An Efficient Ketone-Catalyzed Epoxidation Using Hydrogen Peroxide as Oxidant
Lianhe Shu and Yian Shi
*Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523,
Email: yian.shicolostate.edu
L. Shu, Y. Shi, J. Org. Chem., 2000, 65, 8807-8810.
DOI: 10.1021/jo001180y
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Abstract
Trifluoroacetone catalyzes a mild and operationally simple epoxidation of various alkens in good yields using hydrogen peroxide as primary oxidant at high pH. The use of H2O2 as oxidant significantly reduces the amount of solvent and salts introduced.
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Details
The document discusses an efficient method for ketone-catalyzed epoxidation using hydrogen peroxide (H2O2) as the oxidant. Researchers Lianhe Shu and Yian Shi from Colorado State University found that H2O2, combined with acetonitrile (CH3CN), can be used as a primary oxidant to generate dioxiranes for epoxidation, offering high yields and enantiomeric excesses (ee’s) for various olefins. This method is simpler and requires less solvent and salts compared to traditional procedures using Oxone. Among various ketones tested, trifluoroacetone (CF3COCH3) was identified as a particularly active catalyst. The optimal pH for the reaction was found to be around 11.0, significantly enhancing the conversion rates. The study demonstrated that this catalytic system is effective for a wide range of olefins, including terminal, cyclic, acyclic, trans-, cis-, and trisubstituted olefins, with good yields. The procedure is operationally simple, mild, and reduces the amount of solvent and salt used. The research highlights the potential of CF3COCH3-H2O2-CH3CN as a valuable epoxidation method, providing a practical and efficient approach for organic synthesis. The study was supported by various foundations and pharmaceutical companies.
Key Words
hydrogen peroxide, epoxides, organocatalysis
ID: J42-Y2000