Lewis base activation of Lewis acids. Vinylogous aidol reactions
Lewis base activation of Lewis acids. Vinylogous aidol reactions
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DOI：
10.1021/ja035448p
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发表时间：
2003-07-02
影响因子：
15
通讯作者：
Beutner, GL
中科院分区：
文献类型：
--
作者：
Denmark, SE;Beutner, GL
开发了一种由 SiCl4 和手性磷酰胺 (R,R)-5 催化的高度区域选择性插烯羟醛反应，为各种醛和二烯醇醚结构提供 δ-羟基烯酮。可以采用低催化剂负载量（1 mol%），使产物具有良好的产率、优异的对映选择性，并且在某些情况下具有优异的反非对映选择性。使用简单的酯衍生的二烯醇醚以及二恶烷酮衍生的二烯醇醚。观察到的区域选择性根据催化剂对亲核试剂的空间需求的敏感性进行合理化。
A highly regioselective vinylogous aldol reaction catalyzed by SiCl4and a chiral phosphoramide (R,R)-5, providing δ-hydroxy enones for a variety of aldehyde and dienol ether structures, has been developed. Low catalyst loadings (1 mol %) can be employed, giving the products in good yields, excellent enantioselectivities, and in some cases excellent anti diastereoselectivities. Both simple ester-derived dienol ethers as well as dioxanone-derived dienol ethers are employed. The observed regioselectivity is rationalized in terms of the sensitivity of the catalyst to the steric demands of the nucleophile.