Henri Kagan and Kenso Soai Win 2026 Nobel Prize in Chemistry for Research on Molecular Chirality

French chemist Henri B. Kagan and Japanese chemist Kenso Soai have won the 2026 Nobel Prize in Chemistry for discoveries that helped explain how chemical reactions can favor one of two mirror-image forms of a molecule.

Henri Kagan of France and Kenso Soai of Japan have received the 2026 Nobel Prize in Chemistry for discoveries involving asymmetric organic synthesis and autocatalysis. [Illustration: Niklas Elmehed, The Nobel Prize]

Many molecules exist in two forms that are mirror images of one another, much like a person’s left and right hands.

This property is known as chirality. It is especially important in biology because many molecules essential to life, including amino acids and sugars, have specific molecular orientations.

How such asymmetry emerged has long been a question for scientists.

Ordinary chemical reactions often produce both mirror-image forms, but certain processes can favor one form over the other.

The Royal Swedish Academy of Sciences awarded the 2026 chemistry prize to Kagan and Soai for discoveries involving nonlinear effects and autocatalysis in asymmetric organic synthesis.

Kagan’s work helped establish important methods for asymmetric synthesis, in which chemical reactions are directed toward producing a desired molecular form.

Soai’s research demonstrated how an asymmetric reaction can amplify a small initial imbalance through autocatalysis, in which a reaction product helps promote the same reaction.

These discoveries are important in pharmaceutical chemistry because two mirror-image forms of a molecule can interact differently with the human body.

Producing the desired form can therefore be crucial to a medicine’s effectiveness and safety.

Chemists have long used chiral catalysts and other methods to selectively produce one molecular form.

The Nobel-recognized research advanced understanding of how asymmetry can emerge and be amplified during chemical reactions, offering insights relevant to the broader question of how biological systems came to favor particular molecular orientations.

The prize recognizes fundamental discoveries in chemistry as well as methods that have influenced the development of chemical synthesis, including processes used in pharmaceutical research.