Noyori, Nobel prize

A different approach to making chiral drugs is asymmetric synthesis. An optically inactive precursor is converted to the drug by a reaction that uses a special catalyst, usually an enzyme (Chapter 11). If all goes well, the product is a single enantiomer with the desired physiological effect In 2001, William S. Knowles, Ryogi Noyori, and K. Barry Sharpless won the Nobel Prize in chemistry for work in this area. 

The standard work of Evans [2] as well as a survey of the papers produced in the Journal of Labeled Compounds and Radiopharmaceuticals over the last 20 years shows that the main tritiation routes are as given in Tab. 13.1. One can immediately see that unlike most 14C-labeling routes they consist of one step and frequently involve a catalyst, which can be either homogeneous or heterogeneous. One should therefore be able to exploit the tremendous developments that have been made in catalysis in recent years to benefit tritiation procedures. Chirally catalyzed hydrogenation reactions (Knowles and Noyori were recently awarded the Nobel prize for chemistry for their work in this area, sharing it with Sharpless for his work on the equivalent oxidation reactions) immediately come to mind. Already optically active compounds such as tritiated 1-alanine, 1-tyrosine, 1-dopa, etc. have been prepared in this way. 

For a related complex, see W. V. Konze, B. L. Scott, and G. J. Kubas, J. Am. Chem. Soc. 124 (2002), 12 550 Bill Knowles shared the 2001 Nobel Prize (with Barry Sharpless and Ryoji Noyori) for his development of catalytic asymmetric hydrogenation. 

The asymmetric hydrogenation of cinnamic acid derivatives has been developed by Knowles at Monsanto [4], The synthesis of L-dopa (Figure 4.3), a drug for the treatment of Parkinson s disease, has been developed and is applied on an industrial scale. Knowles received the Nobel Prize for Chemistry in 2001 together with Noyori (see below, BINAP ) and Sharpless (asymmetric epoxidation). 

I. Noyori, R. Ohta, M. Hsiao, Y. Kitamura, Ma. Ohta, T. Takaya, H. J. Am. Chem. Soc. 1986, 108, 7117. Ryoji Noyori (Japan, 1938—) and Herbert William S. Knowles (USA, 1917—) shared half of the Nobel Prize in Chemistry in 2001 for their work on chirally catalyzed hydrogenation reactions. K. Barry Sharpless (USA, 1941—) shared the other half for his work on chirally catalyzed oxidation reactions. 

One of the success stories of transition metal catalysis is the rhodium-complex-catalyzed hydrogenation reaction. Asymmetric hydrogenation with a rhodium catalyst has been commercialized for the production of L-Dopa, and in 2001 the inventor, Knowles, together with Noyori and Sharpless, was awarded the Nobel Prize in chemistry. After the initial invention, (enantioselective) hydrogenation has been subject to intensive investigations (27). In general, hydrogenation reactions proceed... 

One of the earliest examples of such catalysis was demonstrated in 1966 by the Japanese chemist Hitosi Nozaki, who reacted styrene and ethyl diazoacetate in the presence of a chiral Schiffbase-Cu11 complex [72-74], Although the initial enantios-electivity was modest (<10% ee), the principle was proven. Some years later, the companies Sumitomo and Merck used similar copper catalysts for asymmetric cyclopropanation on a multikilogram scale, in the production of various insecticides and antibiotics [75]. One of Nozaki s PhD students at that time was Rioji Noyori, who later developed the BINAP asymmetric hydrogenation catalysts for which he received the 2001 Nobel Prize in Chemistry [7[. 

Asymmetric catalysis allows chemicals to be manufactured in their enantiomer-ically pure form and reduces derivatisation and multiple purification steps that would otherwise be required. The 2001 Nobel Prize was awarded for two of the most important asymmetric reactions hydrogenations and oxidations. A variety of ligands suitable for asymmetric reductions are available commercially including BINAP, Figure 3.16. A BINAP Rh complex is used in the commercial production of 1-menthol to enantioselectively hydrogenate an alkene bond (Lancaster, 2002). Ru BINAP complexes can be used in asymmetric reductions of carbonyl groups (Noyori, 2005 Noyori and Hashiguchi, 1997). 

In 2001, Knowles and Noyori s pioneering achievements in this field were honored with the award of the Nobel Prize in Chemistry. 

The 2001 Nobel Prize in chemistry was shared by W. S. Knowles, who developed these chiral hydrogenations at Monsanto R. Noyori, who also worked in the area of chiral hydrogenations and K. B. Sharpless, who developed methods for chiral epoxi-dation reactions. 

In the light of the above set of examples, it is obvious why it is so important to produce chirally pure substances [68], Three scientists from among those who worked out reliable and efficient techniques for this purpose were awarded the Nobel Prize for Chemistry in 2001, K. Barry Sharpless, William S. Knowles, and Ryoji Noyori. The Swedish academician who introduced the three scientists at the award ceremony stressed that they have developed chiral catalysts in order to produce only one of the [chiral] forms [69], Chiral production and separation continue to be among the most practical problems in the application of chemical advances [70],... 

In the intervening four years since the appearance of Volume 22, there has both joy and sadness on the advisory board. In a wonderful recognition of the importance of stereochemistry in synthesis and catalysis, the Nobel Foundation Awarded the 2001 Nobel Prize in Chemistry to two of our board members, Ryoji Noyori and K. Barry Sharpless (along with William S. Knowles). Congratulations ... 

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