Department of Chemistry, University of Science and Technology of China, 230026, Hefei, China.
Institutes of Physical Science and Information Technology, Anhui University, 230601, Hefei, China.
Nat Commun. 2022 Mar 15;13(1):1344. doi: 10.1038/s41467-022-29059-0.
Despite that asymmetric stereodivergent synthesis has experienced great success to provide unusual processes for the creation of chirality complexity, concepts appliable to asymmetric stereodivergent catalysis are still limited. The dependence on the unusual capacity of each catalyst to precisely control the reactive site planar in the region poses unparalleled constraints on this field. Here, we first demonstrate that the chiral Cu-allenylidene species can participate in the stereodivergent propargylic alkylation of enals, in concert with chiral N-heterocyclic carbenes (NHCs). Thus, all four stereoisomers were obtained with excellent enantioselectivity and diastereoselectivity (up to >99% e.e. and >95:5 d.r.) from the same starting materials by simply altering chiral Cu-Pybox complex and NHC combinations. The rich chemistry workable in the products enables the structurally diverse synthesis of chiral functional molecules and holds great potential in alkaloid synthesis, as showcased by the preparation of the key building block to access (-)-perophoramidine.
尽管不对称立体发散合成在提供创造手性复杂性的不寻常过程方面取得了巨大成功，但适用于不对称立体发散催化的概念仍然有限。每个催化剂都需要依靠其不寻常的能力来精确控制反应部位在区域中的平面，这对手性领域构成了前所未有的限制。在这里，我们首先证明手性 Cu-烯丙基物种可以与手性 N-杂环卡宾 (NHC) 一起参与烯醛的立体发散丙炔基烷基化反应。因此，通过简单地改变手性 Cu-Pybox 配合物和 NHC 的组合，从相同的起始原料中以优异的对映选择性和非对映选择性（高达>99%ee 和>95:5d.r.）获得了所有四个立体异构体。产物中可进行的丰富化学变化使具有结构多样性的手性功能分子的合成成为可能，并且在手性生物碱合成中具有巨大的潜力，这一点通过制备获得(-)-perophoramidine 的关键构建块得到了展示。
