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.
Polymers as Aids in Organic Chemistry covers the broad classifications and application of polymers in organic chemistry. This book is organized into 15 chapters that focus on the transformation of polymers and their role in other reagents that must be easily separated from their final product. After a brief introduction to polymer chemistry, the book presents a tabulation of the various types of polymers that have been used and the methods for their characterization. It then discusses the use of polymers as supports in peptide, oligonucleotide, and oligosaccharide chemistry; in peptide sequencing; in monofunctionalized difunctional compounds preparation, as aids in asymmetric syntheses; and as trapping agents in the determination of reaction intermediates. The subsequent chapters describe the use of polymers as catalysts, with particular emphasis on transition metals immobilized in the polymer matrix and used as catalysts. The concluding chapters examine polymer-immobilized compounds, enzymes, and whole cells that have been used to carry out a large number of reaction, most of which impinge on the area of organic chemistry. Polymer scientists and researchers and organic chemists will find this book invaluable.
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.
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.
This dissertation, "Development of a Multipolymer Reaction and Polyfunctional Polymeric Catalysts" by 鍾韻盈, Wan-ying, Cecilia, Chung, 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 A MULTIPOLYMER REACTION AND POLYFUNCTIONAL POLYMERIC CATALYSTS Submitted by Chung Wan Ying Cecilia for the Degree of Doctor of Philosophy at The University of Hong Kong in March 2008 Polymer-supported reagents and catalysts have long been used in organic synthesis because they simplify product purification and can often be recycled. Simultaneously using two or more such polymeric reagents and catalysts are known as multipolymer reactions. A complementary extension of this concept is to use a single polymer that contains two or more different reagent and/or catalyst groups. We have developed several such polyfunctional polymeric reagents and catalysts. The scientific literature regarding multipolymer reactions and polyfunctional polymers in the context of organic synthesis was reviewed. The synthesis and application of both a monofunctional triflimide polymer and an analogous bifunctional triflimide/amine polymer were described. The monofunctional polymeric triflimide reagent was used together with an amine base to transform a series of phenols into the corresponding aryl triflates. However, the bifunctional triflimide/amine polymer was not effective in such aryl triflate synthesis. A multipolymer reaction system was presented for the selective and catalytic aerobic oxidation of primary benzylic alcohols to aldehydes. Polymer-supported 2,2'-bipyridine and 2,2,6,6-tetramethyl-piperidine-1-oxyl radical (TEMPO) were synthesized and used simultaneously as ligands for copper(II) to generate the catalytically active species required for the oxidation reactions. The recyclablility of these polymers was also examined. The synthesis of two polyfunctional polymers, one soluble and the other insoluble, were reported. Both 2,2'-bipyridine and TEMPO were attached to the same polymer backbone and these were successfully utilized in the same aerobic oxidation reactions previously performed in the multipolymer reaction system. DOI: 10.5353/th_b3970744 Subjects: Organic compounds - Synthesis Chemical reactions Polymers Catalysts
This dissertation, "Amine Functionalized Polymeric Catalysts and Reagents" by Jinni, Lu, 陆今妮, 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: Polymer-supported reagents and catalysts, which allow for simple product separation and easy recycling, have been widely studied in the context of organic synthesis. The past decade has witnessed a number of new variations of polymeric materials, and among the most frequently immobilized functionalities are amines that possess versatile synthetic utilities. Polymers with new structures and improved properties for use in synthesis have been continuously developed since the support may impact the chemical reactions in which they are used in various ways. A new heterogeneous polystyrene-based amine, rasta resin-DMAP, has been synthesized and used in addition reactions of carbon dioxide to epoxides to afford cyclic carbonate products. This new material was found to be a more efficient catalyst than divinylbenzene cross-linked polystyrene supported DMAP, and was readily recycled without significant loss of catalytic activity. Compared to polymers bearing a single functionality, polymers possessing multiple different functional groups attached to a single polymer backbone would have greater potential utility, especially in reactions requiring multiple catalysts or reagents. As an example of this concept, a bifunctional polystyrene bearing both DMAP and piperazine groups has been prepared and applied as an organocatalyst for decarboxylative Doebner-Knoevenagel reactions of arylaldehydes and mono-ethyl malonate to produce (E)-,-unsaturated esters in high yields. Additionally, both non-cross-linked and cross-linked bifunctional polystyrenes featuring amine and thiourea groups have been developed, and their catalytic performance were evaluated in reactions of nitroalkenes with either nitroalkanes or sulfur ylides. Both polymers proved to be efficient catalysts in these reactions and the insoluble polymer demonstrated high recyclability. Control experiments using monofunctional polymers indicated that both catalytic groups of these bifunctional polymers are essential and they could work cooperatively to achieve efficient catalysis. Finally, a second generation bifunctional phosphine-amine polymer, rasta resin-PPh3-NBniPr2, was prepared and examined in tandem Wittig-reductive aldol reactions. In these reaction cascades, the phosphine oxide groups generated from the Wittig reaction served as the catalyst for the reductive aldol reaction, and moderate yields of structurally diverse -hydroxy ketones could be obtained from one-pot processes involving 5 sequential reactions. DOI: 10.5353/th_b4775252 Subjects: Amines Polymers Catalysts Supported reagents
The need to improve both the efficiency and environmental acceptability of industrial processes is driving the development of heterogeneous catalysts across the chemical industry, including commodity, specialty and fine chemicals and in pharmaceuticals and agrochemicals. Drawing on international research, Supported Catalysts and their Applications discusses aspects of the design, synthesis and application of solid supported reagents and catalysts, including supported reagents for multi-step organic synthesis; selectivity in oxidation catalysis; mesoporous molecular sieve catalysts; and the use of Zeolite Beta in organic reactions. In addition, the two discrete areas of heterogeneous catalysis (inorganic oxide materials and polymer-based catalysts) that were developing in parallel are now shown to be converging, which will be of great benefit to the whole field. Providing a snapshot of the state-of-the-art in this fast-moving field, this book will be welcomed by industrialists and researchers, particularly in the agrochemicals and pharmaceuticals industries.
