| 摘要 |
PROBLEM TO BE SOLVED: To provide an optically active titanium-salan compound useful for asymmetric epoxidation, and to provide a method for efficiently producing the same.SOLUTION: In isolating an optically active titanium-salan compound as a di-μ-oxo titanium-salan complex, the complex has been found to be present as a mixture of three geometrical isomers. By comparing the catalytic performances of the major two geometrical products, it has been found that the homochiral complex gives a higher ultimate yield than that of the pseudo-heterochiral complex in asymmetric epoxidation. In the production of the optically active titanium-salan compound, therefore, a study has been made on production technique which enables efficient formation of the homochiral complex of the optically active titanium-salan compound and which makes it possible to exclude the pseudo-heterochiral complex of the optically active titanium-salan compound as completely as possible. As a result, a technique for producing the homochiral complex of the optically active titanium-salan compound efficiently in a high isolation yield and with high chemical purity has been established by using a nitrile-, ether-, or aromatic hydrocarbon-type organic solvent in the production of the titanium-salan compound. |
