Départment de Pharmacochimie Moléculaire, Univ. Grenoble Alpes, ICMG FR-2607, CNRS, UMR-5063, F-38041, Grenoble, France.
Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France.
Org Biomol Chem. 2023 Jan 25;21(4):817-822. doi: 10.1039/d2ob01723g.
A new approach to the synthesis of the (-)-205B alkaloid is described in this paper. This work is characterised by the development of an efficient chirality transfer through a silyl tethered intramolecular alkylation reaction, an unprecedented tandem highly selective iridium catalyzed partial reduction of lactam coupled with an acid promoted aza-Prins reaction, and an almost complete stereochemical control in Shenvi's radical hydrogen atom transfer on an exocyclic methylene. The second part of this work demonstrates the positive allosteric behavior of this natural alkaloid toward α7 nAChRs, in contrast to the reported inhibitory effect of the unnatural enantiomer.
本文描述了一种(-)-205B 生物碱的新合成方法。这项工作的特点是通过硅基 tethered 分子内烷基化反应实现高效的手性转移,这是前所未有的串联高选择性铱催化内酰胺部分还原与酸促进的氮杂-Prins 反应,以及在 Shenvi 的外消旋亚甲基自由基氢原子转移中几乎完全的立体化学控制。这项工作的第二部分证明了这种天然生物碱对α7 nAChRs 的正变构行为,与报道的非天然对映异构体的抑制作用形成对比。