Superacid-catalyzed reactions of olefinic pyrazines: an example of anti-Markovnikov addition involving superelectrophiles

Org Lett. 2005 Jun 9;7(12):2505-8. doi: 10.1021/ol050900q.

Abstract

[reaction: see text] Olefinic pyrazines are found to react with benzene in CF3SO3H and give anti-Markovnikov-type addition products. We propose that this is caused by two effects: destabilization of the carbocationic intermediates that would lead to Markovnikov-type products and the generation of a considerable amount of positive charge at the terminal carbon of the olefinic groups. This suggests that acid-catalyzed addition reactions can give anti-Markovnikov-type products when a multiply charged (i.e., superelectrophilic) group is adjacent to the olefinic site.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alkenes / chemistry
  • Benzene / chemistry
  • Catalysis
  • Electrochemistry
  • Indicators and Reagents
  • Molecular Structure
  • Pyrazines / chemistry*

Substances

  • Alkenes
  • Indicators and Reagents
  • Pyrazines
  • Benzene