Dynamic Kinetic Resolution via Asymmetric Conjugate Reduction: Enantio- and Diastereoselective Synthesis of 2,4-Dialkyl Cyclopentanones
作者:Valdas Jurkauskas、Stephen L. Buchwald
DOI:10.1021/ja025603k
日期:2002.3.1
Herein, we report the kinetic and the dynamic kinetic resolutions of racemic 3,5-dialkyl-2-cyclopenten-1-ones. Kinetic resolution, with good selectivity factors (25-52), was achieved by conjugate reduction with catalytic CuCl/NaOt-Bu/(S)-p-tol-BINAP and stoichiometric quantities of poly(methylhydrosiloxane) (PMHS). When stoichiometric amounts of NaOt-Bu and t-BuOH were included in the reaction mixture
在此,我们报告了外消旋 3,5-dialkyl-2-cyclopenten-1-ones 的动力学和动态动力学分辨率。具有良好选择性因子 (25-52) 的动力学拆分是通过与催化 CuCl/NaOt-Bu/(S)-p-tol-BINAP 和化学计量数量的聚(甲基氢硅氧烷)(PMHS)共轭还原来实现的。当反应混合物中包含化学计量的 NaOt-Bu 和 t-BuOH 时,会发生起始材料的快速外消旋化,从而实现环戊烯酮底物的动态动力学拆分。在该过程中,手性 2,4-二烷基环戊酮以高立体选择性(ee > or = 91%,dr > or = 90:10)和高产率(> or = 89%)分离。