The rate of advance in areas of science is seldom constant. Usually certain fields effloresce with activity because of the ealization that solutions are possible to long standing important problems. So it is now with asymmetric catalysis, a field which promises to change profoundly the strategic thinking of synthetic chemists. As this Report will show, reagents which can induce catalytic enantiocontrol of chemical transformations could represent the ultimate synthetic method. Nearly all synthetic strategies of complex molecules involve steps which require enantiocontrol and, in many cases, a specific catalytic transformation embodying enan tiocontrol has enormous advantages in terms of the rate and economy of the reaction. Because asymmetric catalysis is in a formative stage, workers with different backgrounds have joined the field. This Workshop had representatives with organometallic, organic, structural, kinetic, enzymatic, microbiological and industrial backgrounds. Each had his own perspective and this Report represents a consensus of this group of eleven people. The result is probably as compre hensive and balanced a view of the subject as is possible at present. It is hoped that those who have until now had but a glancing interest in asymmetric catalysis will find this Report a useful indication of its present state. We believe that asymmetric catalysis will have an increasing impact on the development of chemistry and will eventually dominate much of synthetic and industrial chemistry."

The literature contains tens of thousands of publications and patents devoted to the synthesis, characterization and processing of polymers. Despite the fact that there are more than one hundred elements, the majority of these publications and patents concern polymers with carbon backbones. Furthermore, the limited (by comparison) number of publications on polymers that contain elements other than carbon in their backbones are typically devoted to polymers based on silicon, especially those with Si-O bonds. This disparity is partially a consequence of the dearth of low cost organometallic feedstock chemicals potentially useful for polymer synthesis. It also derives from the lack of general synthetic techniques for the preparation of organometallic polymers. That is, by comparison with the numerous synthetic strategies available for the preparation of organic polymers, there are few such strategies available for synthesizing tractable, organometallic polymers. In recent years, commerical and military performance requirements have begun to challenge the performance limits of organic polymers. As such, researchers have turned to organometallic polymers as a possible means of exceeding these limits for a wide range of applications that include: (1) microelectronics processing (e.g. photoresists) [1]; (2) light weight batteries (conductors and semi-conductors) [2]; (3) non-linear optical devices [3] and, (4) high temperature structural materials (e.g. ceramic fiber processing) [4,5].

Organic chemistry is constantly concerned with effecting reactions at a particular centre in a complex molecule, and if possible with a high and predictable level of stereoselectivity. In the light of much accumulated ex perience within organic chemistry it is usually possible to assess the likeli hood of alternative reaction pathways at least qualitatively. However, well based expectations can be falsified, and the experiments directed to the synthesis of vitamin B12 which led to Woodward's recognition of orbital symmetry control in organic chemistry are an instructive example. Our limi tations in this respect are very much accentuated in the case of hetero geneous reactions, which present additional problems, and except for very well studied instances, heterogeneous catalysis has remained a relatively empirical area of chemistry. Knowledge in this area has, however, been greatly improved by the development of transition metal complexes which replicate the catalytic properties of the metals, and are effective in a homo geneous reaction system. This development has advanced our understanding of catalysis by making it possible to interpret reactions in strictly molecular terms. In addition, these homogeneously active complexes are frequently more selective than their heterogeneous metallic counterparts either in discriminating between different functional centres in a molecule or in of fering better stereoselectivity. Homogeneous catalysts have now been devised for a number of organic chemical reactions, including hydrogenation, carbonylation, polymerisa tion, and isomerisation and dismutation of alkenes."

Another approach is via the peracid route [10,Il], whereby propylene is epoxidized by an organic peracid, usually peracetic acid. The latter is prepared either by reaction of acetic acid with hydrogen peroxide, or by autoxidation of acetaldehyde. - (3) - (4) ---I...MeC0 H MeCHO +02 3 /'\. (5) MeC0 H + MeCH=CH ---I ...MeCH-CH + MeC0 H 3 2 2 2 Although this method has been extensively studied [10, II] and is often the method of choice for laboratory scale preparations of epoxides, it has not been widely applied on a commercial scale. The reasons are probably to be found in the hazards associated with the handling of these explosive and corrosive peracids on an industrial scale. Nevertheless, several companies continue to groom this method for future commercialization [12]. With organic hydroperoxides becoming available as commercial chemicals, in the last decade propylene oxide process technology has seen the commercializa- tion of the hydroperoxide route. Such a process, developed by Halcon Interna- tional and Atlantic Richfield, is that often referred to as the Halcon or Oxirane process [13]. It involves the reaction of propylene with an alkyl hydroperoxide in the presence of a soluble, metal catalyst (usually a molybdenum compound). The alkyl hydroperoxide is prepared by autoxidation of an appropriate hydro- carbon. For example, tert-butyl hydroperoxide (TBHP) is prepared by autoxida- tion of isobutane. (6) Reaction with propylene gives propylene oxide and tert-butanol as a coproduct.

As nucleophiles, simple alkenes are typically so unreactive that only highly active electrophiles, such as carbocations, peroxides, and halogens will react with them. For the generation of carbon-carbon bonds, milder methods will often be required. Fortunately, it is possible to increase the reactivity of alkene-type p-nucleophiles by introducing electron-donating substituents. Substitution of one H with an OH or OR gives an enol or a vinyl ether, which are already much better nucleophiles. Using nitrogen instead of oxygen, one obtains even better nucleophiles, enamines. Enamines are among the most reactive neutral carbon nucleophiles, exhibiting rates that are even comparable to some charged nucleophiles, such as enolates [1, 2]. Most enamines, unfortunately, are sensitive to hydrolysis. The parent enamine, N,N-dimethylvinylamine, has in fact been prepared [3], but appears to be uns- ble. Enamines of cyclic ketones and many aldehydes can readily be isolated, however [4-7]. The instability of enamines might at first appear to diminish the utility of enamines as nucleophiles, but actually this property can be viewed as an added benefit: enamines can be readily and rapidly generated catalytically by using a suitable amine and a carbonyl compound. The condensation of aldehydes or ketones with amines initially affords an imine or iminium ion, which then rapidly loses a proton to afford the corresponding enamine (Scheme 1).

This book analyzes conventional fixed-bed reactors such as trickle-bed, bubble (packed) column, and multitubular reactors with regard to process efficiency, design and safety. It is shown that these reactors do not possess any substantial potential for improving industrial processes. Modern concepts in mass transfer, kinetics and process design are applied to process development. In light of the given analysis, new approaches to the development of technologies based on innovative principles are elucidated. For the first time, first-hand knowledge about Two-Zone Model, Oscillation Theory, map of the energy dissipation is presented in full.

Olefin metathesis reaction can be considered as one of the most successful organic reactions with many applications in the low molecular weight range and also in the polymer field. The use of catalysts with their selective and effective transformation properties in olefin metathesis I polymerization systems is a growing interest. There has been great effort and competition in developing active and commercially useful catalysts. The main aim of this ASI was to gather several research groups and also the people from industry. to present existing knowledge and latest results in the field. A wide range of topics through homogeneous and heterogeneous aspects have been considered. Attention has been drawn to the metal-carbene and metallacyclobutane complexes as active species, the initiation mechanisms, the stereochemistry and thermodynamics of these reactions. New catalytic systems for the metathesis of alkenes and alkynes and fot' ring opening polymeriZation I block copolymerization reactions have been introduced. Spectroscopic studies for the characteriZation of catalysts, simulation studies explaining the function of chain carrier species and polymer degradation have also been covered. A detailed industrial report concerning the patents and applications in olefin metathesis I cyc1001efin polymerization area, fabrication and derivation has been presented. This volume contains the main lectures and seminars given at the NATO Advanced Study Institute on " Olefin Metathesis and Polymerization Catalysts: Synthesis, Mechanism and Utilization," held at Akcay. Babkesir. Turkey between 10th and 22nd September 1989.

In the last 15 years aqueous organometallic chemistry and catalysis has emerged from being a laboratory curiosity to become an established field of research. Topics reviewed here include mechanistic studies on the effect of water on catalyzed reactions, the preparation of water soluble phosphines as ligands for catalysis, metal catalyzed organic reactions in water (hydrogenation, hydroformylation, carbonylation, olefin metathesis, hydrophosphination, etc.), chiral ligands and enantioselective catalysis, organometallic radical photochemistry in aqueous solutions, bioorganometallic chemistry, organometallic reactions of biopolymers, and catalytic modification of biomembranes. The summary of recent results is supplemented by an assessment of probable future research trends. Audience: Researchers in both academia and industry, as well as graduate students of homogeneous catalysis.

Barry Trost: Transition metal catalyzed allylic alkylation.- Jeffrey W. Bode: Reinventing Amide Bond Formation.- Naoto Chatani and Mamoru Tobisu: Catalytic Transformations Involving the Cleavage of C-OMe Bonds.- Gregory L. Beutner and Scott E. Denmark: The Interplay of Invention, Observation and Discovery in the Development of Lewis Base Activation of Lewis Acids for Catalytic Enantioselective Synthesis.- David R. Stuart and Keith Fagnou: The Discovery and Development of a Palladium(II)-Catalyzed Oxidative Cross-Coupling of Two Unactivated Arenes.- Lukas Goossen and Kathe Goossen: Decarboxylative Cross-Coupling Reactions.- A. Stephen K. Hashmi: Gold-Catalyzed Organic Reactions.- Ben List: Developing Catalytic Asymmetric Acetalizations.- Steven M. Bischof, Brian G. Hashiguchi, Michael M. Konnick, and Roy A. Periana: The De NovoDesign of CH Bond Hydroxylation Catalysts.- Benoit Cardinal-David, Karl A. Scheidt: Carbene Catalysis: Beyond the Benzoin and Stetter Reactions.- Kenso Soai and Tsuneomi Kawasaki: Asymmetric autocatalysis of pyrimidyl alkanol.- Douglas C. Behenna and Brian M. Stoltz: Natural Products as Inspiration for Reaction Development: Catalytic Enantioselective Decarboxylative Reactions of Prochiral Enolate Equivalents. Hisashi Yamamoto: Acid Catalysis in Organic Synthesis.

Homogeneous catalysis plays an important role both in the laboratory and in the industry. Successful applications in industry involve new polymerisation processes with complexes of zirconium and related metals, new carbonylation processes employing palladium and rhodium, ring opening polymerisations, and new enantioselective isomerisation catalysts as in the preparation of menthol. Also in the synthesis of organic compounds in the laboratory highly selective homogeneous catalysts represent an irreplaceable part of the toolbox of the synthetic chemist. Examples of such reactions are cross-coupling (Ni, Pd), nucleophilic substitution of allylpalladium complexes, Heck reactions (Pd), asymmetric epoxidation, Wacker type reactions (Pd), asymmetric hydrogenations (Rh, Ru), reactions of chromium complexes, enantioselective reactions with Lewis acids, reactions with the McMurry reagent, etc. There is hardly any multistep organic synthesis that does not involve one of these metal catalysed reactions. Most of these catalysts have been developed by empiricism. The metal catalysed processes consist of a series of elementary steps which often have been studied in isolation in organometallic chemistry. The knowl- edge of such elementary steps - effect ofligands, anions, coordination number, valence states - has greatly contributed to the development of improved cata- lysts for the reactions mentioned above. In addition to the empirical approach theoretical methods have given support and guidance to the development of improved processes. Often the key steps of a cycle escape from a direct ob- servation and then theoretical contributions are even more wanted.

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.

Organic chemistry has played a vital role in the development of diverse molecules which are used in medicines, agrochemicals and polymers. Most ofthe chemicals are produced on an industrial scale. The industrial houses adopt a synthesis for a particular molecule which should be cost-effective. No attention is paid to avoid the release of harmful chemicals in the atmosphere, land and sea. During the past decade special emphasis has been made towards green synthesis which circumvents the above problems. Prof. V. K. Ahluwalia and Dr. M. Kidwai have made a sincere effort in this direction. This book discusses the basic principles of green chemistry incorporating the use of green reagents, green catalysts, phase transfer catalysis, green synthesis using microwaves, ultrasound and biocatalysis in detail. Special emphasis is given to liquid phase reactions and organic synthesis in the solid phase. I must congratulate both the authors for their pioneering efforts to write this book. Careful selection of various topics in the book will serve the rightful purpose for the chemistry community and the industrial houses at all levels. PROF. JAVED IQBAL, PhD, FNA Distinguished Research Scientist & Head Discovery Research Dr. Reddy's Laboratories Ltd.

Metal-Ligand Interactions - Structure and Reactivity emphasizes the experimental determination of structure and dynamics, supported by the theoretical and computational approaches needed to establish the concepts and guide the experiments. Leading experts present masterly surveys of: clusters, inorganic complexes, surfaces, catalysis, ab initio theory, density functional theory, semiempirical methods, and dynamics. Besides the presentations of the fields of study themselves, the papers also bring out those aspects that impinge on, or could benefit from, progress in other disciplines. Refined in the fire of an interactive and stimulating conference, the papers presented here represent the state of the art of current research.

There are only few topics in organometallic chemistry, which have stimulated research activities in as many areas, as transition-metal carbene (alkylidene) complexes. About 25 years after the first planned synthesis of a carbene complex in E.O. Fischer's laboratory in Munich the NATO Advanced Research Workshop on Transition-Metal Carbene Complexes was the first meeting which, brought together scientists from different disciplines to discuss inorganic, organic, theoretical structural catalysis-related aspects of metal carbene chemistry. The 70th birthday of Professor E.O. Fischer was a good occasion for this enterprise. The organizers of the meeting (K.D. Dotz, Marburg; F.R. KreiBl, Munchen; U. Schubert, Wurzburg) were encouraged by the fact that most of the leading scientists in this area were able to participate in the workshop. The very high standard of the contributions is reflected in this book, which contains papers from the majority of the participants. The Proceedings show the state of the art in metal carbene chemistry and will hopefully be a landmark in the development of this area of chemistry. Generous financial support for the workshop and for the preparation of this book was provided by the Scientific Affairs Division of NATO and some companies. The organizers also acknowledge the efforts of the staff of the Bildungs zentrum der Hans-Seidel-Stiftung in Wild bad Kreuth for creating a pleasant and stimulating atmosphere during the conference."

The origins of the petrochemical industry can be traced back to the 1920s when simple organic chemicals such as ethanol and isopropanol were first prepared on an industrial scale from by-products (ethylene and propylene) of oil refining. This oil-based petrochemical industry, with lower olefms and aromatics as the key building blocks, rapidly developed into the enormous industry it is today. A multitude of products that are indispensible to modern day society, from plastics to pharmaceuticals, are derived from oil and natural gas-based hydro carbons. The industry had its heyday in the '50s and '60s when predictions of future growth rates tended to be exponential curves. However, two developments that took place in the early '70s disturbed this simplistic and optimistic view of the future. Firstly, the publication of the report for the Cub of Rome on the 'Limits to Growth' emphasized the finite nature of non-renewable fossil fuel resources. Secondly, the Oil Crisis of 1973 emphasized the vulnerability of an energy and chemicals industry that is based largely on a single raw material."

Catalysts are now widely used in both laboratory and industrial-scale chemistry. Indeed, it is hard to find any complex synthesis or industrial process that does not, at some stage, utilize a catalytic reaction. The development of homogeneous transition metal catalysts on the laboratory scale has demonstrated that these systems can be far superior to the equivalent heterogeneous systems, at least in terms of selectivity. is an increasing interest in this field of research from both an Thus, there academic and industrial point of view. In connection with the rapid developments in this area, four universities from the E.E.C (Aachen, FRG; Liege, Belgium; Milan, Italy; and Lille, France) have collaborated to organise a series of seminars for high-level students and researchers. These meetings have been sponsored by the Commission of the E.E.C and state organizations. The most recent of these meetings was held in Lille in September 1985 and this book contains updated and expanded presentations of most of the lectures given there. These lectures are concerned with the field of homogeneous transition metal catalysis and its application to the synthesis of organic intermediates and fine chemicals from an academic and industrial viewpoint. The continuing petroleum crisis which began in the early 1970s has given rise to the need to develop new feedstocks for the chemical industry.

Well tailored metal catalysts are catalysts of the new generation resulting from scientific development at the boundary between homogeneous and hetero- geneous chemistry. The main factors involved in making tailored metal catalysts are not those of traditional impregnation in which the chemistry is in general unknown and ill-defined, or of simple ion exchange which involves long-range forces with little control on the local structure through definite and special bond direction. Tailored Metal Catalysts thus has a rather different emphasis from normal review publications in the field of catalysis. Here we concentrate more on the distinct surface chemistry and catalytic properties of important established materials with well-characterized active structures or precursors, although at the same time providing a systematic presentation of relevant data. Many pioneering works have been undertaken in the field of tailored metal catalysts since the early research on polymer-attached homogeneous metal complexes by the British Petroleum Company Ltd. and the Mobil Oil Corpora- tion around 1969; transition metal complexes attached on polymers by Grubbs (1971), Heinemann (1971), Manassen (1971), Pittman (1971), Bursian et al. (1972), Kagan (1973), Bailar (1974); transition metal complexes attached on inorganic oxides by Allum et al. (1972), Ballard (1973), Candlin and Thomas (1974), Murrell (1974), Yermakov (1974); metal carbonyls/polymers by Moffat (1970); metal carbonyls/inorganic oxides by Parkyns (1965), Davie et al. (1969), Banks et al. (1969), Howe (1973), Burwell (1975); metal carbonyl clusters/ polymers by Colhnan (1972); metal carbonyl clusters/inorganic oxides by Robertson and Webb (1974), Anderson (1974), Smith et al. (1975).

Over the past 20 years aqueous organometallic catalysis has found applications in small- scale organic synthesis in the laboratory, as well as in the industrial production of chemicals with a combined output close to one million tons per year. Aqueous/organic two-phase reactions allow easy product-catalyst separation and full catalyst recovery which mean clear benefits not only in economic but also in environmental and green chemistry contexts. Instead of putting together a series of expert reviews of specialized fields, this book attempts to give a comprehensive yet comprehensible description of the various catalytic transformations in aqueous systems as seen by an author who has been working on aqueous organometallic catalysis since its origin. Emphasis is put on the discussion of differences between related non-aqueous and aqueous processes due to the presence of water. The book will be of interest to experts and students working in catalysis, inorganic chemistry or organic synthesis, and may serve as a basis for advanced courses.

Heterogeneous catalysis provides the backbone of the world's chemical and oil industries. The innate complexity of practical catalytic systems suggests that useful progress should be achievable by investigating key aspects of catalysis by experimental studies on idealised model systems. Thin films and supported clusters are two promising types of model system that can be used for this purpose, since they mimic important aspects of the properties of practical dispersed catalysts. Similarly, appropriate theoretical studies of chemisorption and surface reaction clusters or extended slab systems can provide valuable information on the factors that underlie bonding and catalytic activity. This volume describes such experimental and theoretical approaches to the surface chemistry and catalytic behaviour of metals, metal oxides and metal/metal oxide systems. An introduction to the principles and main themes of heterogeneous catalysis is followed by detailed accounts of the application of modern experimental and theoretical techniques to fundamental problems. The application of advanced experimental methods is complemented by a full description of theoretical procedures, including Hartree-Fock, density functional and similar techniques. The relative merits of the various approaches are considered and directions for future progress are indicated.

The development of "high-tech" materials in contemporary industries is deeply related to a detailed understanding of specific surface properties of catalysts which make particular reactions possible. But this understanding presupposes that there exists a body of theory capable of explaining situations not easily accessible to experimental methods and of relating experimental findings among themselves and with theoretical constructs. For these reasons, theoretical developments in surface physics and surface chemistry of transition metal compounds have been of paramount importance in promoting progress in catalysis, electronic devices, corrosion, etc. Although a great variety of spectroscopic methods for analyzing solids and surfaces at molecular scale have been introduced in recent years, nevertheless, many questions about the adsorption sites and intermediates, the effect of promoters, the poisoning of active sites, the nature of segregation of impurities, the process of surface reconstruction, the mechanisms of reactions, etc. have remained unanswered simply because of the great complexity of surface phenomena. It is in this sense that quantum mechanical method- combined with experimental data - may shed some light on the microscopic properties of new surface materials.

Homogeneous hydrogenation is one of the most thoroughly studied fields of homogeneous catalysis. The results of these studies have proved to be most important for an understanding of the underlying principles of the activation of small molecules by transition metal complexes. During the past three decades homogeneous hydrogenation has found widespread application in organic chemistry, including the production of important pharmaceuticals, especially where a sophisticated degree of selectivity is required. This volume presents a general account of the main principles and applications of homogeneous hydrogenation by transition metal complexes. Special attention is devoted to the mechanisms by which these processes occur, and the role of the recently discovered complexes of molecular hydrogen is described. Sources of hydrogen, other than H2, are also considered (transfer hydrogenation). The latest achievements in highly stereoselective hydrogenations have made possible many new applications in organic synthesis. These applications are documented by giving details of the reduction of important unsaturated substrates (alkenes, alkynes, aldehydes and ketones, nitrocompounds, etc.). Hydrogenation in biphasic and phase transfer catalyzed systems is also described. Finally, a discussion of the biochemical routes of H2 activation highlights the similarities and differences in performing hydrogenation in both natural and synthetic systems. For researchers working in the fields of homogeneous catalysis, especially in areas such as pharmaceuticals, plastics and fine chemicals.

Continuously increasing oil prices, a dwindling supply of petroleum, and the existence of extensive reserves of biomass, especially of coal, have given rise to a growing interest in generating CO/H from these sources. Catalytic reactions can 2 convert CO/H mixtures to useful hydrocarbons or hydrocarbon intermediates. 2 There is little doubt that petroleum will remain the backbone of the organic chemical industry for many years to come, yet there is great opportunity for CO as an alternative feedstock at times when it is needed. The loosely defined body of chemistry and technology contained in these areas of development has become known as C 1 chemistry, embracing many C 1 building blocks such as CH , CO/H , CO, CH OH, CO and HCN; still emphasis 4 2 3 2 rests on carbon monoxide. Academic research laboratories, oil and chemical companies are in the vanguard of C 1 chemistry. The Japanese Ministry of International Trade and Industry is sponsoring a seven-year program of 14 major chemical companies in C 1 chemistry aimed at developing new technology for making basic chemicals from CO and H2 . It is likely that C 1 chemistry will develop slowly but persistently and the future holds great potential.

Since the first application of dendrimers in catalysis in the mid 1990s, this field has advanced rapidly. As a consequence, catalytically active dendrimers have emerged as a class of molecular catalysts that has substantially enriched the field of homogeneous (and in part heterogeneous) catalysis. A general survey of transition metal dendrimer catalysts and the way they have developed is followed by in-depth discussions of dendritic transition metal catalysis based on non-covalent catalyst-support interaction and an overview of the rapidly growing field of stereoselective dendrimer catalysis. The development of dendrimer-encapsulated bimetallic nanoparticles has provided the interface with heterogeneous colloid catalysis. As cheaper and readily accessible alternatives to regular dendrimers, hyperbranched polymers are increasingly being used as catalyst platforms. These topics are complemented by a review of metallodendritic exoreptors for the redox recognition of oxo-anions and halides.