Cu(I)-Catalyzed (4+1) Tandem Annulation of Terminal Alkynes with 2-(Tosylmethyl)phenols: Access to 2,3-Disubstituted Benzofurans and Mechanism Insights

The Journal of Organic Chemistry 2026

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Authors: Xu Yan, Wenbo Zhang, Li Li, Jinxing Jiang, Yaqin Cui, Yi Luo, Yanzhi Liu, Peng Wang, Kun Yuan, Pan‐Lin Shao, Chun‐An Fan
DOI: 10.1021/acs.joc.6c00215
Cited by: 1
References: 69

Abstract

An efficient copper-catalyzed (4+1) tandem annulation has been established for the rapid construction of 2,3-disubstituted benzofurans. This method converts terminal alkynes and 2-(tosylmethyl)phenols using a dual-base system, proceeding via the in situ formation of ortho -quinone methides and alkynyl-copper(I) species. Combined density functional theory calculations and control experiments elucidate a mechanism proceeding through 1,4-conjugate addition, intramolecular cyclization, and base-promoted aromatization. This transformation not only provides a novel and efficient route to functionalized benzofuran motifs but also enriches the chemistry of alkynes and o -quinone methides in organic synthesis.

Fields of Study & Subjects

Synthesis of Indole Derivatives Catalytic C–H Functionalization Methods Catalytic Alkyne Reactions

Publication details

Journal / source
The Journal of Organic Chemistry
Publisher
American Chemical Society (ACS)
Volume
91
Issue
26
Pages
9224–9230
Publication date
18 June 2026
Language
EN