Lewis Base Activation of Lewis Acids. Vinylogous Aldol Reactions
作者:Scott E. Denmark、Gregory L. Beutner
DOI:10.1021/ja035448p
日期:2003.7.1
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
已开发出由 SiCl4 和手性磷酰胺 (R,R)-5 催化的高度区域选择性的乙烯醇醛反应,为各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 mol %),从而使产品具有良好的产率、出色的对映选择性,在某些情况下还具有出色的抗非对映选择性。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在催化剂对亲核试剂的空间需求的敏感性方面被合理化。