Henri B. Kagan and Kenso Soai won the 2026 Nobel Prize in Chemistry on Wednesday. The Royal Swedish Academy of Sciences awarded the prize for their discoveries in non-linear effects and autocatalysis in asymmetric organic synthesis, resolving a century-old chemical puzzle.
The Royal Swedish Academy of Sciences announced the chemistry prize in Stockholm, honoring two chemists whose work fundamentally changed how scientists understand molecular chirality. The award recognizes Henri B. Kagan and Kenso Soai for breakthroughs that explain how tiny initial asymmetries in chemical reactions can amplify into dominant molecular forms. Heiner Linke, chair of the Nobel Committee for Chemistry, stated that the pair provided a solution to a chemical puzzle spanning more than a century and described the chemical reactions they developed as astonishing. The Nobel Committee for Chemistry explained that their discoveries played a decisive role for chemists inventing tailored reactions for pharmaceutical manufacturing. Part of that sector previously won a prize in 2001, though it was not awarded to Kagan, who is considered in France and globally to be the “father” of the technique.
Resolving Mirror-Image Molecules for Modern Pharmaceuticals
Many biological molecules exist in two mirror-image versions that look identical on paper but behave quite differently in nature. A classic example is the chemical carvone, where one mirror image smells like mint while the other carries a whiff of caraway. For pharmaceutical researchers designing treatments, controlling which mirror image emerges from a reaction is essential to ensuring a medicine works effectively without unwanted side effects.
Kagan and Soai designed and manipulated chemical reactions to produce the desired mirror-image version. Their discoveries provided a crucial framework for chemists creating tailored reactions used in drug manufacturing.
Decades of Discovery From France to Japan
Born in France in 1930, Kagan studied at the Sorbonne in Paris and earned his doctorate from the Collège de France in 1960. In the 1980s, Kagan’s work showed there might be a way to design reactions to produce one form of a molecule over the other. The French Academy of Sciences congratulated both scientists and expressed its pride in the award.
Soai was born in Hiroshima, Japan, in 1950, graduated from the University of Tokyo, and completed his doctorate in 1979. Now a professor at the Tokyo University of Science, Soai built upon Kagan’s foundation by discovering autocatalysis in asymmetric synthesis — demonstrating that a reaction product can actively promote the pathway that created it.
I’m very excited to receive the very nice news. Of course this is one of the most exciting days in my life.
Soai told journalists and the Nobel committee that he was out shopping near his home when the committee reached him by telephone.
Winners Receive Medals and Cash Awards in December
The Nobel Prize consists of a diploma, a gold medal, and a cash award of 12 million Swedish kronor (about $1.2 million), which is shared when multiple laureates win the same discipline. The winners will receive their awards at a formal ceremony on December 10, the anniversary of Alfred Nobel’s death.
Following Thursday’s literature prize and Friday’s peace prize, the Nobel Prize in Economic Sciences will conclude the announcements on Monday.
