Palladium-catalyzed 2-arylation of pyrroles

J Org Chem. 2009 Dec 18;74(24):9517-20. doi: 10.1021/jo902124c.

Abstract

A methodology that affords N-alkyl-2-arylpyrroles and N-aryl-2-arylpyrroles via direct coupling from aryl iodides has been developed. After examining various reaction parameters: solvent, ratio of reagents, catalyst, base and additives the optimal conditions for the condensation were identified. Two crucial factors, (a) anhydrous DMSO as solvent and (b) 5 M excess of pyrrole counterpart, were found to strongly influence the reaction outcome. The conditions identified (PdCl(2)(PPh(3))(2), AgOAc, anhyd DMSO, KF, 100 degrees C, 5 h) resulted in the formation of 2-arylpyrroles in 14-80% yield. Furthermore, the synthesis is compatible with electron-withdrawing and electron-donating groups on the aryl moiety.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Dimethyl Sulfoxide / chemistry
  • Hydrocarbons, Cyclic / chemical synthesis
  • Hydrocarbons, Cyclic / chemistry*
  • Hydrocarbons, Iodinated / chemistry
  • Models, Chemical
  • Organometallic Compounds / chemistry*
  • Palladium / chemistry*
  • Pyrroles / chemical synthesis
  • Pyrroles / chemistry*
  • Silver / chemistry
  • Solvents / chemistry
  • Temperature
  • Time Factors

Substances

  • Hydrocarbons, Cyclic
  • Hydrocarbons, Iodinated
  • Organometallic Compounds
  • Pyrroles
  • Solvents
  • Silver
  • Palladium
  • Dimethyl Sulfoxide