The Chemistry of Trichlorosilyl Enolates. Aldol Addition Reactions of Methyl Ketones
作者:Scott E. Denmark、Robert A. Stavenger
DOI:10.1021/ja001023g
日期:2000.9.1
observed in this uncatalyzed aldol process. The aldol additions are dramatically accelerated by the addition of catalytic quantities of chiral phosphoramides, particularly one derived from N,N‘-dimethylstilbene-1,2-diamine. In this catalyzed mode, good to high enantioselectivities are obtained with a variety of achiral trichlorosilyl enolates and aldehydes. When either partner bears a stereogenic center
对衍生自甲基酮的三氯甲硅烷基烯醇化物的羟醛加成化学进行了全面的研究。这些三氯甲硅烷基烯醇化物在没有添加剂的情况下是有效的醛醇试剂,在环境温度下与醛反应以提供高产率的醛醇加合物。当烯醇或醛伙伴带有立体中心时,在这种未催化的羟醛过程中观察到低非对映选择性。通过添加催化量的手性磷酰胺,特别是衍生自 N,N'-二甲基二苯乙烯-1,2-二胺的手性磷酰胺,醛醇的添加显着加速。在这种催化模式下,使用各种非手性三氯甲硅烷基烯醇化物和醛可以获得良好到高的对映选择性。当任何一方都带有立体中心时,使用催化剂的一种对映异构体(匹配情况)获得高非对映选择性,而另一种对映异构体提供低非对映选择性(不匹配情况)。反应范围、条件优化...