This year’s winners of the Nobel Prize in Chemistry, announced on Wednesday, October 5, discovered catalysts for an elegant new way of creating organic molecules. Their work has opened up the possibility of a wide range of precisely-tuned catalysts for making molecules that were either impossible to make before, or required a long series of synthesis steps.
In 1971, Yves Chauvin, who did his pioneering research at the Institut Francais du Petrole, proposed a mechanism to explain mysterious reactions that chemists at petroleum companies had been observing for decades: although the products, including a precursor to a common plastic, were familiar, the chemistry behind the reactions was unknown.
It took the work of Richard Schrock of MIT (click here to see Schrock), another winner of this year’s prize, to confirm that Chauvin was right. Schrock made metal-carbon catalysts that took apart molecules with strong double bonds and reassembled them.
Because of his work, chemists now know not only how these catalysts work, but also that they can be tuned to create different products by altering the arrangement of atoms around the catalyst’s core. Because so many combinations of metals and surrounding atoms are possible, Schrock’s work has opened up a vista of possibilities for chemists.
”It was very exciting,” says Guillermo Bazan, a graduate student in Schrock’s lab in 1990, who first saw the evidence that they had the catalyst they needed. Bazan, now a professor of organic chemistry at the University of California at Santa Barbara, sat staring in amazement for 20 minutes at the peak showing the MIT researchers were successful. He had finished a long project, but remembers thinking: “ ‘Where do we begin?’ Because we had so many things we could do.”
The catalyst, which used the metal molybdenum, was described in a 1990 paper. Two years later, another chemist, Robert Grubbs, at Caltech, the third winner of the prize, created a catalyst using ruthenium. Although not as active as Schrock’s, Grubbs’ version could be used under everyday conditions. The convenience of Grubb’s catalysts have led to widespread use.
The catalysts resulting from their research have become “dominant” in many areas of chemistry, says Amir Hoveyda, a professor of chemistry Boston College. Yet Hoveyda says the applications of the technology “are not even 5 to 10 percent realized.”
Still, numerous valuable compounds, including potential drugs for hepatitis C, fungal infections, influenza, and AIDS, are directly traceable to the work of this year’s three chemistry Nobelists. Indeed, at least two drugs using these kinds of catalysts are now in late-stage human trials.
The reactions made possible with the catalysts can also be used to make advanced plastics, such as electrically conductive polymers.
For many reactions, the catalysts produced by Schrock and Grubbs led to far more efficient synthetic processes. “They’re the cleanest reactions you could deal with,” says Sarah Dolman, a recent graduate from the Schrock group, who now works at Merck Frosst, a pharmaceutical company based in Kirkland, Canada .
Although these catalysts have proved their practical value, and promise many more applications, Schrock points out that these advances all came as a result of the scientists being allowed to indulge their own curiosity. “These initial discoveries were the result of basic research, I didn’t know where it was going to go,” Schrock said.