The 2021 Nobel Prize in Chemistry was awarded to Benjamin List and David MacMillan for their pivotal role in developing asymmetric organocatalysis. The same honor went to Emmanuelle Charpentier and Jennifer Doudna from France and America, respectively, in the previous year for their advancements in the CRISPR-Cas9 gene-editing technique, considered the “scissors” of DNA. Meanwhile, Nobel prizes for physics and medicine have already been announced for this year.
About the Development
List and MacMillan have ingeniously developed a new tool called organocatalysis for building molecules. Chemists heavily rely on this tool in various research areas and industries to create molecules that can form durable and elastic materials, store energy in batteries, or prevent disease progression.
Traditionally, chemists had only two types of catalysts: metals and enzymes. Catalysts work by speeding up a reaction rate without undergoing any change themselves. However, List and MacMillan independently created a third type of catalyst in 2000, known as asymmetric organocatalysis, which builds upon small organic molecules.
The Significance of Organocatalysis
Organocatalysis has unlocked new opportunities in pharmaceutical research and made chemistry more eco-friendly. The previous catalysts, metals, and enzymes, were fraught with limitations. For instance, heavier metals are not only costly, hard to mine, but also toxic to humans and the environment. Despite utilizing the best practices to taper down their presence, traces of these metals inevitably remained in the final product, posing potential risks especially in situations where high purity compounds were needed, such as in pharmaceutical manufacturing. Additionally, working with such metals required an oxygen and water-free environment difficult to maintain at an industrial scale.
Enzymes, while beneficial when water served as a reaction medium, fall short in facilitating all types of chemical reactions.
Understanding Organocatalysis
Organic compounds, the primary ingredients in organocatalysts, are generally naturally-occurring substances built around carbon atoms and often contain other elements like hydrogen, oxygen, nitrogen, sulfur, or phosphorus. Essential life-sustaining chemicals such as proteins, which are long chains of organic compounds, and enzymes are likewise considered organic compounds.
Organocatalysts offer efficiency by allowing several steps in a production process to be performed sequentially, significantly reducing waste in chemical manufacturing. Since its inception in 2000, organocatalysis has seen immense growth with Benjamin List and David MacMillan continuing to lead the field. They have demonstrated that organic catalysts can play a role in driving numerous chemical reactions, enabling researchers to construct everything from new pharmaceuticals to molecules capable of capturing light in solar cells more effectively.
Asymmetric Organocatalysis Explored
The development of asymmetric organocatalysis has simplified the production of asymmetric molecules – chemicals that exist in two mirror-image versions. Chemists often need just one of these versions, especially when manufacturing medicines. However, it was challenging to find efficient methods for this. Some molecules with mirrored versions exhibit different properties, as is the case with carvone. One form of carvone smells like spearmint while the other resembles the herb, dill. Given that different versions of the same molecule may trigger different effects when ingested, it becomes crucial to produce only the mirror image of a drug that yields the desired physiological effect. This requirement underscores the importance of asymmetric organocatalysis in chemistry.