Henri B. Kagan and Kenso Soai have been awarded the 2026 Nobel Prize in Chemistry for their discovery of “non-linear effects and autocatalysis in asymmetric organic synthesis,” the Royal Swedish Academy of Sciences announced in Stockholm on Wednesday.
Their groundbreaking work helped explain how chemical reactions can favour one of two mirror-image forms of a molecule, a phenomenon known as chirality. The discovery has major implications for the development of pharmaceuticals, flavours, fragrances and new materials.
Henri Kagan, a French chemist, discovered a new way of manipulating chemical reactions that allowed a small imbalance between molecular mirror images to be amplified, producing a much greater excess of one form than previously thought possible. His work laid the foundation for understanding how chemical asymmetry can develop and be controlled.
Japanese chemist Kenso Soai took the work further with what became known as the Soai reaction. He developed a chemical reaction in which the product itself acts as a catalyst, allowing one molecular form to reinforce its own formation. The reaction became a landmark example of autocatalysis and demonstrated how chemical handedness could be dramatically amplified.
“Henri and Kenso have provided a solution to a chemical mystery that is over a century old: how homochirality can emerge spontaneously,” Heiner Linke, chair of the Nobel Committee for Chemistry, said.
Homochirality refers to the phenomenon in which living systems predominantly use just one of two possible mirror-image forms of certain molecules. For example, amino acids found in proteins occur predominantly in one molecular orientation. The work of Kagan and Soai has offered important insights into how such molecular asymmetry might arise.
Henry Kagan, 95, is affiliated with Université Paris-Sud in Orsay, France, while Kenso Soai is affiliated with the Tokyo University of Science in Japan. They will share the 2026 Nobel Prize in Chemistry and the accompanying prize money of 12 million Swedish kronor.