Diastereoselective Trifluoroacetylation of Highly Substituted Pyrrolidines by a Dakin−West Process
作者:Marcus Baumann、Ian R. Baxendale
DOI:10.1021/acs.joc.6b02346
日期:2016.12.2
generation of the desired trifluoroacetylation products, which was not possible previously due to the exclusive formation of trifluoromethylated oxazoles (vide infra). In the course of this work we succeeded for the first time in isolating and characterizing (HRMS, IR, 1H, 13C and 19F NMR, X-ray) different intermediates of the Dakin–West reaction allowing us to probe its mechanism.
报道了一种可靠的方法,该方法允许以非对映选择性方式对一系列高度取代的吡咯烷进行有效的三氟乙酰化。该转化基于高级吡咯烷2-羧酸衍生物的Dakin-West反应,可以在四个合成步骤中进行立体选择性组装。重要的是,这项工作证明了在吡咯烷支架上引入侧向取代基如何能够产生所需的三氟乙酰化产物,这是以前由于三氟甲基化恶唑的独家存在而无法实现的(见下文)。在这项工作的过程中,我们首次成功地进行了分离和表征(HRMS,IR,1 H,13 C和19核磁共振,X射线)Dakin-West反应的不同中间体使我们能够探究其机理。