Dimeric indolosesquiterpenoids have drawn significant interest in the synthetic community due to their higher potential for biological activity than their monomeric congeners. Biosynthetically, it has been shown that xiamycin A (2a) could be dimerized under oxidative conditions to form the more potent all-possible N–N, C–N, and C–C dimers. The pursuit of effective methods for creating these linkages has driven the advancement of synthetic chemistry, leading to new strategies and tools that enhance the ability to produce these biologically significant molecules. To date, the synthesis and biological evaluation of the dimer of oridamycin A remain unexplored. Herein, we have described a synthetic design towards the concise total synthesis of dioridamycin (1a) and the C–C dimer of xiamycin A (1b) following the strategic use of hypervalent iodine(III) to forge intramolecular cross-amination leading to the indolosesquiterpenoid pentacyclic core under mild and atom-economical conditions. Our study reveals the utility of PhI(OAc)₂ for the introduction of intramolecular C–N bonds for indolosesquiterpenoids, which has conventionally been viewed as challenging, is functional group effective and provides a wider variety of products in good to excellent yields.

中文翻译：

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吲哚糖半萜生物碱的高区域选择性氧化 Csp2-H 胺化反应：（+）-dioridamycin 的总合成


二聚体吲哚糖半萜类化合物在合成群落中引起了极大的兴趣，因为它们的生物活性潜力高于其单体同系物。生物合成学表明，夏霉素 A （2a） 可以在氧化条件下二聚化，形成更有效的全可能 N-N、C-N 和 C-C 二聚体。追求建立这些键的有效方法推动了合成化学的进步，导致了增强产生这些具有生物学意义的分子的能力的新策略和工具。迄今为止，奥利霉素 A 二聚体的合成和生物学评价仍未得到探索。在此，我们描述了一种合成设计，旨在实现二利霉素 （1a） 的简洁全合成和夏霉素 A （1b） 的 C-C 二聚体，在战略性地使用高价碘 （III） 来锻造分子内交叉胺化，导致吲哚糖半萜类五环核心在温和和原子经济的条件下。我们的研究揭示了 PhI（OAc）₂ 在吲哚半萜类化合物分子内 C-N 键的引入中的效用，这在传统上被认为是具有挑战性的，具有官能团有效，并提供了更广泛的产品，产量从好到极好。