Robert Burns Woodward ( eng. Robert Burns Woodward ; April 10, 1917 , Boston , Massachusetts - July 8, 1979 , Cambridge , Massachusetts ) - American organic chemist [1] . He made a significant contribution to modern organic chemistry , especially in the synthesis and determination of the structure of complex natural products. He worked closely with Roald Hofman on theoretical studies of chemical reactions. Woodward - the winner of the Nobel Prize in Chemistry for 1965.
Robert Burns Woodward | |
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English Robert Burns Woodward | |
Date of Birth | April 10, 1917 |
Place of Birth | Boston , Massachusetts , United States |
Date of death | July 8, 1979 (62 years) |
Place of death | Cambridge , Massachusetts , United States |
A country | USA |
Scientific field | organic chemistry |
Place of work | Harvard University (since 1937) |
Alma mater | Massachusetts Institute of Technology (1936) |
Famous students | Robert M. Williams, Harry Wasserman , Yoshito Kishi, Stuart Schreber, William Rusch, , Kendall Hawk |
Awards and prizes | National Science Medal of the USA (1964) Nobel Prize in Chemistry ( 1965 ) Willard Gibbs Award (1967) |
Young years, education
Woodward was born in Boston , in the family of Margaret (born Burns), the daughter of a native of Scotland , and Arthur Chester Woodward, the son of a pharmacist from Roxbury (Massachusetts). In 1918, when Robert was one year old, his father died of an influenza pandemic.
From an early age, Woodward was attracted to chemistry, he enthusiastically self-taught this subject while still studying at the first and second grade school in Quincy , Massachusetts . By the senior classes, he was already able to cope with almost all the experiments described in the well-known Ludwig Guttermann manual for practical classes in organic chemistry. In 1928, Woodward contacted the German Consul General in Boston , and through him he managed to get copies of several new articles published in German journals. Later, in his lecture Koupovskoy, he recalled how he was fascinated when, among these articles, stumbled upon the first report of L. Diels and C. Alder about the reaction they had discovered . Throughout his career, Woodward often used and studied this reaction, both theoretically and experimentally. In 1933, he enrolled at the Massachusetts Institute of Technology (MIT), but so launched some aspects of his studies that he was expelled the following year. In 1935, MIT restored it and by 1936 he received a bachelor 's degree . A year later, the institute awarded him a doctoral degree , while his classmates only graduated from undergraduate degree. Woodward's doctoral work was a study related to the synthesis of the female sex hormone estrone [2] . According to the rules of MIT, it is necessary that graduates have managers. Woodward was led by Avery A. Ashdown, although it is still unknown if he used his advice. After briefly teaching at the University of Illinois, he received a one-year scholarship at Harvard University (1937–1938) and worked at various positions at Harvard for the rest of his life. In 1960, Woodward was awarded the title Donnerovsky professor, this title freed him from teaching compulsory courses, and he was able to devote all his time to scientific research.
Early work
The first major achievement of Woodward in the early 1940s was a series of articles describing the use of ultraviolet spectroscopy in explaining the structure of natural products. Woodward collected a large amount of empirical data and developed a number of rules, later called the "Woodward rules", which could be used to determine the structures of both natural substances and synthesized molecules that are not found in nature. The rational use of the latest instrumental methods was the "calling card" of Woodward's work throughout his career; at the same time, he was constantly moving from monotonous and long-lasting methods for determining the structure to more modern ones.
In 1944 , along with his ward, postdoctoral student William E. von Dering, Woodward reported on the synthesis of the quinine alkaloid used in the treatment of malaria. Although the synthesis was presented as a success, allowing to overcome the difficulties in providing drugs purchased in South Asia , in fact, the synthesis was too long and time consuming to apply it on a practical scale. Nevertheless, it became a turning point for chemical synthesis in general. Woodward's find, important for this synthesis, was the use of the fact of almost 40 years ago, when the German chemist Paul Rabe obtained quinine from his predecessor (precursor) - quinotoxin ( 1905 ). Consequently, the synthesis of quinotoxin (which Woodward actually synthesized) must open the way to the synthesis of quinine. When Woodward realized this, organic synthesis was still in the “trial and error” stage, and no one thought that such complex structures could be created. Woodward showed that organic synthesis can be turned into a rational science and that the development of theoretical knowledge of reactivity and structure could help. This synthesis was the first of a series of extremely complex and elegant syntheses that he did.
Further work and their meaning
In the 1930s, British chemists Christopher Ingold and Robert Robinson began to study the mechanisms of organic reactions and proposed rules of thumb by which it was possible to predict the reactivity of organic molecules . Woodward was apparently the first synthetic chemist to use these ideas to predict structure in synthesis. The example of Woodward inspired hundreds of other synthetic chemists who worked in the field of creating complex structures of natural products that are medically important.
Organic Synthesis and Nobel Prize
During the 1940s, Woodward synthesized many complex natural products such as quinine ( 1944 ), cortisone ( 1951 ), reserpine ( 1956 ), chlorophyll ( 1960 ), tetracycline ( 1962 ), cholesterol , lysergic acid , cephalosporin, and colchicine as well established the structure of a number of important natural compounds: strychnine , terramycin ( oxytetracycline ) (1953) and aureomycin , magnamycin . At the same time, Woodward opened a new era in synthesis (sometimes called the “Woodward era”), in which he showed that natural products can be synthesized only by carefully observing the principles of physical organic chemistry and planning all the steps in detail.
Most of Woodward's syntheses were very impressively described by his colleagues, and before he made them, some thought that it was impossible to create these substances in the laboratory. His syntheses carried an element of art in themselves, and since then, synthetic chemists have paid attention not only to the convenience and practicality of the synthesis, but also to its beauty. The work of Woodward often included the active use of new methods - IR spectroscopy , and later nuclear magnetic resonance (NMR). Another important feature of Woodward's syntheses was that he paid attention to stereochemistry , or a particular configuration of molecules in three-dimensional space. In most cases, natural substances used in medicine possess the necessary biological activity only in the form of pure enantiomers. This led to the demand for "stereospecific synthesis", which resulted in a product with a certain configuration. Today, methods of stereospecific synthesis are widely used; Woodward was the first to show that to carry out such (stereospecific) synthesis, thorough preparation and careful planning are needed. Many of his syntheses were aimed at changing the configuration of molecules by introducing a rigid structural element into them; This technique has become commonplace today. Especially significant in this respect were syntheses of reserpine and strychnine .
During World War II, Woodward was a consultant to the Military Production Council in connection with the penicillin project. Although many suggested the penicillin beta-lactam structure, Oxford chemists and Merck were the first to propose this, and then other groups of scientists were involved in the research (in particular, from Shell). Woodward was the first to suggest that the tricyclic structure was incorrect (thiazolidine was connected by the amino-bridge of oxazinone) put forward by a group of penicillin researchers from Peoria. Subsequently, he agreed with the beta-lactam structure (instead of the thiazolidine-oxazolone), proposed by Robert Robinson, and later - the leading organic chemist of his time. In the end, Dorothy Hodgkin in 1945, using X-ray crystallography, confirmed the beta-lactam structure for penicillin.
To determine the structure of complex molecules, Woodward used infrared spectroscopy and chemical degradation. Here, santoninic acid, strychnine, magnamycin and terramycin are notable examples. Woodward's colleague and Nobel laureate Derek Burton said the following about teramitsin:
The most brilliant structural puzzle solution ever made was, of course, a solution to the problem of terramycin (1953). This was a problem of great industrial importance, and many capable chemists performed an enormous amount of work on determining its structure. The result was an impressive amount of conflicting facts. Woodward took a large piece of cardboard, wrote out all the data on it and, thinking alone, brought out the correct structure of terramycin. No one else could have done that at that time. |
All these cases show how rational facts and chemical principles combined with intuition can be used to achieve a goal.
In the early 1950s, Woodward and the British chemist Jeffrey Wilkinson proposed a new structure of ferrocene - a compound consisting of a combination of organic molecules with iron . This was the beginning of organometallic chemistry , which grew into an industrially significant area. For this work, Wilkinson (along with Ernst Otto Fisher ) received the Nobel Prize in 1973 . Some historians believed that Woodward should have received this award along with Wilkinson. Interestingly, Woodward thought so: he later even wrote about this to the Nobel Committee.
Woodward received the Nobel Prize in 1965 for the synthesis of complex organic molecules. In his Nobel lecture, he described the complete synthesis of the cephalosporin antibiotic, noting that he had to speed up the synthesis in order to have time to finish it before the Nobel ceremony.
Synthesis of vitamin B 12 and the Woodward-Hoffman rules
In the early 1960s, Woodward began the synthesis of a natural product, the most difficult at that time, the synthesis of vitamin B 12 . Cooperating fruitfully with a colleague from Zurich Albert Eschenmozer , Woodward with a team of nearly 100 students and postdocs worked on the synthesis of this molecule for several years. The work was completed and published in 1973; it was a turning point in the history of organic chemistry. The synthesis included almost 100 stages, each of which was carefully planned and analyzed, which was typical of all the works of Woodward. He more than others convinced organic chemists that the synthesis of any complex substance is possible with sufficient time and reasonable planning. However, until 2006, practically no publications on the issue of the complete synthesis of vitamin B 12 were available.
In the same year, based on the observations made by Woodward during the synthesis of B 12 , he and Roald Hoffman developed rules (now known as Woodward-Hoffman rules ) explaining the stereochemistry of products of organic reactions [3] . Woodward formulated his ideas (based on the symmetrical properties of molecular orbitals ), based on his experience as a synthetic chemist, and then asked Hoffman to perform theoretical calculations to confirm these ideas. These calculations were made using the Hückel method . The correctness of these rules has been confirmed by many experiments. Hoffman received the Nobel Prize in 1981 for his work (along with Kenichi Fukui , a Japanese chemist who did the same work using a different approach); Woodward would no doubt receive the second Nobel Prize if he were alive. Note that a recent article in the journal Nature describes how stress can be used to change the course of a chemical reaction whose products do not follow Woodward-Hoffman rules [4] .
Woodward Institute and the last period of life
In parallel with the work at Harvard, Woodward led the Woodward Research Institute, founded in 1963 in Basel ( Switzerland ) [5] . He also became a member of the Board of Trustees of MIT (1966-1971) and the Weizmann Institute of Science in Israel .
Woodward died in Cambridge , Massachusetts from a heart attack during sleep. During this period, he worked on the synthesis of the antibiotic erythromycin . His student said about him:
I owe a great deal to R. B. Woodward. He showed that it is possible to take on solving difficult problems without a clear idea of their outcome, but with confidence that their intellect and efforts will solve them. He showed me the beauty of modern organic chemistry, as well as the importance of a detailed study of the material. Woodward made a significant contribution to the strategy of synthesis, to methods for the derivation of complex structures, to the creation of new chemistry and its theoretical aspects. He was an example for his students. I value the memory of collaboration with such a wonderful chemist. |
Family
In 1938, he married Irje Pullman; they had two daughters: Siri Anna (1939) and Gene Kirsten (1944). In 1946, he entered into a second marriage - with Eudoxia Muller, whom he met at the Polaroid Corporation . She was an artist and engineer. In this marriage were born the daughter of Christel Elizabeth (1947) and the son of Eric Richard Arthur (1953).
Publications
Woodward was the author (or co-author) of nearly 200 publications, of which 85 are great articles, and the rest are preliminary reports, texts of lectures and reviews. The pace of his scientific work did not give the opportunity to publish the details of the experiment, and most of the work was published only several years after his death. Woodward led the work of more than two hundred graduate students and researchers, who later became successful careers. Together with Robert Robinson, he founded the organic chemistry magazines Tetrahedron and Tetrahedron Letters, and was a member of their editorial boards.
Woodward's students include Robert M. Williams ( Colorado ), Harry Wasserman ( Yale ), Yoshito Kishi ( Harvard ), Stuart Schreber (Harvard), William Rusch (Scrips-Florida), ( University of Florida ) , Christopher S. Foote ( University of California, Los Angeles ), Kendall Hawke (University of California, Los Angeles), Kevin M. Smith, working in the field of porphyrins.
Woodward had an encyclopedic knowledge of chemistry and an extraordinary memory for details. The quality that distinguishes him among his colleagues was the remarkable ability to extract and link data from scientific literature and use it to solve this chemical problem.
Character traits, interesting facts
His lectures became a legend, they often lasted for three to four hours. In many of them he avoided the use of slides, and used to paint structures with colored crayons. Therefore, his lectures were easy to record. According to MSU professor A.N. Kosta [6] :
Often in lectures or reports, taking a piece of chalk in both hands, he easily began to draw a chemical structure from both ends of the board, and his spatial vision of the molecule was so subtle that it was not the case that the lines on the board did not converge. |
As a rule, before the lecture, Woodward always put two handkerchiefs on the desktop. On one handkerchief he put a row of 4-5 pieces of chalk of different colors. On the other was an impressive range of cigarettes. The previous cigarette was used to light the next one. His famous seminars on Thursdays at Harvard stretched to the night.
Woodward really liked the blue color. His suit, car and even parking lot were blue. In one of his laboratories, students hung a huge black and white photograph of a teacher with a big blue tie. It hung there for several years (until the early 1970s), until it burned down during a small laboratory fire.
With his indefatigability, Woodward could not have done so much if he had not been an extremely organized person. He solved most of the problems on his own, thinking through a plan of further work to the smallest detail. Every morning, a stooped, strong-built professor in a strict suit with an obligatory blue tie sat in a car and covered the half-mile 50 minutes that separated his cottage from Harvard University . By nine o'clock, after such a high-speed "auto-charge", which he preferred to other sports, Woodward set to work. He could restrict himself to a few hours of sleep at night, was a heavy smoker, preferred whiskey and martini and liked to relax while playing football [7] .
Chemists about Woodward
Derek Barton , who later became famous for his work on conformational analysis (for which he was awarded the Nobel Prize in 1969 ), describes one of Woodward’s lectures this way:
It was a brilliant demonstration of how to take from literature the facts that seem obvious, and by just thinking about them, what he knew how to do, interpret them differently, and then go to the laboratory and prove the truth of the new conclusion. We realized that it was the work of a genius ... Ten years later, our second-year students could solve such problems, and approximately 25% would solve them correctly. But does this mean that in 1958, 25% of mini-Woodworks studied in our second year? Of course not. This means that Woodward taught us, organic chemists, the art of thinking. |
A series of honorary lectures began from Woodward’s 1948 trip, which threw him into many countries throughout his life. Lord Alexander Todd recalled:
One of the most amazing features of Bob Woodward was his ability to infect young chemists with his passion for organic chemistry and his enthusiasm ... I do not know and never knew another scientist who could hold the audience like that; young chemists, and many not very young ones, heeded him like some other evangelist ... Of course, he was a brilliant lecturer. He always fit on time; when it was always his famous box with colored crayons, even a special cloth to wipe off the board. And the fact that he flawlessly drew formulas on the blackboard, although it slowed down the pace of presentation, but contributed to understanding. |
Arne Fredg ( Royal Swedish Academy of Sciences ), when presenting the Nobel Prize, said:
It is sometimes said that organic synthesis is both an exact science and elegant art. Here is the undisputed master - nature. But I dare say that the winner of this year’s award, Dr. Woodward, is rightfully ranked second. |
Awards and rewards
For his work, Woodward received many awards, prizes and honorary degrees, including membership in the National Academy of Sciences of the USA ( 1953 ) and academies around the world. He has also been a consultant to many companies, such as Polaroid , Pfizer and Merck.
Among his awards:
- John Scott Medal from the Franklin Institute and the City of Philadelphia (1945)
- Centenary Award (1951)
- Bakeland Medal from the American Chemical Society in North Jersey (1955)
- Devi Medal from the Royal Society of London (1959)
- Roger Adams Medal from the American Chemical Society (1961)
- Pius XI Gold Medal (1961)
- Weizmann Memorial Lectures (1963)
- (1964)
- National Medal of the United States (1964, "for a new approach to the synthesis of complex organic molecules, especially for the brilliant synthesis of strychnine, reserpine, lysergic acid and chlorophyll")
- Nobel Prize in Chemistry (1965)
- Willard Gibbs Award (1967) from the Chicago Branch of the American Chemical Society (1967)
- Lavoisier Medal from the Chemical Society of France (1968)
- Order of the Rising Sun, Second Class from the Emperor of Japan (1970)
- Ganbury Memorial Medal from the Pharmaceutical Society of Great Britain (1970)
- Pierre Breylanta Medal from the University of Louvain (1970)
- Scientific Achievement Award from the American Medical Association (1971)
- Arthur Cope Prize from the American Chemical Society (1973, jointly with R. Hoffman)
- Copley Medal (1978)
Honorary Degrees
Woodward also received more than 20 honorary degrees, including honorary degrees from the following universities:
- Wesleyan University (1945)
- Harvard University (1957)
- University of Cambridge (1964)
- Brandeis University (1965)
- Israel Institute of Technology in Haifa (1966)
- University of Western Ontario in London ( Ontario , Canada ) (1968)
- Catholic University of Leuven (1970)
Notes
- ↑ Elkan Blout. Robert Burns Woodward // Biographical Memoirs of the National Academy of Sciences. - 2001. - Vol. 80
- Synthetic A synthetic attack on the oestrone problem PhD dissertation (Eng.) . The date of circulation is January 16, 2012. Archived on June 3, 2012.
- ↑ Roald Hoffmann, RB Woodward. Orbital Symmetry Control of Chemical Reactions (eng.) // Science. - 6 February 1970. - Vol. 167, no. 3919 . - P. 825-831. - PMID 17742608 .
- ↑ Biasing Reaction Pathways with Mechanical Force (English) // Nature. - 2007. - Vol. 446. - p. 423-427.
- ↑ G. Wayne Craig. The Woodward Research Institute, Robert Burns Woodward (1917 - 1979) and Chemistry behind the Glass Door // Helvetica Chimica Acta. - 2011. - Vol. 94. - P. 923−946. - DOI : 10.1002 / hlca.201100077 .
- ↑ Robert Burns Woodward . The date of circulation is January 16, 2012. Archived on June 3, 2012.
- ↑ Robert Burns Woodward . The date of circulation is January 16, 2012. Archived on June 3, 2012.
Literature
- Otto Theodor Benfey, Peter JT Morris. Robert Burns Woodward: Architect and Artist in the World of Molecules // Chemical Heritage Foundation. - April 2001.
- Mary E. Bowden. Robert Burns Woodward and the Beatman Center for the History of Chemistry (Publication / Beckman Center for the History of Chemistry) // Chemical Heritage Foundation. - March 1992.
- Alexander Todd , John Cornforth. Robert Burns Woodward. 10 April 1917-8 July 1979 (Eng.) // Biographical Memoirs of the Royal Society : journal. - 1981. - Vol. 27 . - P. 628-695 . - DOI : 10.1098 / rsbm.1981.0025 .
- Woodward RB, Sondheimer F., Taub D. The Total Synthesis of Cortisone (eng.) // Journal of the American Chemical Society : journal. - 1951. - Vol. 73 . - P. 4057-4057 . - DOI : 10.1021 / ja01152a551 .
Links
- Woodward, Robert Burns on the official website of the Russian Academy of Sciences