Natural products have long been important inspirations for the development of chemical methodologies, theories, and technologies, and ultimately, discoveries of new drugs and materials. Chemical syntheses have traditionally yielded individual or small groups of natural products; however, methodology development allowing the synthesis of a large collection of natural products remains scarce. Here, we
designed to assemble the functionalized piperidines present in indole alkaloids from a common intermediate. More importantly, we also report a previously unknown Ir- and Er-catalyzed dehydrogenative spirocyclization reaction that enables direct access to spirocyclic oxindole alkaloids. As a practical application, the asymmetric total syntheses of 29 natural alkaloids belonging to different families were
天然产物及其类似物是治疗性先导化合物的重要来源。然而,产生大量这些分子的合成策略仍然是一个重大挑战。合成过程中最困难的步骤是设计一种通用中间体,该中间体可以很容易地转化为属于不同家族的天然产物。这项研究展示了合成策略的演变,该策略旨在从常见中间体组装吲哚生物碱中存在的功能化哌啶。更重要的是,我们还报道了一种以前未知的 Ir 和 Er 催化的脱氢螺环化反应,该反应能够直接获得螺环羟吲哚生物碱。作为实际应用,遵循统一的合成路线,完成了属于不同科的29种天然生物碱的不对称全合成。所提出的方法将铱催化脱氢偶联反应的能力扩展到吲哚生物碱合成领域,并为有效制备天然产物类分子提供了新的机会。
A Stereodivergent Strategy for the Preparation of Corynantheine and Ipecac Alkaloids, Their Epimers, and Analogues: Efficient Total Synthesis of (−)-Dihydrocorynantheol, (−)-Corynantheol, (−)-Protoemetinol, (−)-Corynantheal, (−)-Protoemetine, and Related
Here we present a general and common catalytic asymmetric strategy for the total and formal synthesis of a broad number of optically active natural products from the corynantheine and ipecac alkaloid families, for example, indolo[2,3‐a]‐ and benzo[a]quinolizidines. Construction of the core alkaloid skeletons with the correct absolute and relative stereochemistry relies on an enantioselective and diastereodivergent
在这里,我们提出了一种通用和通用的催化不对称策略,用于从大红霉素和吐根碱生物碱家族中广泛合成光学活性天然产物,例如吲哚[2,3- a ]-和苯并[ a]]喹唑烷。具有正确的绝对和相对立体化学的核心生物碱骨架的构建依赖于对映选择性和非对映异构单锅级联序列,然后进行额外的非对映异构反应步骤。这允许对喹诺酮生物碱的四种可能的差向异构体中的三种进行对映异构和非对映选择性合成,这些异构体是通过使用常见的合成途径从常见且易于获得的起始原料开始的。已经集中在排除保护基和限制合成中间体的分离和纯化上。该方法适用于天然产物(-)-二氢甲氧萘酚,(-)-水苏糖醇,(-)-甲氧萘酚,(-)-异丙甲酚,(-)-二氢甲氧萘酚,(-)-甲氧乙醛,(- )-protoemetine,( - ) - (15小号)-羟基二氢二十烷醇及其一系列非天然差向异构体。这种策略的潜力在合成生物学上令人感兴趣的天然产物类似物时也得到了
Indole C5‐Selective Bromination of Indolo[2,3‐a]quinolizidine Alkaloids via In Situ‐Generated Indoline Intermediate
The indole C5-selective bromination of indolo[2,3-a]quinolizidine alkaloids by adding nearly equimolar amounts of Br3 ⋅ PyH and HCl in MeOH is disclosed. The resulting reaction plausibly proceeds through an indoline intermediate by the nucleophilic addition of MeOH to the C3-brominated indolenine intermediate. These simple, mild, and metal-free conditions are suitable for late-stage chemical conversions
公开了通过在MeOH中添加几乎等摩尔量的Br 3 ·PyH和HCl来对吲哚并[2,3- a ]喹啉西啶生物碱进行吲哚C5选择性溴化。通过将MeOH亲核加成至C3-溴化吲哚啉中间体,所得反应似乎通过二氢吲哚中间体进行。这些简单、温和且不含金属的条件适用于全合成和药物化学中的后期化学转化。