Enantioselective Desymmetrization of Prochiral Cyclohexanones by Organocatalytic Intramolecular Michael Additions to α,β-Unsaturated Esters
作者:Adam D. Gammack Yamagata、Swarup Datta、Kelvin E. Jackson、Linus Stegbauer、Robert S. Paton、Darren J. Dixon
DOI:10.1002/anie.201411924
日期:2015.4.13
cyclohexanediamine‐derived primary amine organocatalyst, a range of prochiral cyclohexanone derivatives possessing an α,β‐unsaturated ester moiety linked to the 4‐position afforded the bicyclic products, which possess three stereogenic centers, as single diastereoisomers in high enantioselectivity (83–99 % ee) and in good yields (60–90 %). Calculations revealed that stepwise CC bond formation and proton transfer
开发了一种新的催化不对称去对称反应,用于合成 2-氮杂双环[3.3.1]壬烷(许多生物碱常见的关键基序)的对映体富集衍生物。采用环己烷二胺衍生的伯胺有机催化剂,一系列具有与 4 位连接的 α,β-不饱和酯部分的前手性环己酮衍生物提供了具有三个立体中心的双环产物,作为高对映选择性的单一非对映异构体 (83- 99 % ee ) 且收率良好 (60–90 %)。计算表明,逐步的C - C键形成和通过椅形过渡态的质子转移决定了独特的内选择性,并使得高度对映选择性伯胺催化剂的开发成为可能。