(k n´ ch f k ´ , f k´ - ) (KEY) , 1918–98, Japanese chemist, b. Nara, Japan, Ph.D. Kyoto Univ., 1948. As a professor at Kyoto Univ., Fukui developed the theory that during chemical reactions molecules share loosely bonded electrons, which occupy so-called frontier orbitals. This theory advanced the understanding of the mechanism of chemical reactions, especially in the production of organic compounds. For his research, Fukui was awarded the 1981 Nobel Prize in Chemistry, which he shared with Roald Hoffmann. He was also known for his efforts to promote science education in Japan.