Nobel chemistry award has pleasing symmetry
This year's Nobel Prize in Chemistry has been awarded to three researchers who developed the technique of catalytic asymmetric synthesis, which allows chemists to steer reactions towards one of two possible symmetrical products.
Half of the prize goes to K. Barry Sharpless of the Scripps Research Institute in La Jolla, California, for his work on oxidation reactions. The other half is shared by two researchers for their work on hydrogenation reactions: Ryoji Noyori of Nagoya University, Japan, and William Knowles, a retired chemist who worked at biotechnology company Monsanto in St Louis, Missouri until 1986.
The winners studied reactions that, under normal circumstances, produce an equal mixture of two products with symmetrical structures. Known as chiral products, these molecules are mirror images of each other, but can have very different properties. The side-effects of the morning-sickness drug thalidomide, for example, were caused by a rogue chiral twin of the molecule that the drug's designers had intended to use.
Sharpless, Noyori and Knowles have been awarded the prize for developing techniques that tailor reactions so that only one of the two chiral molecules is produced. The techniques are now widely used in industry, particularly to manufacture pure pharmaceuticals.
In 1968 Knowles discovered that, by using a chiral catalyst, he could tweak a hydrogenation reaction, in which hydrogen is added to organic molecules, so that it produced 15% more of one chiral product. His team went on to develop a method for industrial synthesis of the amino acid L-DOPA, a chiral molecule that is used to treat Parkinson's disease.
Knowles' work was extended by Noyori, who developed further catalysts, some of which can hydrogenate many types of molecule. Reactions using his catalysts give very pure products and high yields, and are now widely used to manufacture large quantities of antibiotics.
“Their contributions have had fundamental impacts from agribusiness to pharmaceuticals Steven Ley, president of Britain's Royal Society of Chemistry ”
Sharpless developed chiral catalysts for oxidation reactions during the 1980s. One of these, which allows the asymmetric oxidation of a class of alcohols, is seen by many chemists as one of the most important discoveries made in the field of synthesis during the past few decades. One product, glycidol, is now used in the production of beta-blockers.
"The work of Sharpless and Noyori have changed the way we think about chemical synthesis," says Steven Ley, a chemist at the University of Cambridge and president of Britain's Royal Society of Chemistry. "Their contributions have had fundamental impacts on an industrial scale from agribusiness to pharmaceuticals."
However, Ley said he was surprised that Henri Kagan, a chemist at Universite Paris-Sud who also worked on asymmetric synthesis, had been overlooked. Together with Sharpless and Noyori, Kagan won this year's Wolf Foundation Prize in chemistry, which is seen by many as an indicator of future Nobel success.