在此,成功开发了四取代氧杂二烯和烯丙基硫叶立德的高效、底物导向的发散[2 + 3]/[2 + 1]环化。在精确的环化调控下,以高度立体选择性和经济的方式合成了一系列功能化的双螺环戊烷和双螺环丙烷衍生物(产率高达95%,>20:1 dr或>20:1 E / Z )。该方案具有条件温和、高化学、区域和非对映选择性以及广泛的底物兼容性等优点。此外,通过放大制备和一系列利用原位生成的硫叶立德的三组分反应评估了该方案的合成实用性。
Effective and diastereoselective preparation of dispiro[cyclopent-3′-ene]bisoxindoles <i>via</i> novel [3 + 2] annulation of isoindigos and MBH carbonates
作者:Hong-Xia Ren、Lin Peng、Xiang-Jia Song、Li-Guo Liao、Ying Zou、Fang Tian、Li-Xin Wang
DOI:10.1039/c7ob03009f
日期:——
A novel and diastereoselective [3 + 2] annulation of isoindigos and Morita–Baylis–Hillman carbonates has been developed for the highly efficient and one-step preparation of highly steric dispiro[cyclopent-3′-ene]bisoxindoles with two all-carbon quaternary spirocenters and three adjacent cycles in excellent yields (up to >99%) and diastereoselectivities (up to >20 : 1) under mild conditions within a
Phosphine‐Catalyzed (3+2) Annulation of Isoindigos with Allenes: Enantioselective Formation of Two Vicinal Quaternary Stereogenic Centers
作者:Wai‐Lun Chan、Xiaodong Tang、Fuhao Zhang、Glenn Quek、Guang‐Jian Mei、Yixin Lu
DOI:10.1002/anie.201900758
日期:2019.5.6
Construction of contiguous all‐carbon quaternary stereogenic centers is a long‐standing challenge in synthetic organic chemistry. In this report, a phosphine‐catalyzed enantioselective (3+2) annulation reaction between allenes and isoindigos, containing either two identical or different oxindole moieties, is introduced as a powerful strategy for the construction of spirocyclic bisindoline alkaloid