Cu-catalyzed reaction of 1,2-dihalobenzenes with 1,3-cyclohexanediones for the synthesis of 3,4-dihydrodibenzo[b,d]furan-1(2H)-ones

J Org Chem. 2012 Sep 21;77(18):7793-803. doi: 10.1021/jo3014275. Epub 2012 Sep 4.

Abstract

The Cu(I)-catalyzed reaction of 1-bromo-2-iodobenzenes and other 1,2-dihalobenzenes with 1,3-cyclohexanediones in DMF at 130 °C using Cs(2)CO(3) as a base and pivalic acid as an additive selectively delivers 3,4-dihydrodibenzo[b,d]furan-1(2H)-ones with yields ranging from 47 to 83%. The highly regioselective domino process is based on an intermolecular Ullmann-type C-arylation followed by an intramolecular Ullmann-type O-arylation. Substituted products are accessible by employing substituted 1-bromo-2-iodobenzenes and substituted 1,3-cyclohexanediones as substrates. Reaction with an acyclic 1,3-diketone yields the corresponding benzo[b]furan.

MeSH terms

  • Benzofurans / chemical synthesis*
  • Benzofurans / chemistry*
  • Catalysis
  • Copper / chemistry*
  • Cyclohexanes / chemistry*
  • Hydrocarbons, Halogenated / chemistry*
  • Iodobenzenes / chemistry*
  • Ketones / chemistry*
  • Molecular Structure
  • Stereoisomerism

Substances

  • Benzofurans
  • Cyclohexanes
  • Hydrocarbons, Halogenated
  • Iodobenzenes
  • Ketones
  • Copper