Design of highly functional small-molecule catalysts and related reactions based on acid-base combination chemistry

The design of small but highly functional artificial catalysts is very important for practical organic synthesis. We have succeeded in the rational design of small and simple catalysts and related reactions based on acid-base combination chemistry. Acid-base combined catalysts can be classified into three types: (i) acid-base combined salt catalysts, (ii) conjugate acid-base catalysts, and (iii) nonconjugate acid-base catalysts. We have systematically developed acid-base combined salt catalysts such as ammonium salts, ate complexes, ion pairs and cation-pi complexes, acid-base conjugate catalysts such as metal oxides (monoconjugation) and zinc(Il)3,3'-diphosphinol-BINOLates (triconjugation), and acid-base nonconjugate catalysts like L-histidine-derived sulfonamides.