Abstract
The practicality of Ti(salan)-catalyzed asymmetric epoxidation was significantly improved by the addition of phosphate buffer (pH 7.4-8.0). Various olefins were transformed on a multigram scale into the corresponding epoxides with nearly complete product selectivity as well as high to excellent enantioselectivity in the presence of 1 mol% of the catalyst and the buffer.
Key words
asymmetric catalysis - epoxidation - titanium - hydrogen peroxide - green chemistry
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12 In a large-scale synthesis, the addition of an excess amount of ligand was not required, while the excess ligand was added in a small scale in order to obtain reproducibility.
