| Summary: | 碩士 === 國立臺灣師範大學 === 化學系 === 96 === Michael addition reaction can create a new carbon-carbon bond and it is one of the important methods in asymmetric syntheses. It is useful in nature product and medicine synthesis. It has economic benefits and environmental protection to do asymmetric Michael addition by utilizing organic catalyst. The L-proline is one of the most well-known organocatalysts used in Michael addition, with high yield and enantioselective excess. How to introduce new functional groups into L-proline to get better result becomes more and more important.
This thesis discuss about the design of new type of organocatalyst. The new organocatalysts 62 and 63 combining camphor and thiourea has been designed and synthesized. Although they can’t get good result in Michael addition and Baylis-Hillman reaction, the ideal of design bifuctional catalyst with combining camphor and thiourea is creative and valuable.
In addition, the new type of organocatalyst 64 combining camphor and L-proline has also been designed and prepared. It shows excellent result to couple β-nitrostyrene and isobutylaldehyde via Michael addition. Herein, we also discuss the effect of solvent, additive, and so on. Furthermore the reaction was treated in brine in the presence of catalyst 64 (20 mol%) and benzoic acid (20 mol%). The yield of desired product is up to 80% and ee value can go up to it’s maximum (90% ee).
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