Benjamin List and David MacMillan Niklas Elmehed/ Nobel Prize Outreach
Benjamin List and David MacMillan have been awarded the 2021 Nobel Prize in Chemistry for their innovative catalyst that allows chemical reactions to take place and allows chemists control how handed their molecules are.
This toolbox is widely used today, such as in drug discovery. It has already greatly benefited humanity, stated Pernilla Wittung–Stafshede (a member of Nobel committee) during the prize announcement.
Wittung-Stafshede said that up until 2000 we knew only two types of catalysts to make chemical reactions happen. The first is enzymes. These large molecules are made up of thousands or hundreds of amino acids. Another type is metal catalysts such as platinum in catalytic convertors. The metal is often embedded in a molecule.
List is now working at the Max Planck Institute for Coal Research, Germany. He wondered if an enzyme was actually needed to catalyze one reaction. Instead, he tried using proline as an amino acid.
List said that I was skeptical about this experiment. It worked and I felt that this could be a big deal.
Princeton University's David MacMillan was using a metal catalyst in the form a small molecule with a copper atom. This molecule was unstable. MacMillan then tried simple organic molecules, which contain carbon but do not contain any metal atoms. He discovered one that worked.
List and MacMillan's work demonstrated for the first time that small organic molecules could act as catalysts. These small organic catalysts can produce molecules with a particular handedness. Many molecules can be made with mirror images of the left- or right-handed side by side, which can give them different properties. This is why the field is called asymmetric organocatalysis.
Wittung-Stafshede said that small organic molecules can do the same job of big enzymes or metal catalysts. These reactions are precise, inexpensive, fast, and environmentally friendly. Their findings opened up a new way to think about how to make organic molecules.
List claims that the potential of this new type of catalyst is starting to be realized. He said that the early catalysts were perhaps a million times less efficient than today's. These highly reactive organic catalysts are the real breakthrough in our research. They can do things that enzymes and even sophisticated metal complexes cannot.