Kinetic resolution of acyclic secondary allylic silyl ethers catalyzed by chiral ketones.
Kinetic resolution of acyclic secondary allylic silyl ethers catalyzed by chiral ketones.
复制标题
手性酮催化的无环仲烯丙基硅醚的动力学拆分。
作者：
D. Yang;G. Jiao;Y. Yip;T. Lai;M. Wong
研究了手性酮(R)-1和(R)-2与氧酮原位合成的手性二氧环烷对无环次生烯丙基硅醚的动力学拆分。已经开发了一种高效的催化方法，用于在α位置具有CCl(3)，叔丁基或CF(3)基团的底物的动力学分辨。特别是，对酮(R)-2催化的外消旋α -三氯甲基烯丙基硅醚7和9-15的动力学拆分观察到高选择性（S高达100）。回收的底物和产生的环氧化物都得到了高对映体过量。基于手性二氧环烷与外消旋底物之间的空间和静电相互作用，提出了手性酮催化的动力学拆分过程中对映选择性和非对映选择性的合理模型。
Kinetic resolution of acyclic secondary allylic silyl ethers by chiral dioxiranes generated in situ from chiral ketones (R)-1 and (R)-2 and Oxone was investigated. An efficient and catalytic method has been developed for kinetic resolution of those substrates with a CCl(3), tert-butyl, or CF(3) group at the alpha-position. In particular, high selectivities (S up to 100) were observed for kinetic resolutions of racemic alpha-trichloromethyl allylic silyl ethers 7 and 9-15 catalyzed by ketones (R)-2. Both the recovered substrates and the resulting epoxides were obtained in high enantiomeric excess. On the basis of steric and electrostatic interactions between the chiral dioxiranes and the racemic substrates, a model was proposed to rationalize the enantioselectivities and diastereoselectivities in the chiral ketone-catalyzed kinetic resolution process.