Denmark Scott E, Beutner Gregory L
Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL 61801, USA.
J Am Chem Soc. 2003 Jul 2;125(26):7800-1. doi: 10.1021/ja035448p.
A highly regioselective vinylogous aldol reaction catalyzed by SiCl4 and a chiral phosphoramide (R,R)-5, providing delta-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.
已开发出一种由四氯化硅和手性磷酰胺（R，R）-5催化的高度区域选择性乙烯基烯醇醛反应，该反应可为多种醛和二烯醇醚结构提供δ-羟基烯酮。可以使用低催化剂负载量（1摩尔%），以良好的产率、优异的对映选择性，并且在某些情况下以优异的非对映选择性得到产物。既使用了简单酯衍生的二烯醇醚，也使用了二恶烷酮衍生的二烯醇醚。根据催化剂对亲核试剂空间需求的敏感性，对观察到的区域选择性进行了合理化解释。
