Absolute Configurations and Stereochemical Inversion Mechanism of Epimeric Securinega Alkaloids from Flueggea suffruticosa
Absolute Configurations and Stereochemical Inversion Mechanism of Epimeric Securinega Alkaloids from Flueggea suffruticosa
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烟果差向异构叶底生物碱的绝对构型及立体化学反转机制
DOI：
10.1021/acs.orglett.0c01167
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发表时间：
2020
期刊：
影响因子：
5.2
通讯作者：
Ye Wen-Cai
中科院分区：
文献类型：
--
作者：
Wu Zhen-Long;Huang Xiao-Jun;Hu Li-Jun;Zhang Wei-Yan;Xie Qiu-Jie;Jiang Ren-Wang;Wang Ying;Ye Wen-Cai
从红花大果草（Flueggea suffruticosa）中分离得到3对含哌啶-2-基的一叶碱差向异构体（1-6），并对其结构进行了明确的表征。在每对差向异构体中观察到一个相互转化的C-2′差向异构化过程。以下综合性的实验和理论研究证明了一个不寻常的立体化学反转机制的N-取代的碳立体异构中心，这被证明是一个质子溶剂介导的过程，涉及串联的1，4-消除/1，4-加成作为关键步骤。
Three pairs ofSecurinegaalkaloid epimers with a piperidin-2-yl moiety (1–6) were isolated fromFlueggea suffruticosa, and their structures including absolute configurations were definitely characterized. An interconvertible C-2′ epimerization process within each pair of epimers was observed. The following comprehensive experimental and theoretical investigations demonstrated an unusual stereochemical inversion mechanism of an N-substituted carbon stereogenic center, which was evidenced to be a protic solvent mediated process involving a tandem 1,4-elimination/1,4-addition as the key step.