Catalytic Hydrogenation In Organic Syntheses

Catalytic Hydrogenation in Organic Syntheses focuses on the process of catalytic hydrogenation in organic synthesis. This book gives the reader easy access to catalytic history, to show what can be done and how to do it. A variety of working generalities and common sense guides are given as aids in selecting catalytic metal, catalyst support, concentration of metal and catalyst, solvent, and reaction conditions. All manner of hydrogenation catalysts are considered and mechanisms of hydrogenation are presented at a level that is useful to the synthetic organic chemist. This volume is comprised of 15 chapters and begins with an overview of catalytic hydrogenation and heterogeneous hydrogenation catalysts, along with hydrogenation reactors and reaction conditions. The discussion then shifts to the hydrogenation of compounds such as acetylenes, olefins, aldehydes, ketones, nitriles, oximes, acids, esters, lactones, anhydrides, and nitro compounds as well as carbocyclic aromatics and heterocyclic compounds. The reader is also introduced to reductive alkylation, catalytic dehydrohalogenation, and hydrogenolysis of small rings. A chapter on miscellaneous hydrogenolyses concludes the book. This book will be of interest to organic chemists working in the field of catalytic hydrogenation.

Based on over 22 years of experience, this book presents a substantial accumulation of knowledge. Clearly and understandably written, it gives detailed descriptions of many experiments, providing step-by-step procedures along with personal notes and observations, directions, suggestions, and safety precautions. The yields obtained in these experiments are good to excellent, and most of the hydrogenations discussed are carried out under very mild conditions.

Catalysis in Organic Syntheses contains the proceedings of the Seventh Conference on Catalysis in Organic Syntheses held in Chicago, 5-7 June 1978. The conference was sponsored by The Organic Reactions Catalysis Society, an affiliate of The Catalysis Society. Most of the papers reflect the main interest of the Society membership, namely, the application of catalysis as a tool for the synthetic organic chemist rather than studies of catalytic phenomena per se, the latter subject being amply covered in other symposia. It is not surprising then that the largest group of papers deal with catalytic hydrogenation, the catalytic reaction most often encountered in organic synthesis. Other subjects in the burgeoning field of catalysis are not neglected however, as evidenced by papers on the spectroscopic evaluation of catalysts, homogenous catalysis by organometallic complexes, and the catalysis of coal conversion. Finally a group of papers explore some safety considerations in performing catalytic transformations.

A complete guide to the most important reduction method in organic synthesis The most comprehensive reference in the field, Handbook of Heterogeneous Catalytic Hydrogenation for Organic Synthesis provides synthetic chemists and chemical engineers in fine chemicals and pharmaceuticals with detailed experimental guidelines for heterogeneous catalytic hydrogenation. Organized by functional groups for ready reference and featuring detailed examples of hundreds of reactions, this handbook covers hydrogenations of alkenes, alkynes, aldehydes and ketones, nitriles, imines, nitro and nitroso compounds, carboxylic acids and esters, and aromatic and heterocyclic compounds. In addition, coverage includes the preparation of amines by reductive alkylation and the hydrogenolysis of a variety of compounds. Examples of hydrogenation of functional groups and reaction pathways are illustrated with numerous equations and schemes. Practitioners will appreciate the plenitude of experimental details given for most of the reactions selected, including amounts of reagents and catalysts, reaction temperatures, hydrogen pressures, and reaction times. They will also find helpful the more than one hundred tables included throughout the book detailing the effects of key factors governing rate and selectivity, such as compound structure, the nature of catalysts and supports, and the nature of solvents. Researchers will benefit from the introductory chapters covering an array of hydrogenation catalysts, including nickel, cobalt, copper, iron, platinum group metals, rhenium, and other oxide and sulfide catalysts, as well as reactors and reaction conditions.

The features of this book which will be of special interest to academic organic chemists are the introduction (Chapter 1), which presents a short course on the concepts and language of heterogeneous catalysis, covers organic reaction mechanisms of hydrogenation (Chapter 2), hydrogenolysis (Chapter 4), and oxidation (Chapter 6), a presents problems and solutions specific for running heterogeneous catalytic organic reactions in solution. These materials can supplement advanced chemistry courses. Most synthetic organic chemists use a variety of "protecting groups" which they attach to functional groups (reactive groups of atoms) while some reaction is being conducted on another part of the molecule. These protecting groups prevent reactions of the functional groups during other reactions and are removed later by a heterogeneous catalytic method called hydrogenolysis. One unique feature of this book, not found in other books on catalysis, is an exhaustive chapter (Chapter 4) on hydrogenolysis, which is dredged from the recent synthetic literature published by modern organic chemists. Academic organic chemists should find this chapter extremely useful and may wish to adopt the book as a supplement for advanced organic chemistry courses designed for seniors and for graduate students. It will also be useful for professors and their research groups engaged in synthetic organic chemistry. Many academic organic chemists are not aware of recent advances in heterogeneous enantioselective catalysis (Chapter 3) or in selective low temperature, liquid phase heterogeneous catalytic oxidations by hydrogen peroxide (Chapter 6). These specialty topics are timely and may be new to academic organic chemists and can be used to supplement their advanced courses. Several features of this book will also be of special interest to industrial chemists who are unfamiliar with heterogeneous catalysis. Many good organic chemists are hire by industry. They synthesize a new compound using standard organic synthetic techniques but are informed by their supervisor that they must convert some of their synthetic steps into heterogeneous catalytic steps. They may not have been exposed to heterogeneous catalysis and have few places to turn. This book offers them a crash course in heterogeneous catalysis as well as many examples of reactions and conditions with which they can start their search. Those industrial organic chemists already familiar with heterogeneous catalysis will find this book useful as a reference to many examples in the recent literature. They will find recent surface science discoveries correlated with heterogeneous catalysis or organic reactions and mechanistic suggestions designed to stimulate innovative nontraditional thinking about organic reactions on surfaces. Written by organic chemists for organic chemists Introduces heterogeneous catalysis concepts and language Presents a comprehensive compilation of protecting group removal procedures Covers liquid-phase hydrogenations, hydrogenolysis, and oxidations Addresses heterogeneous methods for producing pure enantiomers of chiral products Examines the emerging field of heterogenized homogeneous catalysts Mixes practical applications with mechanistic interpretations

Catalytic reductions are among the most used synthetic transformations, and the past 15 years have seen great progress in this field. Science of Synthesis: Catalytic Reduction in Organic Synthesis includes the latest developments, as well as selective coverage of more well-established methods. Both heterogeneous and homogeneous catalytic systems are covered, and enantioselective methodology is well represented. There is a focus on the use of metal nanoparticles, both in suspension as well as on solid supports. Furthermore, the advent of research on the conversion of renewable resources into fuels and chemicals has given a great impetus to the field, as deoxygenations are often the first step in the conversion of biomass and this can often be achieved using hydrogenation or hydrogenolysis reactions. Scope, limitations, and mechanism of the reactions are discussed and key experimental procedures are included.

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.