Chemistry Nobel: Mirror Image Molecules

Chemistry Nobel

Question: Who has won Nobel for Chemistry in 2021?
a) Benjamin list
b) David MacMillan
c) Both a and b
d) None of the above
Ans: c
Recent Context

  • On 6th October 2021 The 2021 Nobel Prize in Chemistry has been awarded to German scientist Benjamin list and Scotland born, US based David W.C. MacMillan “for the development of assymetric organocatalysis”.
    Related Facts
    What is Catalysis?
  • It is a term used to describe a process in the presence of a substance (the catalyst) that controls and influences the rate and/or the outcome of the reaction.
    What is Catalyst?
    When two or more compounds react to form new compounds, the process is often aided by other chemicals called catalyst that do not change themselves, but help speed up the reaction.
    Characteristics of Catalyst
    Remain intact after reaction completion.
    Does not becomes part of the final product.
    Removed so as to not to add impurity to final product.
    Often used to produce new and functional molecules that are utilised in drugs and other everyday substances.
    About the discovery
  • Till around, 2000 only two kinds of catalysts were used – metal & enzymes.
    Metal Catalysts
  • Use heavy metals
    Expensive and environmentally unfriendly.
    Traces remains sometimes in end product making it unsuitable where very pure products are required.
    Highly sensitive to presence of oxygen and moisture, hence industrial application becomes expensive.
  • Enzymes
  • Biological catalyst
    Require water as medium for the chemical reaction, which is not an environment for all kind of chemical reactions.
    Very large size molecules, difficult to use.
  • Asymetric Organocatalysts
  • Both scientist developed this class of catalyst in 2000, which is efficient, precise, cheap, fast and environment friendly.
    Small as made of single amino acids.
    Makes development of new drugs (molecules) easy, cheap and environment friendly.
    About Organocatalysis and Asymmetric Organocatalysis
    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 captrue light in solar cells.
    Asymmetric Organocatalysis
    Substances can have exactly the same chemical composition and molecular formula; yet differ widely in their properties. They are known as isomers.
    One type of isomers are those that differ in the way individual atoms are oriented in three dimensional space. Two molecules could be the same, except that they are mirror images of each 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. 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.
    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.

By Kameshwar Shukla

Reference: https://www.nobelprize.org/prizes/chemistry/