Kagan and Soai awarded 2026 Nobel Prize in Chemistry for work on mirror-image molecules

Henri B. Kagan and Kenso Soai were awarded the 2026 Nobel Prize in Chemistry, the Royal Swedish Academy of Sciences announced in Stockholm on Wednesday, 7 October 2026, according to ABC News Australia, for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis. Kagan, born in France and affiliated with Université Paris-Sud in Orsay, is 95, and Soai, born in Japan and affiliated with the Tokyo University of Science, is 76, according to STAT News; the New York Post also reports Kagan's age as 95. Heiner Linke, chair of the Nobel Committee for Chemistry, said the two provided a solution to a chemical mystery more than a century old — how homochirality can emerge spontaneously — and described the reactions they developed as spectacular, according to ABC News Australia and the New York Post. The prize money is 12 million Swedish kronor, which ABC News Australia states is $1.71 million and which the New York Post and STAT News describe as about $1.2 million.

ABC News Australia and STAT News give the citation as the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis. The New York Post and ABC News Australia report the award was announced by the Royal Swedish Academy of Sciences in Stockholm. Ars Technica describes the prize as going to two researchers who found that chemical reactions could be biased to produce large excesses of one of two mirrored forms of a molecule.

The chemistry at issue is chirality, or molecular handedness. Ars Technica explains that many molecules can form mirror-image versions with the same parts arranged differently in space, and that life relies on only one of the forms — amino acids, the building blocks of proteins, come in both forms but organisms use only one, according to STAT News. STAT News reports that more than half of clinically employed drugs are chiral, that such drugs are typically sold as racemates containing equal mixtures of both forms, and cites the cough medicine novrad and the painkiller darvon as chiral molecules whose mirror versions can act differently, with mirror forms sometimes causing serious side effects. ABC News Australia notes that one mirror image of the chemical carvone smells like mint while the other has a whiff of caraway.

On Kagan's contribution, STAT News reports that in 1986 he found a way to manipulate chemical reactions so they produced more of one type of mirror image. Ars Technica describes Kagan as approaching the work theoretically before finding real reactions, working with a chiral catalyst in which one form was much more active than the other, and states that by the mid-1960s Kagan had found three reactions that could produce an excess of a single chiral form; it adds that later researchers showed chiral catalysts could be selectively activated or inhibited by non-chiral chemicals, a degree of control that found its way into pharmaceutical production.

On Soai's contribution, STAT News reports that seventeen years after Kagan's finding he developed an experiment creating only one of the two variants, producing a chiral molecule from a non-chiral combination of molecules for the first time since the dawn of life, and that the experiment is known as the Soai reaction. Ars Technica describes Soai, whom it places at Tokyo University, as working on reactions where a product acts as a catalyst for the same reaction, and reports that starting with a slight excess of one catalyst form, the excess rose to 55 percent after one round and, after several rounds, 90 percent of products were of a single chirality. ABC News Australia states that the Soai reaction is named for the experiment.

Nobel Committee members commented on the work. STAT News quotes committee member Peter Somfai calling it probably the coolest experiment in organic chemistry, referring to the Soai reaction. Heiner Linke, the committee chair, is quoted by ABC News Australia and the New York Post on the century-old mystery and on the reactions being spectacular. ABC News Australia reports the research has been decisive for chemists who design reactions for the manufacture of pharmaceuticals.

Soai responded to the award. The New York Post reports he said he was shopping near his home when reached by the Nobel committee. STAT News reports he called into the award ceremony at the Karolinska Institutet in Stockholm from his native Hiroshima, Japan, saying he was very excited to receive the news and that it was one of the most exciting days of his life, and that he was glad to share the award with professor Kagan. No statement from Kagan appears in any of the supplied sources.

Ars Technica reports that several ideas about how one chiral form could dominate trace back to physicist Frederick Charles Frank, who addressed the question in a theory-focused paper, and states that it is clear from the Nobel Committee's writing that Frank might have shared in the award were he still alive. Ars Technica also outlines proposed mechanisms such as a slightly selective catalyst producing a large excess over time, a chiral product catalysing its own formation, or a chiral product inhibiting its mirror form.

STAT News reports the chemistry prize has been awarded 118 times since 1901, with 202 winners of whom 8 are women, and 200 individuals because Frederick Sanger and Barry Sharpless each won twice; the youngest recipient was 35 and the oldest 97, with 63 prizes to a single laureate, 26 shared by two and 29 shared by three.

Other 2026 prizes were noted. ABC News Australia and the New York Post report the medicine prize went on Monday to three scientists whose work led to a tool using light to help unravel how the brain works, and the physics prize on Tuesday recognised a scientist's efforts to demystify a rare group of neutrinos. Both outlets state the literature prize is due Thursday, the peace prize Friday and the economics prize Monday. Both also note that last year three scientists won the chemistry Nobel for developing molecular structures that can trap large quantities of gas. STAT News states the medicine and physics prizes were awarded earlier in the week.

A fifth supplied source, NPR, addresses the upcoming economics prize rather than the chemistry award. NPR reports the economics announcement is scheduled for Monday and that, as of Tuesday afternoon, 6 October, a prediction market on the winner had recorded about $11,000 in trading volume, far below the roughly $670 million it says Kalshi's main market for the 2024 US presidential election recorded. NPR states that by late Tuesday afternoon Ariel Pakes and Susan Athey were trading places at the top of Kalshi's rankings, with Robert Barro rounding out the top three, and describes Pakes's work on industrial organisation and the BLP method and Athey's work on the economics of technology and her 2007 John Bates Clark Medal.

Where sources differ

• Prize money: ABC News Australia reports 12 million Swedish kronor as $1.71 million, while the New York Post and STAT News describe the same 12 million Swedish kronor as about $1.2 million.
• Soai's institution: Ars Technica places Kenzo Soai at 'Tokyo University'; ABC News Australia, the New York Post and STAT News state he is affiliated with the Tokyo University of Science.
• Timing of Kagan's key work: Ars Technica states that by the mid-1960s Kagan had found three reactions producing an excess of a single chiral form, while STAT News states that in 1986 Kagan found a way to manipulate reactions to produce more of one mirror image.
• Gap between the two researchers' work: Ars Technica describes Soai's autocatalysis work as coming about a decade after Kagan's, while STAT News states Soai's experiment came seventeen years after Kagan's 1986 finding.
• Naming of laureates: Ars Technica refers to the winners as Henri Kagan and Kenso Soai, while ABC News Australia, the New York Post and STAT News give the first laureate's name as Henri B. Kagan.
• Scope of coverage: four sources report on the chemistry award while NPR reports on the forthcoming economics prize and the prediction market around it.

• No statement, reaction or comment from Henri B. Kagan appears in any of the supplied sources.
• No source states Kagan's reaction to the award or confirms whether he was reached by the committee.
• No source explains the discrepancy between the mid-1960s and 1986 dates attributed to Kagan's key work, or between the 'about a decade' and 'seventeen years' intervals attributed to Soai's follow-up work.
• No source clarifies whether Soai's affiliation is Tokyo University or Tokyo University of Science.
• No source explains the difference between the $1.71 million and roughly $1.2 million dollar valuations of the 12 million Swedish kronor prize sum, or which currency each figure is expressed in.
• No source states the exact wording of the full Nobel citation beyond the phrase 'for their discovery of non-linear effects and autocatalysis in asymmetric organic synthesis'.
• No source confirms or elaborates on Ars Technica's suggestion that Frederick Charles Frank might have shared the award.
• No source reports independent verification of the committee's account of the research's impact on pharmaceutical manufacturing.
• None of the sources reports the date of the chemistry announcement as anything other than Wednesday 7 October 2026, and no source states whether either laureate attended the ceremony in person.

1. Ars Technica — original — by John Timmer
2. ABC News Australia
3. New York Post — by Associated Press
4. STAT News — by Annalisa Merelli
5. NPR News — by Greg Rosalsky

Read the original at Ars Technica

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