Asymmetric Organocatalytic Protonation of Silyl Enolates Catalyzed by Simple and Original Betaines Derived from<i>Cinchona</i>Alkaloids
作者:Aurélie Claraz、Grégory Landelle、Sylvain Oudeyer、Vincent Levacher
DOI:10.1002/ejoc.201301345
日期:2013.12
The asymmetric protonation of silyl enolates derived from tetralone, benzosuberone, and cyclohexanone has been successfully achieved by using simple and original betaine catalysts derived from Cinchona alkaloids (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
通过使用源自金鸡纳生物碱(奎宁和奎尼丁系列)的简单而原始的甜菜碱催化剂,成功地实现了衍生自四氢萘酮、苯并芴酮和环己酮的甲硅烷基烯醇化物的不对称质子化,以高产率和中等对映选择性提供所需的 α-取代酮。这种方法易于实施以及甜菜碱催化剂易于获得(从廉价和市售奎宁或奎尼丁开始的四个步骤)使这种方法对于制备对映体富集的 α-单取代羰基化合物非常有吸引力。