2021 Nobel Prize in Chemistry

Eva Higginbotham reports on the 2021 Nobel Prize in Chemistry winners...

Eva - Next up on the roster was the Nobel prize for chemistry, and this year it was awarded for a process called asymmetric organocatalysis.

This allows chemists much greater control over the molecules they produce. You see, some molecules exist in two forms, They are almost identical except reversed, just like our hands, it would appear that they are mirror images of each other.

Interestingly, these mirror-image (or chiral) molecules can behave in different ways. Let's take limonene as an example, this hydrocarbon is found in the peel of citrus fruits. It is commonly used for pharmaceuticals and for flavouring in the food industry. One form of the limonene molecule our noses detect as having a lemon scent, while the mirror image smells like orange.

As well as having different properties these mirror image molecules can also react differently in our bodies and so it is important to be able to produce only the desired form, especially for pharmaceuticals.

Benjamin List and Briton MacMillan were responsible for developing the technique of asymmetric organocatalysis back in 2000, a tool that makes it much easier to select the form of molecule desired.

The duo independently developed a brand new form of catalyst. A catalyst is something this is not used up in a chemical reaction but can make the reaction faster, cheaper, greener and in this case help select the desired molecule. Until 2000 it was generally assumed that, in principle there were only two types: metals and enzymes. These new organic catalysts are based upon a stable network of carbon atoms, and are environmentally friendly and cheap to make.

21 years later, the award committee deemed their findings practical implications, which range from pharmaceuticals to solar cells, worthy of a Nobel Prize.