Palladium on carbon-catalyzed synthesis of 2- and 2,3-substituted indoles under heterogeneous conditions

Org Biomol Chem. 2010 Jul 21;8(14):3338-42. doi: 10.1039/c004939e. Epub 2010 Jun 4.

Abstract

A mild, efficient and LiCl-free synthetic method for indole derivatives based on the heteroannulation of alkynes with 2-iodoanilines was achieved using palladium on carbon (Pd/C) and NaOAc in heated NMP. The N-tosyl protection of 2-iodoaniline expedited the reaction progress, while other protecting groups, such as tert-butoxycarbonyl, acetyl, and benzyloxycarbonyl groups, underwent deprotection under the present conditions. A variety of di- and monosubstituted alkynes could effectively react with N-tosyl-2-iodoaniline to give the corresponding indoles in good to high yields.

MeSH terms

  • Alkynes / chemistry
  • Aniline Compounds / chemistry
  • Carbon / chemistry*
  • Catalysis
  • Indoles / chemical synthesis*
  • Indoles / chemistry*
  • Lithium Chloride / chemistry
  • Palladium / chemistry*

Substances

  • Alkynes
  • Aniline Compounds
  • Indoles
  • Palladium
  • Carbon
  • Lithium Chloride
  • aniline