The 2026 Nobel Prize in Chemistry was awarded to French chemist Henri B. Kagan and Japanese scientist Kenzo Soai. On October 7, the Royal Swedish Academy of Sciences recognized them for the discovery of nonlinear effects and autocatalysis in asymmetric organic synthesis, reports UNN.
Details
Their research helped explain one of chemistry’s longstanding mysteries: how, in a system where molecules can exist in two mirror-image forms, one of them can gain an advantage and eventually almost completely displace the other.
What the Nobel Prize was awarded for
To understand the essence of the discovery, it is enough to imagine the right and left hands. They are similar, but it is impossible to place one over the other so that all their parts coincide. Chiral molecules behave in the same way: they can have two forms, or enantiomers, that are mirror images of each other. In ordinary chemical synthesis, approximately equal amounts of both forms are often produced. In living nature, the situation is different. Proteins, for example, are composed predominantly of amino acids of one “handedness.” This preference for one mirror-image variant is called homochirality. Chemists spent decades trying to understand why nature was able to make this choice and how such a process could be replicated in the laboratory.
In 1986, Henri Kagan showed that in asymmetric reactions, the relationship between the composition of the catalyst and the composition of the product is not necessarily direct. A slight advantage for one mirror-image variant of a catalyst can sometimes produce a disproportionately large advantage for the same variant of the product. This phenomenon became known as the nonlinear effect.
Kenzo Soai went further. In 1995, his team described an asymmetric autocatalytic reaction in which the product itself accelerates the formation of new molecules of the same type. If even a small excess of one enantiomer exists at the outset, the reaction can amplify it. In 2003, Soai demonstrated a system in which an almost complete predominance of one of two mirror-image forms could emerge from an achiral initial environment.
Why this discovery is important
Chirality is directly relevant to pharmaceuticals. Biological molecules are also spatially selective, so two enantiomers of the same substance can interact differently with enzymes and receptors. One variant may produce the desired therapeutic effect, while the other may be less active, inactive, or cause a different effect.
That is why it is important for chemists to control which spatial form they obtain. Asymmetric synthesis helps create the desired compounds more precisely and reduce the proportion of unwanted products.
Kagan’s work became one of the foundations of modern asymmetric catalysis, which is important for synthesizing complex organic molecules, including pharmaceutical compounds. Soai’s reaction is primarily of fundamental importance: it became a model for how a tiny initial asymmetry can amplify itself. This is also important for research into the origin of homochirality and the chemical prerequisites for the emergence of life.
What the Nobel Committee said
The Royal Swedish Academy of Sciences emphasized that the work of Kagan and Soai provided an answer to a chemical mystery that is more than a century old.
Henri Kagan and Kenzo Soai have given us a solution to a chemical mystery that is more than 100 years old: how homochirality can arise spontaneously. The chemical reactions they developed are impressive
The committee emphasized that the laureates’ discoveries revealed the mechanisms by which a small initial imbalance between two mirror-image forms of molecules can be sharply amplified.
What is known about the laureates
Henri B. Kagan was born in 1930 in Boulogne-Billancourt, France. He earned his doctoral degree in 1960 at the Collège de France. He is an emeritus professor of the former University of Paris-Sud and has studied asymmetric synthesis and catalysis for many decades. In 2001, Kagan, together with Ryoji Noyori and Barry Sharpless, received the Wolf Prize in Chemistry for pioneering work in asymmetric catalysis.
Kenso Soai was born in Hiroshima in 1950. He received his doctoral degree from the University of Tokyo in 1979 and later worked at the Tokyo University of Science, where he is now an emeritus professor. The Soai reaction, one of the best-known examples of asymmetric autocatalysis, is named after him. In 2023, he received the Ryoji Noyori Prize for research into chirality.
How the scientists made their discovery
The 2026 Nobel Prize brought together research that developed over nearly four decades. In 1986, Kagan described nonlinear effects in asymmetric catalysis and showed that a small advantage for one variant of a catalyst could produce a much greater predominance of the corresponding form of the product.
In 1995, Soai and his colleagues published a paper in Nature on asymmetric autocatalysis. They demonstrated that the reaction product could catalyze its own formation while simultaneously amplifying the initial enantiomeric imbalance. Subsequent experiments proved that such a process could drive the system toward the near-total dominance of one mirror-image form.
About 40 years passed between Kagan’s first key paper and the Nobel Prize, while more than 30 years passed since Soai’s landmark publication.
What the laureates will receive
The total prize money for the 2026 Nobel Prize in Chemistry is 12 million Swedish kronor. Kagan and Soai will split the sum equally—6 million kronor each. In addition to the monetary award, each laureate will receive a Nobel medal and a personal diploma. The award ceremony will take place on December 10 in Stockholm—on the anniversary of Alfred Nobel’s death.
Who received the 2025 Nobel Prize in Chemistry
Last year, the Chemistry Prize was awarded to Susumu Kitagawa, Richard Robson, and Omar M. Yaghi for the development of metal–organic frameworks. These are porous molecular structures with internal cavities that can be used to absorb carbon dioxide, collect water from dry air, store gases, and catalyze chemical reactions.
What is known about the Nobel Prize in Chemistry
The Nobel Prize in Chemistry has been awarded since 1901, in accordance with the will of Swedish inventor and industrialist Alfred Nobel. Laureates are selected by the Royal Swedish Academy of Sciences on the recommendation of the Nobel Committee for Chemistry.
Before the announcement of the 2026 prize, the Chemistry Prize had been awarded 117 times to 200 laureates. Following this year’s decision, the figures are now 118 prizes and 202 laureate awards. The number of individual people is lower because Frederick Sanger and Barry Sharpless each received the Nobel Prize in Chemistry twice.
It is not possible to nominate oneself for the prize. Candidates are proposed by scientists and institutions that have the relevant authority or receive an invitation from the Nobel Committee. Information about the nominees, those who nominated them, and the materials from the deliberations remains confidential for 50 years.