synthesis written by Shinichi Itsuno and published by John Wiley & Sons. This book was released on 2011-06-28 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews chiral polymer synthesis and its application to asymmetric catalysis. It features the design and use of polymer-immobilized catalysts and methods for their design and synthesis. Chapters cover peptide-catalyzed and enantioselective synthesis, optically-active polymers, and continuous flow processes. It collects recent advances in an important field of polymer and organic chemistry, with leading researchers explaining applications in academic and industry R & D.
