Role of cations and confinement in asymmetric photochemistry: Enantio- and diastereo-selective photocyclization of tropolone derivatives within zeolites

Abraham Joy, Lakshmi S. Kaanumalle, V. Ramamurthy

Research output: Contribution to journalArticle

23 Scopus citations

Abstract

Asymmetric induction in photochemical reactions has been explored using the photochemistry of tropolones as a model. Three approaches have been examined: chiral inductor, chiral auxiliary and [chiral inductor + chiral auxiliary]. All three methods gave excellent asymmetric induction in zeolite and very little or zero induction in solution. Results presented on tropolones clearly illustrate the remarkable influence that a confined space studded with cations can have on asymmetric induction. Tropolone derivatives, upon irradiation undergo 4π-electron electrocyclization to yield a bicyclic product and a rearranged product. Enantiomeric excess up to 68% has been achieved in the cyclized product. In systems where a chiral inductor has been covalently linked, diastereomeric excess as high as 88% has been achieved within a zeolite while the same system in solution gave 10%.

Original languageEnglish (US)
Pages (from-to)3045-3053
Number of pages9
JournalOrganic and Biomolecular Chemistry
Volume3
Issue number16
DOIs
StatePublished - Aug 21 2005

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry

Cite this