Nobel Prize for Chemistry, 2021

• 07 Oct 2021

Why in News

The 2021 Nobel Prize in Chemistry was awarded to Benjamin List and David MacMillan for the development of asymmetric organocatalysis.

• Last year, the honour went to Frenchwoman Emmanuelle Charpentier and American Jennifer Doudna, for developing the gene-editing technique known as CRISPR-Cas9 - DNA snipping "scissors".
• Nobel prizes in physics and medicine for 2021 have already been announced.

Key Points

• About the Development:
  
  • They have developed a new and ingenious tool for molecule building: organocatalysis.
    
    • Many research areas and industries are dependent on chemists’ ability to construct molecules that can form elastic and durable materials, store energy in batteries or inhibit the progression of diseases. This work requires catalysts.
    • According to researchers, there were just two types of catalysts available: metals and enzymes. Catalysts are any substance that increases the rate of a reaction without itself being consumed.
  • In 2000, they, independent of each other, developed a third type of catalysis. It is called asymmetric organocatalysis and builds upon small organic molecules.
• Significance:
  
  • Its uses include research into new pharmaceuticals and it has also helped make chemistry greener.
  • Both these sets of catalysts (metals and enzymes) had limitations.
  • Heavier metals are expensive, difficult to mine, and toxic to humans and the environment.
    
    • Despite the best processes, traces remained in the end product; this posed problems in situations where compounds of very high purity were required, like in the manufacture of medicines.
    • Also, metals required an environment free of water and oxygen, which was difficult to ensure on an industrial scale.
  • Enzymes on the other hand, work best when water is used as a medium for the chemical reaction. But that is not an environment suitable for all kinds of chemical reactions.
• Organocatalysis:
  
  • Organic compounds are mostly naturally-occurring substances, built around a framework of carbon atoms and usually containing hydrogen, oxygen, nitrogen, sulphur, or phosphorus.
  • Life-supporting chemicals like proteins, which are long chains of amino acids (carbon compounds containing nitrogen and oxygen) are organic.
  • Enzymes are also proteins, and therefore, organic compounds. These are responsible for many essential biochemical reactions.
  • Organocatalysts allow several steps in a production process to be performed in an unbroken sequence, considerably reducing waste in chemical manufacturing.
  • Organocatalysis has developed at an astounding speed since 2000. Benjamin List and David MacMillan remain leaders in the field, and have shown that organic catalysts can be used to drive multitudes of chemical reactions.
    
    • Using these reactions, researchers can now more efficiently construct anything from new pharmaceuticals to molecules that can capture light in solar cells.
• Asymmetric Organocatalysis:
  
  • The process called asymmetric organocatalysis, has made it much easier to produce asymmetric molecules - chemicals that exist in two versions, where one is a mirror image of the other.
  • Chemists often just want one of these mirror images - particularly when producing medicines - but it has been difficult to find efficient methods for doing this.
  • Some molecules with mirror versions have different properties. An example is the chemical called carvone, which has one form that smells like spearmint and a counterpart that smells like the herb, dill.
  • Different versions of the same molecule might have different effects when ingested. Then it becomes important to be able to make only the mirror image of a drug that has the desired physiological effect.

Source: IE