| abstract |
An asymmetric reaction catalyst is obtained by mixing a pentavalent niobium compound and an optically active triol or tetraol having a binaphthol structure of R or s configuration, and the triol is represented by the following formula: n n n n n n n n n n wherein, Y is divalent hydrocarbon and R I is a hydrogen atom, a halogen atom, a trifluoromethyl group, or an alkyl group or alkoxy group having at most 4 carbons. |