The 2026 Nobel Prize in Chemistry was shared by Henri B. Kagan of France and Kenso Soai of Japan. The prize honours their work on how chiral molecules, which exist in mirror-image forms, can be produced in one form and how a small imbalance between those forms can be amplified. The Royal Swedish Academy of Sciences announced the award on October 7, 2026.
Award and citation
The prize was given "for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis". The Academy's announcement was made by its Secretary General, Ellen Moons, and the Nobel Committee's chair, Heiner Linke, described the work as a major step for chemists. The prize amount is 12 million Swedish kronor, shared equally between the laureates. Since the first chemistry prize in 1901, 118 chemistry prizes have been given to 200 laureates, which places this award in a long series of recognitions for chemistry within the Nobel Prize system.
Laureates
Kagan was born in 1930 in Boulogne-Billancourt, France, and earned his PhD in 1960 from the Collège de France. He later became Professor Emeritus at the then Université Paris-Sud. At the time of the announcement he was 95 years old, making him one of the oldest science laureates. Soai was born in 1950 in Hiroshima, Japan, received his PhD in 1979 from the University of Tokyo, and is Professor Emeritus at Tokyo University of Science. Sources differ on Kagan's current affiliation: one describes the institution as Paris-Saclay University, which is the successor of the Université Paris-Sud.
Scientific background
Chirality and homochirality
Molecules that are chiral are those whose mirror images cannot be superimposed on each other. This property is known as chirality, or handedness, because human hands are also mirror images. Many components of living systems depend on this property: some molecules, such as amino acids, exist as two variants that are each other's mirror image, yet living organisms contain only one of these mirror images. Sugars, proteins and DNA are built from chiral building blocks. The preference of life for a single form is called homochirality, and how this chemical asymmetry could have emerged was long a mystery to chemists.
Laboratory synthesis has traditionally been the difficulty. Normally when chemists produce chiral molecules in the lab, they get equal amounts of both forms. The awarded work addressed this by showing that the balance could be shifted deliberately, and in some cases that the balance could amplify itself. Producing one mirror image is important for stereochemical control of molecules in general, and in particular for enantiomers with different biological effects.
Non-linear effects (Kagan)
Kagan's contribution concerns asymmetric catalysis. His analysis showed that the enantiomeric excess of the product can exceed that of the auxiliary used in the process, a situation that was previously unthinkable. Kagan was able to demonstrate that using specific catalysts could lead to producing one form of handedness more than the other. The work was carried out in the 1980s; Kagan's prize-winning work dates back to 1986.
Autocatalysis and the Soai reaction (Soai)
Autocatalysis means that a reaction product speeds up its own formation. Asymmetric autocatalysis refers to reactions in which the final product molecule helps to bias the formation of one enantiomer over the other. In the reaction now known as the Soai reaction, a dialkylzinc reagent is added to an aldehyde, and the product acts as the catalyst in the process. Four years after Kagan's work, Soai and his team reported an autocatalytic reaction involving the addition of dialkylzinc reagents to pyridine-3-carbaldehyde. The product was a chiral species that could catalyse its own formation, but the enantiomeric excess of the final products was lower than that of the initial catalyst. Soai's later experiments were more effective. In 2003 Soai succeeded in producing the chiral alcohol with the same configuration as the catalyst. Using autocatalysis, one of the mirror images can be created "from nothing," as Peter Somfai put it. Somfai, a member of the Nobel Committee, has called the reaction "probably the coolest experiment in organic chemistry".
Significance
The committee said that the discoveries by Kagan and Soai have reshaped our understanding of molecular chirality, how it is created, amplified and transmitted. Their practical value lies in chemical manufacturing. Their discoveries have been decisive for chemists who design reactions for the manufacture of pharmaceuticals. Earlier Nobel prizes had recognised the broader field: aspects of asymmetric catalysis were awarded the Nobel Prize in Chemistry in 2001 and asymmetric organocatalysis in 2021.
The discoveries also bear on the origin of life. The discovery could be the key to understanding how life first arose on Earth, Somfai said. Linke put the point simply: "Life as we know it is homochiral."
Limitations and open questions
The prize does not settle the origin of life. Exactly how life arose favoring one chiral form over another remains a mystery, but this year's laureates' work has helped shed some light on it. The mechanisms of autocatalytic reactions are also still being studied, since the complex equilibria and elusive intermediates make the mechanism difficult to clarify. The committee noted that the research community has been able to better understand asymmetric catalytic reactions, and even to search for new amplification mechanisms.
References
- 2026 Nobel Prize winnersbritannica.com
- Press release: Nobel Prize in Chemistry 2026 - NobelPrize.orgnobelprize.org
- Nobel Prize in Chemistry 2026 - Prize announcement - NobelPrize.orgnobelprize.org
- Henri Kagan and Kenso Soai win 2026 Chemistry Nobel Prizersc.org
- The Nobel Prize in Chemistry 2026kva.se
- The Nobel prize in chemistry 2026 as it happenschemistryworld.com
- 2026 Chemistry Nobel awarded for chiral chemistry advancescen.acs.org
- 2026 Nobel Prize in Chemistry is awarded to Henri Kagan and Kenso Soai for their work in ‘mirror’ chemistryscientificamerican.com
- Nobel Prize in Chemistry 2026nobelprize.org
- Explainer: what are autocatalysis and non-linear effects and why have they won the 2026 Nobel prize in chemistry?chemistryworld.com
- Reactions that demonstrate how homochirality can emerge take chemistry Nobel prizechemistryworld.com
- Mechanistic analysis and kinetic profiling of Soai’s asymmetric autocatalysis for pyridyl and pyrimidyl substratesncbi.nlm.nih.gov
- Henri Kagan and Kenso Soai awarded the Nobel Prize in chemistry for unraveling mystery of mirror moleculescnn.com