Gnamm Christian, Brödner Kerstin, Krauter Caroline M, Helmchen Günter
Organisch-Chemisches Institut der Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
Chemistry. 2009 Oct 12;15(40):10514-32. doi: 10.1002/chem.200901316.
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, most often by using Ru-catalyzed cross-metatheses as a key step for introduction of a side chain. Asymmetric total syntheses of the prosopis alkaloids (+)-prosopinine, (+)-prosophylline, (+)-prosopine, and of the dendrobate alkaloid (+)-241D and its C6 epimer are described.
已开发出一种立体选择性合成2,6 - 二取代哌啶的方法，该方法基于使用分子内铱催化的烯丙基取代作为构型转换。该方法可制备对映体过量（ee）大于99%的2 - 乙烯基哌啶。作为应用，已详细阐述了哌啶生物碱的全合成，最常见的是使用钌催化的交叉复分解反应作为引入侧链的关键步骤。描述了豆科生物碱（+） - 豆碱、（+） - 豆叶碱、（+） - 豆碱以及树蛙生物碱（+） - 241D及其C6差向异构体的不对称全合成。
