Knowles, William( Chemist, Nobel Prize in Chemistry 2001)
Comments for Knowles, William
Biography Knowles, William
Knowles, William (Knowles, William) (p. 1917) (USA). Nobel Prize in Chemistry 2001 (with R. Noiori and K. B. Sharpless).
Born June 1, 1917 to Mr.. Taunton, Mass., and grew up near New Bedford. His parents, who had a craving for business and medicine, gave him a good education. He attended school in Berkshire, and prospered in mathematics and science.
After school, went to Harvard University. In the summer, managed to swim on a sailing schooner to Stockholm.
At Harvard, took up chemistry with a strong mathematical bias. In 1939 the University has been completed, and Knowles began working at Columbia University in the famous organic chemist R. Elderfilda, conducting studies with cardiac glycosides. Simultaneously, he, along with the working out of the anti-malarial drugs, needed army.
In 1942, Knowles moved to Dayton, Ohio, and began work on the synthesis of explosives in the laboratory of the company 'Monsanto'. In 1944 he moved to another lab company in St. Louis, to deal with plasticizers and intermediates. At the same time for military purposes had to handle repellents soldier's clothing, as well as deal with DDT. At the same time, Knowles has been involved in the production of the antibiotic chloramphenicol.
He worked with cortisone, but because he was sent by 'Monsanto' to RB Woodward (Nobel Laureate, 1965) in Cambridge, to join in the total synthesis of this steroid.
In 1950, Knowles worked kinetic studies aimed at improving the production processes of some firms, then he turned to the asymmetric hydrogenation reaction, which later brought him fame.
As a result, laboratory or industrial synthesis of molecules nehiralnyh usually a mixture of enantiomers. The term 'chirality' as the asymmetry of the molecule previously introduced earlier in the constant everyday life Nobel Prize winner Vladimir Prelog. For one of the enantiomers, ie. for chiral synthesis, chiral effects required. Thus, for hydrogenation nehiralnoy molecules in a single enantiomer of a chiral catalyst required for hydrogenation reactions.
We had to develop a common methodology directed chiral synthesis, first and foremost, it is to be implemented for the most common organic reactions - reduction and oxidation
. The first chiral catalyst in the reduction reaction - namely, hydrogenation, was developed by Knowles in 1968 for the synthesis of drugs 'levodopa', used in the treatment of Parkinson's disease during his work in pharmaceutical companies 'Monsanto'
. Synthesis of this drug, which is the amino acid, the reaction is carried out by hydrogenation in the presence of a catalyst - ions of rhodium. Jonah, of course, nehiralny, but they form complexes. If you make a complex with an enantiomer of a chiral ligand, then the catalyst is a chiral. Knowles suggested as a ligand enantiomer of a chiral molecule organophosphorus compounds - Dipamp'a and as a result of successfully solved the problem of industrial production 'levodopa'
. Chiral catalysis of hydrogenation reactions made possible the synthesis of enantiomers of chiral molecules is very simple, which can be used as building blocks - synthons for the preparation of complex chiral structures of natural origin
. Methods of stereoselective hydrogenation has made available many terpenes, vitamins, amino acids, antibiotics, alkaloids, prostaglandins and other biologically important compounds, and a number of them began to produce industrial. That such a scheme was used, for example, for the synthesis of the antibiotic levoflaksina, where he was employed one of the optical isomers of 1,2-propanediol
. In 2001, Knowles, together with R. Noiori was awarded half the Nobel Prize 'for their work on chirally catalysed hydrogenation reactions'
. The other half received the B. K. Sharpless.
Nobel Prize in chemistry in 2001 illustrates that the path from basic studies to their technical implementation may be extremely short.
Especially prominent role of these discoveries in the industry - in the production of new drugs, pheromones, pesticides, food additives, vitamins, chiral synthons, etc..
Discovery of Nobel laureates in 2001 inspired the search for new schemes of catalytic asymmetric synthesis, the feasible set of research groups around the world. These findings make a significant contribution not only in chemistry, but also in material science, biology and medicine, opening the way for new molecules - carriers are unexplained and unexpected properties of the molecular world.
Knowles is proud to have preferred to do all the experiments with their own hands. He worked until 1986, when retired. He and his family bought a small house in Jackson Hole, Wyoming, where the fishes, is keen on foot and bicycle trips.