A Configurational Switch Based on Iridium-Catalyzed Allylic Cyclization: Application in Asymmetric Total Syntheses of Prosopis, Dendrobate, and Spruce Alkaloids
作者:Christian Gnamm、Kerstin Brödner、Caroline M. Krauter、Günter Helmchen
DOI:10.1002/chem.200901316
日期:2009.10.12
A method for the stereoselective synthesis of 2,6‐disubstituted piperidines has been developed that is based on the use of an intramolecular iridium‐catalyzed allylic substitution as a configurational switch. The procedure allows the preparation of 2‐vinylpiperidines with enantiomeric excesses (ee) of greater than 99 %. As applications, total syntheses of piperidine alkaloids have been elaborated,
基于分子内铱催化的烯丙基取代作为构型转换,已开发出一种立体选择合成2,6-二取代哌啶的方法。该程序可以制备对映体过量(ee)大于99%的2-乙烯基哌啶。作为应用,已经详细说明了哌啶生物碱的总合成,大多数情况下是通过使用Ru催化的交叉金属作为引入侧链的关键步骤。描述了Prosopis生物碱(+)-prosopinine,(+)-prosophylline,(+)-prosopine和树状生物碱(+)-241D及其C6差向异构体的不对称总合成。