Copper-catalyzed synthesis of benzoxazoles via a regioselective C-H functionalization/C-O bond formation under an air atmosphere

J Org Chem. 2009 Jun 5;74(11):4272-7. doi: 10.1021/jo900513z.

Abstract

An efficient method for the synthesis of functionalized benzoxazoles is described that involves a copper(II)-catalyzed regioselective C-H functionalization/C-O bond formation protocol. The use of dichlorobenzene as a solvent at 160 degrees C allows the use of air as the terminal oxidant in the catalytic synthesis of benzoxazoles in a process that has high functional group tolerance. The presence of a directing group at the meta position markedly improves the reaction efficacy and a variety of 7-substituted benzoxazoles are selectively produced under mild reaction conditions. The mechanism of the reaction is also discussed in this report.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air
  • Benzoxazoles / chemical synthesis*
  • Catalysis
  • Copper
  • Oxygen / chemistry

Substances

  • Benzoxazoles
  • Copper
  • Oxygen