Palladium-catalyzed indolization of N-aroylbenzotriazoles with disubstituted alkynes

Org Lett. 2009 Mar 5;11(5):1055-8. doi: 10.1021/ol900113f.

Abstract

The palladium-catalyzed denitrogenative indolization of N-aroylbenzotriazoles 1 and internal alkynes 2 produced the corresponding polysubstituted indoles 3 in good to high yields. For example, the reaction of 5,6-dimethyl-1-[4-(trifluoromethyl)benzoyl]benzotriazole (1j) with 6-dodecyne (2a), 4-octyne (2b), and diphenylacetylene (2f) in the presence of 10 mol % of Pd(PPh(3))(4) without solvent at 130 degrees C gave the corresponding indoles 3i, 3l, and 3p in 74, 71, and 41% yields, respectively. In the present reaction, the aroylbenzotriazole acts as a synthetic equivalent of a 2-haloanilide in Larock's indole synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes / chemistry*
  • Catalysis
  • Indoles / chemical synthesis*
  • Indoles / chemistry
  • Molecular Structure
  • Palladium / chemistry*
  • Triazoles / chemistry*

Substances

  • Alkynes
  • Indoles
  • Triazoles
  • Palladium