Henri Kagan and Kenso Soai Win 2026 Nobel Prize in Chemistry

The Royal Swedish Academy of Sciences announced on Wednesday, October 7, that the 2026 Nobel Prize in Chemistry goes jointly to Henri B. Kagan and Kenso Soai "for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis." The announcement was made in Stockholm, continuing the week's sequence of Nobel announcements that began with physiology or medicine on Monday and physics on Tuesday.

Kagan, from France, and Soai, from Japan, are both 95 years old. Kagan is an emeritus professor affiliated with Université Paris-Sud (now part of Université Paris-Saclay) in Orsay, while Soai is associated with the Tokyo University of Science.

Who are the laureates

Kagan was born on December 15, 1930, in Boulogne-Billancourt, France. He studied at the Sorbonne and the École nationale supérieure de chimie de Paris, and completed his doctorate under J. Jacques at the Collège de France, according to his Wikipedia biography. He is described there as "a pioneer in the field of asymmetric catalysis," known for developing C2-symmetric ligands such as DIOP.

What the discovery is about

Asymmetric, or chiral, molecules can exist in two mirror-image forms, much like left and right hands. Chemists have long sought reliable ways to produce only one of the two forms, since in biology and medicine the two mirror images of a molecule can behave very differently. In 1986, Kagan observed and mathematically modeled what are called non-linear effects in asymmetric catalysis — cases where the purity of one chiral form in a catalyst does not translate proportionally into the purity of the product, according to his Wikipedia entry.

Soai's contribution is an autocatalytic reaction, now known as the Soai reaction, in which a chiral molecule catalyzes its own formation, amplifying a tiny initial imbalance between the two mirror-image forms into an overwhelming excess of one of them. Member station WCMU, citing the Nobel Committee, reported that the chair of the Nobel Committee for Chemistry said the two laureates "provided a solution to a chemical mystery that is over a century old: how homochirality can emerge spontaneously." The same committee chair, identified by WCMU as Heiner Linke, was quoted saying: "The chemical reactions they have developed are spectacular."

Why it matters

The phenomenon the laureates explained — homochirality, the dominance of one mirror-image form of a molecule in living systems — bears on long-standing questions about the origin of life, according to Kagan's Wikipedia biography, which notes his work's applications span molecular mechanisms and origin-of-life research. WCMU reported that the Soai reaction has also proven useful in the manufacture of pharmaceuticals, where producing a single chiral form of a drug molecule is often essential.

Prize details and context

Each Nobel Prize this year carries an award of 12 million Swedish kronor, about $1.2 million, shared between the laureates, according to WCMU and Israeli outlet Ynetnews. Indian broadcaster ETV Bharat reported that the Chemistry Prize had been awarded 117 times to 200 laureates between 1901 and 2025, and noted that the oldest previous laureate was John B. Goodenough at 97, while the youngest was Frédéric Joliot at 35.

Ynetnews reported that last year's Chemistry Prize, in 2025, recognized researchers working on metal-organic framework structures with applications including gas capture; ETV Bharat similarly described the 2025 award as covering metal-organic frameworks. Nobel announcements for literature and peace were scheduled to follow later in the week.