Electrophilic cyclization of (Z)-selenoenynes: synthesis and reactivity of 3-iodoselenophenes

J Org Chem. 2007 Aug 31;72(18):6726-34. doi: 10.1021/jo070835t. Epub 2007 Aug 10.

Abstract

We present here our results of the electrophilic cyclization reaction of (Z)-selenoenynes with different electrophiles such as I(2), ICl, PhSeBr, and PhSeCl. The cyclization reaction proceeded cleanly under mild reaction conditions, and 3-substituted selenophenes were formed in moderate to excellent yields. We observed that the nature of solvent and structure of (Z)-selenoenyne were important to the cyclization reaction. In addition, the obtained 3-iodoselenophenes were readily transformed to more complex products using a metal-halogen exchange reaction with n-BuLi and trapping the intermediate formed with aldehydes, furnishing the desired secondary alcohols in good yields. Conversely, using the palladium or copper catalyzed cross-coupling reactions with terminal alkynes or alkyl alcohols, we were able to convert 3-iodoselenophene to Sonogashira or Ullmann type products, respectively, in good yields.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehydes / chemistry
  • Cyclization
  • Electrons*
  • Iodine / chemistry*
  • Lithium / chemistry
  • Molecular Structure
  • Organoselenium Compounds / chemical synthesis*
  • Organoselenium Compounds / chemistry

Substances

  • Aldehydes
  • Organoselenium Compounds
  • Iodine
  • Lithium