Visible-Light-Induced C(sp2)-C(sp3) Coupling Reaction for the Regioselective Synthesis of 3-Functionalized Coumarins

J Org Chem. 2021 Jul 16;86(14):9552-9562. doi: 10.1021/acs.joc.1c00848. Epub 2021 Jun 30.

Abstract

A photocatalysis strategy for the regioselective synthesis of 3-functionalized coumarins is reported. With visible light irradiation, a direct and regioselective C(sp2)-C(sp3) coupling reaction of 3-(2-hydroxyphenyl)acrylates with ethers or thioethers occurs by using Ru(bpy)3Cl2·6H2O as a photocatalyst and TBHP as an oxidant. The cascade process involves alkenylation of the C(sp3)-H bond of ethers and lactonization, furnishing 3-alkylated coumarins as the final products. This approach is characterized by a broad substrate scope, mild reaction conditions, and simplified operation. The synthesis of 3-alkylated coumarins could be realized by a one-pot procedure, starting from commercially available salicylaldehyde.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Coumarins*
  • Ethers
  • Light*
  • Oxidants

Substances

  • Coumarins
  • Ethers
  • Oxidants