Abstract
Several new cyclodextrin ketones with a ketone attached to the secondary face of the cyclodextrin in the form of a 2,3-O-(2-oxopropane-1,3-diyl) or 2-oxo group are reported. These compounds and a selection of known cyclodextrin ketones having the ketone at the primary face were investigated as epoxidation catalysts for oxidation of stilbenes and styrene. A method for determination of kcat in these epoxidations is presented, which was used to determine the rate accelerations for the cyclodextrin ketones relative to background reaction. The highest rate acceleration obtained for epoxidation of 4-methoxy-4′-nitro-trans-stilbene was 221. The highest enantioselectivity obtained was 76% ee of (S)-styrene oxide. A cyclodextrin bearing a ketone on the secondary face can catalyze the epoxidation of stilbenes with cavity induced rate increases of 100-200 and stereoselectivity.
Originalsprog | Engelsk |
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Tidsskrift | European Journal of Organic Chemistry |
Sider (fra-til) | 2339-2345 |
Antal sider | 7 |
ISSN | 1434-193X |
Status | Udgivet - apr. 2011 |