Download or read book Catalytic Asymmetric Ring opening Reactions of Epoxides Mechanistic Investigation and Theoretical Studies written by Lars Peter Christian Nielsen and published by . This book was released on 2006 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of nonenzymatic, catalytic methods in the context of asymmetric ring-opening reactions of epoxides is presented. Nucleophilic-addition reactions are discussed according to the identity of the reactive nucleophilic center and are followed by a section on enantioselective rearrangements of both meso and chiral epoxides. The criteria for practicality is outlined in each case as are limitations, applications to synthesis, and mechanistic details of interest.
Download or read book Mechanistic and Synthetic Studies of Asymmetric Catalytic Epoxide Ring opening Reactions written by Karl B. Hansen and published by . This book was released on 1998 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Trends in Asymmetric Catalysis written by Giorgio Della Sala and published by MDPI. This book was released on 2021-08-30 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis of enantiopure organic compounds is a key issue for several applications in pharmacology, food chemistry, agricultural chemistry, perfumery, materials science and other industrial sectors. Nowadays, asymmetric catalysis is undoubtedly the most important tool to achieve this goal. This technology, in fact, enables the production of large amounts of enantiomerically enriched compounds, employing relatively small quantities of chiral enantiopure catalysts, which is exactly what is accomplished by enzymes in nature. Since the pioneering works of Noyori, Knowles and Sharpless, which later earned them the Nobel Prize in Chemistry, asymmetric catalysis has experienced a rapid and relentless development in the last fifty years. The tremendous expansion of enantioselective transformations, the design of novel and more efficient organometallic and organic catalysts, the development of sophisticated bioreactors and cell factories, are just some of the elements responsible for such growth. However, new challenges of asymmetric catalysis are devoted to enhancing the process’s sustainability, by the introduction of recyclable and low-cost catalysts, and the use of renewable starting materials and energy source. This book provides an overview of some of these development directions and comprises a collection of review papers and a research article authored by renowned researchers actively involved in this field. The topics covered by the review papers are photoredox-catalyzed reactions of imines, asymmetric catalytic electrosynthesis, cooperative catalysis of chiral N-heterocyclic carbenes and Lewis acid, and asymmetric ring-opening reactions of epoxides catalyzed by metal–salen complexes. The research article presents a proline-catalyzed aldol reaction in water–methanol solvent mixture.
Download or read book Development and Mechanistic Studies of a Highly Active and Selective Oligomeric Salen Co III Catalyst for Asymmetric Epoxide Ring opening Reactions written by David Emery White and published by . This book was released on 2005 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Epoxides written by Rick Reeves and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book opens with a discussion on the syntheses of acyclic polyketides by using epoxide opening reactions. The stereoselective epoxidations of allylic alcohols, including catalytic asymmetric epoxidation reactions and stereospecific reactions due to substrate-control, are described shortly. Afterwards, different epoxide opening reactions and applications in natural product synthesis are reviewed. The authors highlight the recent advances in catalytic one-pot synthesis of epoxides. The versatility of organometallic catalysts in epoxidation of alkenes are considered an important point of research in the context of these transformations. Later, occurrence of carotenoid 5,6-epoxides, their chemical synthesis, the separation of stereoisomers, some transformations of 5,6-epoxy-carotenoids, and their biological processes are described. Following this, the methodologies for the deoxygenation of epoxides using oxo-molybdenum and oxo-rhenium complexes as efficient catalysts are described, allowing a large community of readers, in particularly the community that works in catalysis, organic and organometallic chemistry, ready access to the novel methodologies developed.
Download or read book Aziridines and Epoxides in Organic Synthesis written by Andrei K. Yudin and published by John Wiley & Sons. This book was released on 2006-02-20 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aziridines and epoxides are among the most widely used intermediates in organic synthesis, acting as precursors to complex molecules due to the strains incorporated in their skeletons. Besides their importance as reactive intermediates, many biologically active compounds also contain these three-membered rings. Filling a gap in the literature, this clearly structured book presents the much needed information in a compact and concise way. The renowned editor has succeeded in gathering together excellent authors to cover synthesis, applications, and the biological aspects in equal depth. Divided roughly equally between aziridines and epoxides, the twelve chapters discuss: * Synthesis of aziridines * Nucleophilic ring-opening of aziridines and epoxides * Organic synthesis with aziridine building blocks * Vinyl aziridines in organic synthesis * Diastereoselective aziridination reagents * Synthetic aspects of aziridinomitocene chemistry * Biosynthesis of biologically important aziridines * Organic catalysis of epoxide and aziridine ring formation * Metal-mediated synthesis of epoxides * Asymmetric epoxide ring opening chemistry * Epoxides in complex molecule synthesis * Biological activity of epoxide-containing molecules A high-quality reference manual for academic and industrial chemists alike.
Download or read book Multivalency written by Jurriaan Huskens and published by John Wiley & Sons. This book was released on 2018-02-05 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Connects fundamental knowledge of multivalent interactions with current practice and state-of-the-art applications Multivalency is a widespread phenomenon, with applications spanning supramolecular chemistry, materials chemistry, pharmaceutical chemistry and biochemistry. This advanced textbook provides students and junior scientists with an excellent introduction to the fundamentals of multivalent interactions, whilst expanding the knowledge of experienced researchers in the field. Multivalency: Concepts, Research & Applications is divided into three parts. Part one provides background knowledge on various aspects of multivalency and cooperativity and presents practical methods for their study. Fundamental aspects such as thermodynamics, kinetics and the principle of effective molarity are described, and characterisation methods, experimental methodologies and data treatment methods are also discussed. Parts two and three provide an overview of current systems in which multivalency plays an important role in chemistry and biology, with a focus on the design rules, underlying chemistry and the fundamental principles of multivalency. The systems covered range from chemical/materials-based ones such as dendrimers and sensors, to biological systems including cell recognition and protein binding. Examples and case studies from biochemistry/bioorganic chemistry as well as synthetic systems feature throughout the book. Introduces students and young scientists to the field of multivalent interactions and assists experienced researchers utilising the methodologies in their work Features examples and case studies from biochemistry/bioorganic chemistry, as well as synthetic systems throughout the book Edited by leading experts in the field with contributions from established scientists Multivalency: Concepts, Research & Applications is recommended for graduate students and junior scientists in supramolecular chemistry and related fields, looking for an introduction to multivalent interactions. It is also highly useful to experienced academics and scientists in industry working on research relating to multivalent and cooperative systems in supramolecular chemistry, organic chemistry, pharmaceutical chemistry, chemical biology, biochemistry, materials science and nanotechnology.
Download or read book Catalytic Asymmetric Conjugate Reactions written by Armando Cordova and published by John Wiley & Sons. This book was released on 2010-12-01 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique and long-awaited handbook on this important topic in the hot field of stereoselective organic synthesis covers several types of nucleophiles. Top international authors deal with modern forms of achieving stereoselective conjugate additions based on the use of chiral auxiliaries or asymmetric catalysis, such as P-N ligands, organocatalysis, domino reactions, Lewis acid and base catalysis. There is also a discussion of the employment of enantioselective conjugate addition transformations in total synthesis of important molecules. With its reliable and previously unpublished experimental procedures, this is a true source of high quality information.
Download or read book Catalytic Asymmetric Chlorofunctionalization Reactions written by Aritra Sarkar and published by . This book was released on 2020 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the mechanistic exploration of various catalytic asymmetric alkene halofunctionalization reactions. The mechanistic studies were focused on asymmetric halofunctionalization reactions that are catalyzed by the well-known, commercially available catalyst (DHQD)2PHAL. Chemical kinetics were a central part of this investigation as the study entailed exploration of various kinetic properties, such as rate law equations, effects of isotopic substitution, and competition studies, to obtain key mechanistic insights into these reactions. The kinetic studies were complemented with computational modeling that led to the proposal of detailed catalytic models. Chapter 1 introduces the inherent mechanistic challenges in a successful catalytic asymmetric alkene halofunctionalization reaction and also serves as an introduction to the kinetic tools that will be utilized in the following chapters to investigate the mechanism of the reactions. Chapter 2 presents the mechanistic investigation of (DHQD)2PHAL catalyzed asymmetric chlorolactonization of alkene carboxylic acids and illustrates the mechanistic model of catalysis for this reaction. Chapter 3 presents the mechanistic investigation of DHQD)2PHAL catalyzed asymmetric chloroetherification of alkene amides reaction. Interestingly, despite being driven by the same catalyst and chlorine source, evidences pointed to the two reactions having dramatically divergent mechanistic pictures.
Download or read book Metal Organic Frameworks as Heterogeneous Catalysts written by Francesc X. Llabrés i Xamena and published by Royal Society of Chemistry. This book was released on 2013-07-01 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines the latest research and discovery in the use of MOFs in catalysis, highlighting the extent to which these materials have been embraced by the community.
Download or read book Alkaline Earth Metal Compounds written by Sjoerd Harder and published by Springer. This book was released on 2013-07-20 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Organometallic Chemistry presents critical overviews of research results in organometallic chemistry. As our understanding of organometallic structure, properties and mechanisms increases, new ways are opened for the design of organometallic compounds and reactions tailored to the needs of such diverse areas as organic synthesis, medical research, biology and materials science. Thus the scope of coverage includes a broad range of topics in pure and applied organometallic chemistry, where new breakthroughs are being achieved that are of significance to a larger scientific audience. The individual volumes of Topics in Organometallic Chemistry are thematic. Review articles are generally invited by the volume editors.
Download or read book Fundamentals and Prospects of Catalysis written by Goutam Kumar Patra and published by Bentham Science Publishers. This book was released on 2020-09-21 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalysis is an area of chemical sciences which has fascinated a wide range of academicians, researchers, chemical technologists and industries throughout the world. Progress in this field has been made owing to the thrust provided by this research and commercial interest. The field of catalysis is interdisciplinary by its nature, as it requires knowledge of organic synthesis, coordination and organometallic chemistry, reaction kinetics and mechanisms, stereochemical concepts and materials science. Fundamentals and Prospects of Catalysis highlights many important topics and sub-disciplines in catalysis by presenting 7 chapters on different but varied catalytic processes. This volume presents the following topics:· Organocatalytic Asymmetric Synthesis of Spiroacetals and Bridged Acetals· Design and Development of Bimetallic Enantioselective Salen Co Catalysts for The Hydrolytic Kinetic Resolution of Terminal Epoxides· Recent Trend in Asymmetric Heterogeneous Flow Catalysis· Ball Milling: A Green Tool in Synthetic Organic Chemistry· Recent Advances in the Developments of Enantioselective Electrophilic Fluorination Reactions via Organocatalysis· Green and Sustainable Biocatalytic Routes to Prepare Biobased Polyols as Precursors for Polyurethanes with Comparison of Existing Biobased Polyol Technology· Polymers Used as Catalysts
Download or read book Comprehensive Asymmetric Catalysis written by Eric N. Jacobsen and published by Springer Science & Business Media. This book was released on 2003-09-22 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first supplement to the three volume reference work "Comprehensive Asymmetric Catalysis" critically reviews new developments to the hottest topics in the field written by recognised experts. Eleven chapters which are already in the major reference work have been supplemented and additionally five new chapters have been included. Thus the state-of-the art in this area is now re-established. Together with the basic three volume book set this supplement is not only the principal reference source for synthetic organic chemists, but also for all scientific researchers who use chiral compounds in their work (for example, in biochemical investigations and molecular medicine) as well as for pharmaceutical chemists and other industrial researchers who prepare chiral compounds.
Download or read book The Discovery and Synthetic Applications of Catalytic Asymmetric Ring Opening Reactions written by Michael Han-cheng Wu and published by . This book was released on 1999 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Reactions of Complex Epoxides on Silver 110 written by Adrienne Claire Lukaski and published by ProQuest. This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct oxidation processes, such as ethylene epoxidation to ethylene oxide, have been researched extensively due to the uniqueness of this process and to the commercial significance of the epoxide product. Despite the importance of epoxide production, the mechanistic details of olefin epoxidation remained obscure until recently and the majority of significant advances in Ag catalyst development occurred primarily through empirical methods. Recent surface science studies of ethylene oxide on Ag(111) have identified an oxametallacycle as the active intermediate in ethylene epoxidation; expansion of the epoxide ring to incorporate surface silver atoms forms the oxametallacycle species. Oxametallacycles have been isolated by ring-opening ethylene oxide on Ag(111) and Ag(110), 1-epoxy-3-butene on Ag(111) and Ag(110), styrene oxide on Ag(111) and Ag(110) and isoprene oxide and propylene oxide on Ag(110). Surface science techniques and Density Functional Theory (DFT) were used in this study to investigate the interactions of styrene oxide and isoprene oxide with the Ag(110) surface, as well as the interactions of ethylene oxide and propylene oxide with the clean and O-covered Ag(110) surfaces. TPD experiments demonstrate that the styrene oxide ring opens at the substituted carbon, and DFT calculations indicate that the phenyl ring of the resulting oxametallacycle is oriented nearly parallel to the Ag(110) surface. Interaction of the phenyl group with the silver surface stabilizes this intermediate relative to that derived from the mono-olefin epoxide, ethylene oxide. During TPD, the oxametallacycle undergoes ring closure to reform styrene oxide and isomerization to phenylacetaldehyde at 505 K on Ag(110). Styrene oxide-derived oxametallacycles exhibit similar ring-closure behavior on the Ag(111) surface. Isoprene oxide also forms a strongly bound oxametallacycle intermediate on the Ag(110) surface. The oxametallacycle undergoes ring-closure to reform isoprene oxide in two peaks at 320 and 460 K when synthesized by epoxide adsorption at low temperatures. Epoxide doses at higher surface temperatures (ca. 300 K) lead to isomerization of the oxametallacycle and desorption of the aldehyde isomer, 2-methyl-2-butenal, in a single peak at 460 K. This work represents the first demonstration of a surface oxametallacycle species derived from an allylic epoxide. Similar to oxametallacycles derived from the non-allylic epoxides, isoprene oxide ring opens at the carbon bound to the unsaturated vinyl and methyl substituent groups to form a linear oxametallacycle on the Ag(110) surface. The structure of the isoprene oxide-derived oxametallacycle resembles that formed from ring-opening its non-allylic counterpart, 1-epoxy-3-butene, on Ag(110), according to DFT calculations. Following adsorption at 250 K on both clean and O-covered Ag(110), ethylene oxide ring-opens to form a stable oxametallacycle. On the clean Ag(110) surface, the oxametallacycle reacts to reform the parent epoxide at 280 K during TPD, while the aldehyde isomer, acetaldehyde, is observed at higher oxametallacycle coverages. In the presence of coadsorbed oxygen atoms, a portion of the oxametallacycles dissociate to release ethylene. However, of those that react to form oxygen-containing products, the fraction forming ethylene oxide is similar to that on the clean surface. The acetaldehyde product of oxametallacycle reactions combusts via formation of acetate species; the acetates react to form CO 2 at temperatures as low as 360 K on the O-covered surface. No evidence was observed for other combustion channels. This work provides experimental evidence for the connection of oxametallacycles to combustion via acetaldehyde formation, as well as to ring-closure to form ethylene oxide. Adsorption of propylene oxide at 120 K with subsequent flash of the surface to 230 K prior to TPD leads to the formation of a stable oxametallacycle on both the clean and O-covered Ag(110) surfaces; the oxametallacycle then undergoes ring-closure to reform propylene oxide at 250 K during TPD. The selectivity to propylene oxide decreases at higher oxametallacycle coverages where acetone and allyl alcohol are formed; carbon dioxide is also formed near 250, 350, and 450 K from reactions of the oxametallacycle and its products on the O-covered surface. At higher oxametallacycle coverages, additional higher temperature desorptions are observed at 300 and 400 K; the product distributions in these peaks are the same as that in the 250 K peak. Similar to reactions of ethylene oxide on the O-covered Ag(110) surface, the same fraction of oxametallacycle species reacts to form propylene oxide in the presence of co-adsorbed oxygen as that on the clean surface, although the coverage of oxametallacycles is 10-20% higher on the O-covered surface. The principal effects of co-adsorbed oxygen are to increase the capacity of the surface and to open an additional combustion pathway to CO 2 . The oxametallacycle undergoes combustion through a propionaldehyde species. This work represents the first time that an oxametallacycle has been linked to propylene oxide production.
Download or read book Enantioselective Organocatalysis written by Peter I. Dalko and published by John Wiley & Sons. This book was released on 2007-06-27 with total page 559 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this reference leaders at the forefront of research provide an insight into one of the hottest topics in organic synthesis, focusing on the most important enantioselective reactions. Clearly structured, each entry begins with a concise introduction, including a mechanistic discussion of the reaction, followed by preparative guidelines for newcomers, such as carefully selected working procedures with critical notes for bench chemists, rules of thumb and tips and tricks.
Download or read book The Development of Asymmetric Catalytic Reactions written by Bridget Debora Brandes and published by . This book was released on 1998 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
