Substituent effects on the iodine-catalyzed thermal cyclization of 3,4-diphenylbuta-1,3-dienyl isocyanates: mechanistic studies

J Org Chem. 2011 Dec 2;76(23):9678-86. doi: 10.1021/jo2017247. Epub 2011 Oct 31.

Abstract

The thermal cyclization of 3,4-diphenylbuta-1,3-dienyl isocyanates 1, generated in situ from the corresponding azides, was investigated using iodine as a catalyst. Diphenylpyridinones 2, phenylnaphthalenes 3, and indenes 4 were produced via intramolecular ring closure. The nature of the substituents on the phenyl rings was found to be crucial to the distribution of cyclized products 2-4. The mechanism of the reaction is also discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Cyclization
  • Iodine / chemistry*
  • Isocyanates / chemical synthesis*
  • Isocyanates / chemistry
  • Molecular Structure
  • Temperature*

Substances

  • 3,4-diphenylbuta-1,3-dienyl isocyanate
  • Isocyanates
  • Iodine