Copper(II)-catalyzed direct dehydrative alkynylation of 2 H-chromene hemiketals with terminal alkynes to 2,2-disubstituted 2-alkynylated 2 H-chromenes

Org Biomol Chem. 2022 May 11;20(18):3785-3789. doi: 10.1039/d2ob00481j.

Abstract

The first copper-catalyzed direct dehydrative alkynylation of 2H-chromene hemiketals with terminal alkynes has been uncovered. The use of cheap and readily available CuCl2 as the catalyst allowed the preparation of various 2,2-disubstituted 2-alkynylated 2H-chromenes in moderate to good yields, which compensates for the limitation of the current methods only suited for the synthesis of 2-monosubsituted 2-alkynylated 2H-chromenes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes*
  • Benzopyrans
  • Catalysis
  • Copper*

Substances

  • 5,7-dimethoxy-2-methyl-2H-benzopyran
  • Alkynes
  • Benzopyrans
  • Copper