Furans Accessed through Visible-Light-Mediated Oxidative [3+2] Cycloaddition of Enols and Alkynes
作者:Ailong Shao、Xu Luo、Chien-Wei Chiang、Meng Gao、Aiwen Lei
DOI:10.1002/chem.201704519
日期:2017.12.19
Visible‐light‐mediated formation of furans though direct oxidative [3+2] cycloaddition of 1,3‐diones and alkynes is described. This protocol provides a simple and mild route to poly‐substituted furans in moderate‐to‐good yields. Preliminary mechanistic studies suggest that this reaction likely follows a radical addition/cyclization pathway.
A conceptually new strategy has been described for the mild, practical, and environmentally friendly preparation of naphthols and furans using a visible-light promoted photoredox neutral approach. These reactions between accessible electron-deficient bromides and commercially available alkynes could be carried out at room temperature in good-to-excellent chemical yields without any external stoichiometric oxidants.