Nitronate anion recognition and modulation of ambident reactivity by hydrogen-bonding receptors

Brian R. Linton, M. Scott Goodman, Andrew D. Hamilton

Research output: Contribution to journalArticle

Abstract

Nitronate anions were shown to form complexes in DMSO with hydrogen-bonding receptors such as 1,3-dimethylthiourea 1 (Ka = 120M-1) and bicyclic guanidinium2 (Ka = 3200M-1). A ditopic bis-thiourea exhibited increased association with substrates, that contained either two nitronates (Ka = 7000M-1) or a combination of nitronate and carboxylate (Ka = 1200M-1). Complexation of nitronate resulted in a change in the ambident reactivity during alkylation with p-nitrobenzyl bromide. The predominant reaction pathway was shifted from oxygen alkylation to carbon alkylation as receptor binding strength increased. Kinetic analysis indicated an overall inhibition of nitronate reactivity, and this suggests that greater suppression of the oxygen pathway allows carbon alkylation to predominate.

Original languageEnglish (US)
Pages (from-to)2449-2455
Number of pages7
JournalChemistry - A European Journal
Volume6
Issue number13
DOIs
StatePublished - Jul 3 2000

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Keywords

  • Ambident nucleophiles
  • Anions
  • Hydrogen bonds
  • Molecular recognition
  • Receptors

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

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