An Iron-Catalyzed Route to Dewar 1,3,5-triphosphabenzene and Subsequent Reactivity

Adam N. Barrett, Martin Diefenbach, Mary F. Mahon, Vera Krewald, Ruth L. Webster

Research output: Contribution to journalArticlepeer-review

1 Citation (SciVal)


The application of an alkyne cyclotrimerization regime with an [Fe(salen)] 2-μ-oxo (1) catalyst to triphenylmethylphosphaalkyne (2) yields gram-scale quantities of 2,4,6-tris(triphenylmethyl)-Dewar-1,3,5-triphosphabenzene (3). Bulky lithium salt LiHMDS facilitates a rearrangement of 3 to the 1,3,5-triphosphabenzene valence isomer (3′), which subsequently undergoes an intriguing phosphorus migration reaction to form the ring-contracted species (3′′). Density functional theory calculations provide a plausible mechanism for this rearrangement. Given the stability of 3, a diverse array of unprecedented transformations was investigated. We report novel crystallographically characterized products of successful nucleophilic/electrophilic addition and protonation/oxidation reactions.

Original languageEnglish
Article numbere202208663
JournalAngewandte Chemie International Edition
Issue number37
Early online date9 Aug 2022
Publication statusPublished - 12 Sept 2022

Bibliographical note

Engineering and Physical Sciences Research Council (Grant number(s): EP/P024254/1; Grant recipient(s): Ruth L. Webster, Adam N. Barrett);
Leverhulme Trust (Grant number(s): RPG-2020-3


  • Electrophilic Addition
  • Iron
  • Nucleophilic Addition
  • Phosphorus Heterocycles
  • Reaction Mechanisms

ASJC Scopus subject areas

  • Catalysis
  • General Chemistry


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