학술논문
Effect of Calix[4]arene as a Hydrophobic Substituent on Proline Catalysis of Direct Asymmetric Aldol Reactions in the Presence of Water.
Document Type
Article
Author
Source
Subject
*ALDOLS
*CATALYSIS
*PROLINE
*AROMATIC aldehydes
*CYCLOHEXANONES
*ORGANOCATALYSIS
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Language
ISSN
1070-3632
Abstract
A new organocatalyst trans-4-hydroxy-L-proline-derived calix[4]arene was synthesized and its catalyst performance for the direct asymmetric aldol reactions between cyclohexanone and different aromatic aldehydes was investigated. The effect of a series of reaction conditions such as solvent, water and additives were evaluated in detail, and it was observed that the addition of water had a big effect on the enantioselectivities. Specifically, high anti-diastereoselectivity (anti/syn = 92 : 8) and high enantioselectivity (ee 88%) were obtained from the reaction between cyclohexanone and 4-fluorobenzaldehyde in the presence of water. [ABSTRACT FROM AUTHOR]