Department of Chemistry , University of Minnesota-Twin Cities , 207 Pleasant Street SE , Minneapolis , Minnesota 55455 , United States.
Org Lett. 2019 Aug 2;21(15):6149-6154. doi: 10.1021/acs.orglett.9b02331. Epub 2019 Jul 24.
The diazatricyclic core of the madangamine alkaloids was synthesized from a densely functionalized cyclohexane derivative. An alkene and two cyanoformamide groups are used to form two new rings and a new quaternary stereocenter in a cascade reaction, which involves two Pd-catalyzed C-C bond activation steps. The synthesis of the cascade precursor involves an intramolecular Staudinger reaction of a vicinal diester that gives a [3.2.1]azabicyclooctane derivative, allowing the regioselective introduction of a monosubstituted alkene.
马当胺生物碱的二氮杂环庚烷核心是由一个高度官能化的环己烷衍生物合成的。在级联反应中，一个烯烃和两个氰基甲酰胺基团形成两个新环和一个新的季立体中心，涉及两个 Pd 催化的 C-C 键活化步骤。级联前体的合成涉及一个邻位二酯的分子内斯塔丁格反应，生成[3.2.1]氮杂双环辛烷衍生物，允许区域选择性地引入单取代烯烃。
