Formal (3 + 4)-Annulation of Propargylic <i>p</i>-Quinone Methides with 2-Indolylmethanols: Synthesis of Polysubstituted Indole-Fused Oxepines
Zong‐Wang Qiu, Bao Qiong Li, Hong‐Fu Liu, Zhi‐Qiang Zhu, Han‐Peng Pan, Na Feng, Ai‐Jun Ma, Jin‐Bao Peng, Xiang‐Zhi Zhang
Abstract
A novel Brønsted acid catalyzed 1,8-addition mediated (3 + 4)-annulation of in situ generated propargylic p-quinone methides with 2-indolylmethanols is described. This method provides a convenient and mild approach to structurally interesting and synthetically important polysubstituted indole-fused oxepines in high yields. Moreover, 2-indolylmethanols as four-atom synthons in the (3 + 4)-annulations under Brønsted acid conditions have been explored for the first time.
Topics & Concepts
AnnulationSynthonIndole testQuinoneBrønsted–Lowry acid–base theoryChemistryCombinatorial chemistryStereochemistryOrganic chemistryCatalysisSynthesis of Indole DerivativesSulfur-Based Synthesis TechniquesChemical Synthesis and Reactions