Phase Transfer Catalysis

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.

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.

Phase Transfer Catalysis: Principles and Techniques outlines the theory, mechanism, and kinetics of the phase transfer catalysis (PTC) process. This book surveys the principal reaction types that have employed the PTC, including the typical experimental procedures for preparing catalysts and conducting representative types of chemical reactions. This compilation discusses the transfer of anions from aqueous to organic phases, macrocyclic ethers as phase transfer catalysts, halide displacement reactions, and Darzen’s reaction with chloroacetonitrile. The dihalocarbene insertion reactions into C-H bonds, Wittig reaction with aqueous sodium hydroxide, and phase transfer catalyzed oxidation and reduction reactions are also elaborated. This text likewise covers the deuterium exchange of active hydrogens and thiolation with organic thiocyanates. This publication is beneficial to chemists and students studying the principles and techniques related to PTC.

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.

E. V. Dehmlow, S. S. Dehmlow Phase Transfer Catalysis Third, Revised and Enlarged Edition Phase Transfer Catalysis has matured, and so has this book. Certain PTC-variants have become standard techniques in the lab, and PTC may be on the brink of large-scale use. The new edition describes important new developments in PTC. Furthermore, it has been extensively updated and offers a comprehensive list of very recent references. New material has been added on solid/liquid PTC enantioselective reactions metal-organic reactions reduction and oxidation reactions elimination and substitution reactions

The field of phase transfer catalysis is a tribute to the chemists involved in process development research. Phase transfer catalysis is a solution to numerous cost and yield problems encountered regularly in industrial laboratories. In fact, much of the early work in this area was conducted by industrial chemists although the work was not labelled phase transfer catalysis at the time. We certainly do not intend to minimize the contributions of academic chemists to this field, but it is an unalterable fact that much of the early understanding and many of the early advances came from industrial laboratories. A special tribute is due to Dr. Charles Starks of the Continental Oil Company. By the mid sixties, Starks had formulated the principles of phase transfer catalysis and had applied for patents on many reactions that others were later to examine in somewhat greater detail. His mechanistic model of phase transfer catalysis still stands up well today and is a model for much of the thinking in this area. It is fitting that Starks suggested the name "phase transfer catalysis" by which the whole field is now known. We wish to thank a number of people who have aided us in many ways in the preparation of this volume. We very much appreciate the helpful discussions and insights provided by Drs. Henry Stevens and Andrew Kaman of PPG Industries in Barberton, Ohio. We also thank Dr. L. A.

This text provides experimental methods for a wide range of organic reactions, systematically arranged according to reaction type, and describes the advantages and limitations of the procedures. Traditional methods to speed up organic reactions involve energy-consuming processes and costly and environmentally "unfriendly" solvents. Additionally, isolation of the product requires energy and time-consuming purification processes. A simple solution, especially for reactions involving anionic reactants, is the use of phase-transfer catalysis. Quaternary ammonium cations have the ability to transfer the anionic reactants as non-solvated ion-pairs from aqueous media into organic media. The resultant effect is to increase the rate of the organic reaction by enhancing the reactivity of the anionic species and increasing the encounter rate with the organic substrate. Side reactions are frequently eliminated so that the overall yield of the desired product is increased. Quaternary Ammonium Salts presents procedures for reducing reaction times and the need for extreme conditions, which are frequently encountered under standard reaction procedures. This is the only book to be published on quaternary ammonium salts. Best Synthetic Methods volumes allow the practicing synthetic chemist to choose between all the alternatives and assess their real advantages and limitations. Each volume of the series deals with a particular topic from a practical point of view, giving detailed examples and precise experimental directions and hints. With the emphasis on laboratory use, these volumes represent a comprehensive and practical guide to modern synthetic organic chemistry.

Explore and review novel techniques for intensifying transport and reaction in liquid-liquid and related systems with this essential toolkit. Topics include discussion of the principles of process intensification, the nexus between process intensification and sustainable engineering, and the fundamentals of liquid-liquid contacting, from an expert with over forty-five years' experience in the field. Providing promising directions for investment and for new research in process intensification, in addition to a unique review of the fundamentals of the topic, this book is the perfect guide for senior undergraduate students, graduate students, developers, and research staff in chemical engineering and biochemical engineering.