The first catalytic enantioselective Fischer indolization of prochiral diketones containing enantiotopic carbonyl groups is developed and shown to proceed through dynamic kinetic resolution (DKR). Catalyzed by the combination of a spirocyclic chiral phosphoric acid and ZnCl2 (Lewis acid assisted Brønsted acid), this direct approach combines 2,2‐disubstituted cyclopentane‐1,3‐diones with N‐protected
包含对映体羰基的前手性二酮的第一个催化对映选择性菲舍尔吲哚化反应已经开发出来,并显示通过动态动力学拆分(DKR)进行。通过螺环手性磷酸和ZnCl 2(路易斯酸辅助的布朗斯台德酸)的组合催化,这种直接方法将2,2–二取代的环戊烷-1,3-二酮与N保护的苯肼结合起来,制得环戊[ b ]吲哚衍生物包含全碳四元立体中心,具有良好至出色的对映选择性。
A short total synthesis of (±)-mersicarpine <i>via</i> visible light-induced cascade photooxygenation
作者:Mario Frahm、Alice Voss、Malte Brasholz
DOI:10.1039/d2cc01316a
日期:——
A short total synthesis of the Kopsia alkaloid (±)-mersicarpine is presented. As the key step, a visible light-induced catalytic cascade photooxygenation was utilized, to convert a 3,3-disubstituted tetrahydrocarbazole intermediate, in one step, into a perhydropyrido[1,2-a]indole dione as the immediate precursor to the natural product. The synthesis of mersicarpine was achieved with an overall yield
介绍了Kopsia生物碱 (±)-mersicarpine的简短全合成。作为关键步骤,利用可见光诱导的催化级联光氧化,一步将 3,3-二取代四氢咔唑中间体转化为全氢吡啶并[1,2- a ]吲哚二酮作为天然产物的直接前体。产品。mersicarpine 的合成经过 13 个步骤以 12% 的总产率实现。