Stereoselective C(2)-vinylation of 1-substituted imidazoles with 3-phenyl-2-propynenitrile

J Org Chem. 2008 Nov 21;73(22):9155-7. doi: 10.1021/jo801240x. Epub 2008 Oct 17.

Abstract

First examples of direct vinylation of 1-substituted imidazoles at the 2-position of the imidazole nucleus are described. 1-Substituted imidazoles 1a-e are C(2)-vinylated with 3-phenyl-2-propynenitrile (2) at room temperature without catalyst and solvent to afford 3-(1-organyl-1H-imidazol-2-yl)-3-phenyl-2-propenenitriles 3a-e, mainly (c.a. 95%) as (Z)-isomers, in 56-88% yield. The reaction is likely to involve the zwitterionic intermediates, which prototropically isomerizes to imidazole carbene and eventually undergoes the selective 3,2-shift of the functionalized vinyl substituent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylene / analogs & derivatives*
  • Acetylene / chemistry
  • Ethylenes / chemistry*
  • Imidazoles / chemistry*
  • Nitriles / chemistry*
  • Stereoisomerism
  • Substrate Specificity

Substances

  • 3-phenyl-2-propynenitrile
  • Ethylenes
  • Imidazoles
  • Nitriles
  • ethylene
  • Acetylene