Edited by the leading expert on the topic, this is the first book to present the latest developments in this exciting field. Alongside the theoretical aspects, the top contributors provide practical protocols to give readers additional important information otherwise unavailable. A must for every synthetic chemist in academia and industry.
Edited by the leading expert on the topic, this is the first book to present the latest developments in this exciting field. Alongside the theoretical aspects, the top contributors provide practical protocols to give readers additional important information otherwise unavailable. A must for every synthetic chemist in academia and industry.
Phase transfer catalysis is a sophisticated chemical technique which can be used to perform a variety of chemical reactions under mild conditions and with improved control. Since the concept was developed, both the theoretical and practical synthetic applications have seen considerable development, to the point where the technique can be applied to many areas of chemistry. Thus, phase transfer methods are now utilized in many applications, from research chemistry to full-scale production, where the benefits of faster, cleaner and more selective reactions are required. In this new book, the editors have brought together a range of contributors, each of whom is working at the forefront of the technology, to provide a clear, concise and ahtoritative review of this important area of chemistry. Industrial and academic chemists working on the synthesis, scale-up, production or analysis of a wide range of chemical products will find this book an essential reference on phase transfer technology.
Edited by two of the experts in the field, the central aim is to show organic chemists working in process development that enantioselective catalysis is suitable for the large-scale production of enantioenriched intermediates. In so doing, it is equally a source of information and inspiration for academic research, and, with its contribution by Noble prizewinner W. S. Knowles, will also heighten the status of industrial catalyst specialists working in the exciting field of enantioselective catalysis. Some 25 contributions from top industrial researchers around the world present case studies on the development of the widest possible range of large-scale enantioselective processes, featuring stereoselective production processes of fine-chemicals, agrochemicals and pharmaceuticals. Clearly structured according to the nature of the task, this handbook adopts a problem-driven approach such that readers can easily find how colleagues have dealt with a similar situation.
Since 1971 when useful working concepts for the technique of phase-transfer catalysis (PTC) were introduced, the understanding, development, and applica tions of this method for conducting organic reactions has expanded exponentially. PTC has brought vast new dimensions and options to chemists and chemical engineers. From its use in less than ten commercial processes in 1975, PTC use has increased so that in the early 1990s it is involved in more than 600 industrial applications to manufacture products valued at between 10 and 20 billion U.S. dollars. PTC is widely used for simple organic reactions, steps in synthesis of pharmaceuticals, agricultural chemicals, perfumes, ftavorants, and dyes; for specialty polymerization reactions, polymer modifications, and monomer synthe sis; for pollution and environmental control processes; for analysis oftrace organic and inorganic compounds; and for many other applications. Often, PTC offers the best (and sometimes only) practical technique to obtain certain products. The authors experience in teaching a short course on phase-transfer catalysis has shown to us that a newcomer to PTC can easily be frustrated and confused by the large amount of information available in the literature and in patents. The purpose of this book, therefore, was to bring this information together in a logical and user-friendly way, without sacrificing matters of scholarly and fundamental importance.
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.
There are two main disciplines in catalysis research -- homogeneous and heterogeneous catalysis. This is due to the fact that the catalyst is either in the same phase (homogeneous catalysis) as the reaction being catalyzed or in a different phase (heterogeneous catalysis). Over the past decade, various approaches have been implemented to combine the advantages of homogeneous catalysis (efficiency, selectivity) with those of heterogeneous catalysis (stability, recovery) by the heterogenization of homogeneous catalysts or by carrying out homogeneous reactions under heterogeneous conditions. This unique handbook fills the gap in the market for an up-to-date work that links both homogeneous catalysis applied to organic reactions and catalytic reactions on surfaces of heterogeneous catalysts. As such, it highlights structural analogies and shows mechanistic parallels between the two, while additionally presenting kinetic analysis methods and models that either work for both homogeneous and heterogeneous catalysis. Chapters cover asymmetric, emulsion, phase-transfer, supported homogeneous, and organocatalysis, as well as in nanoreactors and for specific applications, catalytic reactions in ionic liquids, fluorous and supercritical solvents and in water. Finally, the text includes computational methods for investigating structure-reactivity relations. With its wealth of information, this invaluable reference provides academic and industrial chemists with novel concepts for innovative catalysis research.
Considering the challenge of sustainability facing our society in the coming decades, catalysis is without any doubt a research area of major importance. In this regard, asymmetric organocatalysis, now considered a pillar of green chemistry, deserves particular attention. The first chapter of this volume examines the topic of asymmetric organocatalysis in light of radical chemistry. Recent important progress in this field has been attained by promoting the formation and harnessing the high reactivity of open-shell intermediates. Merging organocatalysis with radical chemistry has been the key to solving some longstanding bottlenecks, and has also significantly contributed to reinforcing the key role of organocatalysis in asymmetric catalysis. This chapter presents the most significant developments in this area, with a particular focus on asymmetric SOMO- and photoredox-organocatalyzed transformations. Chapter 2 focuses on quaternary ammonium salts (R4N+X-), especially chiral derivatives, and their behavior as unique catalysts in organocatalysis. Forming chiral ion-pairs capable of promoting asymmetric reactions, they also operate as unique “transporters involved in phase transfer catalytic processes between liquid–liquid or liquid–solid systems. Furthermore, they offer unique opportunities when forming cooperative ion-paired entities R4N+X-, allowing a synergistic implication of the counter-ion X- either as Brønsted bases or Lewis bases. Specific design of such chiral catalysts in modern chemistry and better insight into their mode of activation facilitates efficient and unprecedented chemical transformations. This chapter provides an overview of the use of chiral quaternary ammonium salts in organocatalysis, emphasizing both general mechanistic aspects and the scope of this approach. Presents the most significant developments with a particular focus on asymmetric SOMO- and photoredox-organocatalyzed transformations Givies a larger overview of chiral ammonium salts in organocatalysis rather than a specific review dedicated to specialists in this area Affords a historical evolution of this field of research
