In the course of nearly every program of research in organic chemistry, the investigator finds it necessary to use several of the better-known synthetic reactions. To discover the optimum conditions for the application of even the most familiar one to a compound not previously subjected to the reaction often requires an extensive search of the literature; even then a series of experiments may be necessary. When the results of the investigation are published, the synthesis, which may have required months of work, is usually described without comment. The background of knowledge and experience gained in the literature search and experimentation is thus lost to those who subsequently have occasion to apply the general method. The student of preparative organic chemistry faces similar difficulties. The textbooks and laboratory manuals furnish numerous examples of the application of various syntheses, but only rarely do they convey an accurate conception of the scope and usefulness of the processes.

For many years American organic chemists have discussed these problems. The plan of compiling critical discussions of the more important reactions thus was evolved. The volumes of Organic Reactions are collections of chapters each devoted to a single reaction, or a definite phase of a reaction, of wide applicability. The authors have had experience with the processes surveyed. The subjects are presented from the preparative viewpoint, and particular attention is given to limitations, interfering influences, effects of structure, and the selection of experimental techniques. Each chapter includes several detailed procedures illustrating the significant modifications of the method. Most of these procedures have been found satisfactory by the author or one of the editors, but unlike those in Organic Syntheses, they have not been subjected to careful testing in two or more laboratories. Each chapter contains tables that include all the examples of the reaction under consideration that the author has been able to find. It is inevitable, however, that in the search of the literature some examples will be missed, especially when the reaction is used as one step in an extended synthesis. Nevertheless, the investigator will be able to use the tables and their accompanying bibliographies in place of most or all of the literature search so often required. Because of the systematic arrangement of the material in the chapters and the entries in the tables, users of the books will be able to find information desired by reference to the table of contents of the appropriate chapter. In the interest of economy, the entries in the indices have been kept to a minimum, and, in particular, the compounds listed in the tables are not repeated in the indices.

The success of this publication, which will appear periodically, depends upon the cooperation of organic chemists and their willingness to devote time and effort to the preparation of the chapters. They have manifested their interest already by the almost unanimous acceptance of invitations to contribute to the work. The editors will welcome their continued interest and their suggestions for improvements in Organic Reactions.

In the intervening years since “The Chief” wrote this introduction to the second of his publishing creations, much in the world of chemistry has changed. In particular, the last decade has witnessed a revolution in the generation, dissemination, and availability of the chemical literature with the advent of electronic publication and abstracting services. Although the exponential growth in the chemical literature was one of the motivations for the creation of Organic Reactions, Adams could never have anticipated the impact of electronic access to the literature. Yet, as often happens with visionary advances, the value of this critical resource is now even greater than at its inception.

From 1942 to the 1980's the challenge that Organic Reactions successfully addressed was the difficulty in compiling an authoritative summary of a preparatively useful organic reaction from the primary literature. Practitioners interested in executing such a reaction (or simply learning about the features, advantages, and limitations of this process) would have a valuable resource to guide their experimentation. As abstracting services, in particular Chemical Abstracts and later Beilstein, entered the electronic age, the challenge for the practitioner was no longer to locate all of the literature on the subject. However, Organic Reactions chapters are much more than a surfeit of primary references; they constitute a distillation of this avalanche of information into the knowledge needed to correctly implement a reaction. It is in this capacity, namely to provide focused, scholarly, and comprehensive overviews of a given transformation, that Organic Reactions takes on even greater significance for the practice of chemical experimentation in the 21^st century.

Adams' description of the content of the intended chapters is still remarkably relevant today. The development of new chemical reactions over the past decades has greatly accelerated and has embraced more sophisticated reagents derived from elements representing all reaches of the Periodic Table. Accordingly, the successful implementation of these transformations requires more stringent adherence to important experimental details and conditions. The suitability of a given reaction for an unknown application is best judged from the informed vantage point provided by precedent and guidelines offered by a knowledgeable author.

As Adams clearly understood, the ultimate success of the enterprise depends on the willingness of organic chemists to devote their time and efforts to the preparation of chapters. The fact that, at the dawn of the 21^st century, the series continues to thrive is fitting testimony to those chemists whose contributions serve as the foundation of this edifice. Chemists who are considering the preparation of a manuscript for submission to Organic Reactions are urged to contact the Editor-in-Chief.

Richard F. Heck

August 15, 1931–October 10, 2015

Richard F. Heck, a giant in the field of organic chemistry, died on October 9, 2015. Beginning in the late 1950's, Heck envisioned that as the art of organic synthesis grew there would be a need for catalytic, organometallic-mediated bond-forming reactions that were tolerant of a wide range of functional groups. Research investigations led him to the Pd(0)/Pd(II) cycle of oxidative addition and reductive elimination, by which carbon-X bonds are catalytically converted to carbon-carbon and carbon-heteroatom bonds. His investigations laid the groundwork for all catalytic, organometallic, bond-forming processes that are used currently in modern organic synthesis.

The epic importance of catalytic palladium-mediated, carbon-carbon bond formation only slowly became apparent to the organic synthesis community. When his Organic Reactions chapter appeared in 1982, coverage of all the literature required only 45 pages (including tables!). By 2002, applications of his chemistry in synthesis had grown to the extent that the Organic Reactions chapter published that year, limited to the subset of intramolecular Heck Reactions, covered 377 pages. Moreover, the original 45 page chapter, despite its size, it is the most highly cited chapter in the Organic Reactions series with over 1500 citations!

Professor Heck received number of awards for his seminal contributions to chemistry, most notably sharing the Chemistry Nobel Prize in 2010. Among his many professional activities, he served as a member of the Editorial Board of Organic Reactions, Inc. from 1973–1985.

On a personal note, Dick Heck had already been publishing on palladium-catalyzed carbon-carbon bond formation for ten years, at the time that I joined the chemistry faculty of the University of Delaware in 1982. It was apparent that the intramolecular Heck reaction could be a powerful transformation. I sketched out some possible applications to Dick and offered to help his students, but he was not interested. He preferred to continue exploring new reactivity, initiating both “Suzuki coupling” and the “Sonogashira reaction”. Although he was the first to fully characterize a π-allylmetal complex and to elucidate the mechanism of cobalt-catalyzed alkene hydroformylation, he most enjoyed discussing the addition of formate to the palladium-catalyzed carbonylation reaction, leading to the formation of aldehydes. Even in retirement, Dick was eager to keep up with the literature, so I would send a selection of the most interesting articles every few months. He found the Catellani protocol particularly intriguing. He had thought that the carbon-palladium bond would be far too labile to allow such cascade transformations.

Dick is remembered for the key role he played as a pioneer in applying transition metal catalysis to the synthesis of complex organic molecules, both in academics and in industry. Before Grubbs, Schrock, Buchwald or Hartwig–indeed, before Stille, Suzuki, Negishi, Tsuji, Trost or Sonogashira–there was Heck pointing the way. From the late 1950's on, his contributions provided the creative spark that ignited this essential subdiscipline of synthetic methodology. In the words of Professor E. J. Corey: “Of all the individuals who have contributed to the spectacular progress in palladium catalyzed synthesis, there is no one whose work is as seminal or significant than that of Richard F. Heck.”

Douglass F. Taber, University of Delaware
November 10, 2015