Dienophile twisting and substituent effects influence reaction rates of intramolecular Diels-Alder cycloadditions: A DFT study

Kelli S. Khuong, Chris M. Beaudry, Dirk Trauner, K. N. Houk

Research output: Contribution to journalArticle

Abstract

Intramolecular cycloadditions of 5-vinyl-1,3-cyclohexadienes were studied with B3LYP/6-31G(d) density functional calculations. The one-atom tether dictates that the Z substituent becomes exo and the E substituent becomes endo in the TS. The geometry of the cycloaddition TS is typical of a pericyclic transformation except unusual twisting of the dienophile places the endo substituent in a relatively steric-free position and the exo substituent in a highly crowded position. The experimental rate differences between isomeric pairs of vinylcyclohexadienes can be explained by comparing reactant destabilization when a bulky group occupies the Z position of the starting alkene and transition state stabilization when a bulky group is endo in the cycloaddition TS.

Original languageEnglish (US)
Pages (from-to)3688-3689
Number of pages2
JournalJournal of the American Chemical Society
Volume127
Issue number11
DOIs
StatePublished - Mar 23 2005

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ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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