Kensō Soai

Soai studied at the University of Tokyo, where he received his Ph.D. in 1979 in organic synthesis under Teruaki Mukaiyama and was a fellow of the Japan Society for the Promotion of Science. He conducted his postdoctoral studies with Ernest L. Eliel at the University of North Carolina. In 1981, he became a lecturer at Tokyo University of Science, and was promoted to associate professor (1986) and full professor (1991).^[2] In 2026, he was jointly awarded the Nobel Prize in Chemistry with Henri B. Kagan "for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis." ^[3]

He is involved in asymmetric and enantioselective synthesis, asymmetric autocatalysis, and the origin of chirality.^[4] In 1995, Soai discovered a reaction with the chiral compound 5-pyrimidyl alkanol that produced almost exclusively one of the two mirror-image forms of a molecule as a product, mimicking a process found in living organisms.^[5] In 2003, he was able to demonstrate this reaction with nonchiral reactants.^[6][7][8] Specifically, the Soai reaction for alkylation of pyrimidine-5-carbaldehyde with diisopropylzinc is named after him. In this reaction, both reactants, which are non-chiral, produce the chiral product pyrimidyl alcohol, which further induces that same chirality in subsequent catalytic cycles.^{[9][10][11][5]}

Soai was a visiting professor at several universities such as the ESPCI Paris (2001), Kyushu University (2005), Waseda University (2007–2010), University of Strasbourg (2008), and Jilin University (2010–2015).^[2] He retired as a professor in 2016.^[8]

• Inoue Prize (2000)^[12]
• Chirality Medal (2005)^[13]
• Honorary member of the Italian National Academy of Sciences (2006)^[2]
• Science and Technology Prize from MEXT, the Japanese Ministry of Education, Culture, Sports, Science and Technology (2007)^[2]
• Chemical Society of Japan Award (2010)^[14]
• Purple Ribbon Medal^[15] (2012)
• Doctor Honoris Causa, University of Pannonia, Hungary (2015)^[2]
• Third Class of the Order of the Sacred Treasure^[16] (2023)
• Japan Academy Prize (2025)^[17]
• Nobel Prize in Chemistry (2026)^[3]

In its 2026 Nobel announcement, the Royal Swedish Academy of Sciences highlighted Soai's progression from his 1995 work on asymmetric autocatalysis to a 2003 reaction producing one of two possible mirror-image forms. It placed these results in the study of homochirality and the design of pharmaceutical synthesis. The prize money was shared equally with Henri B. Kagan.^[18]

• Mukaiyama, Teruaki; Soai, Kenso; Sato, Toshio; Shimizu, Hisashi; Suzuki, Keisuke (1979). "Enantioface-differentiating (asymmetric) addition of alkyllithium and dialkylmagnesium to aldehydes by using (2S,2'S)-2-hydroxymethyl-1-[(1-alkylpyrrolidin-2-yl)methyl]pyrrolidines as chiral ligands". Journal of the American Chemical Society. 101 (6). American Chemical Society (ACS): 1455–1460. Bibcode:1979JAChS.101.1455M. doi:10.1021/ja00500a015. ISSN 0002-7863.
• Soai, Kenso; Shibata, Takanori; Morioka, Hiroshi; Choji, Kaori (1995). "Asymmetric autocatalysis and amplification of enantiomeric excess of a chiral molecule". Nature. 378 (6559): 767–768. Bibcode:1995Natur.378..767S. doi:10.1038/378767a0. ISSN 0028-0836. Retrieved 7 October 2026.
• Sato, Itaru; Urabe, Hiroki; Ishiguro, Saori; Shibata, Takanori; Soai, Kenso (20 January 2003). "Amplification of Chirality from Extremely Low to Greater than 99.5 % ee by Asymmetric Autocatalysis". Angewandte Chemie International Edition. 42 (3): 315–317. Bibcode:2003ACIE...42..315S. doi:10.1002/anie.200390105. ISSN 1433-7851. PMID 12548688. Retrieved 7 October 2026.