Asymmetric Organocatalytic Protonation of Silyl Enolates Catalyzed by Simple and Original Betaines Derived from Cinchona Alkaloids
Asymmetric Organocatalytic Protonation of Silyl Enolates Catalyzed by Simple and Original Betaines Derived from Cinchona Alkaloids
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DOI：
10.1002/ejoc.201301345
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发表时间：
2013-12-01
影响因子：
2.8
通讯作者：
Levacher, Vincent
中科院分区：
文献类型：
--
作者：
Claraz, Aurelie;Landelle, Gregory;Levacher, Vincent
通过使用简单而原始的辛可纳生物碱(奎宁和奎尼丁系列)衍生的甜菜碱催化剂，以较高的产率和中等的对映选择性，成功地实现了由丁酮、苯并琥珀酮和环己酮衍生的硅烯醇酸酯的不对称质子化反应。该方法易于实现，并且甜菜碱催化剂易于获得(与廉价的商业可获得的奎宁或奎尼丁相距四步)，这使得该方法对于制备对映体富含α的单取代羰基化合物非常有吸引力。
The asymmetric protonation of silyl enolates derived from tetralone, benzosuberone, and cyclohexanone has been successfully achieved by using simple and original betaine catalysts derived fromCinchonaalkaloids (quinine and quinidine series) to afford the desired α‐substituted ketones in high yields and moderate enantioselectivities. The ease of implementation of this approach along with the easy accessibility of the betaine catalyst (four steps from cheap and commercially available quinine or quinidine) make this approach very appealing for the preparation of enantioenriched α‐monosubstituted carbonyl compounds.