Amidine dications as superelectrophiles

Michael J Corr, Mark D Roydhouse, Kirsty F Gibson, Sheng-Ze Zhou, Alan R Kennedy, John A Murphy

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

2-Dimethylalkylammonium pyridinium and 2-dimethylalkylammonium pyrimidinium ditriflate salts are very powerful methylating agents toward phosphorus (triphenylphosphine) and nitrogen (triethylamine) nucleophiles. In competition experiments with triethylamine as nucleophile, these N-methyl disalts are more reactive methylating agents than dimethyl sulfate. Reaction of the pyridinium dications with water as an oxygen nucleophile leads to attack at the 2-position of the heteroaromatic ring and displacement of an ammonium group; 2-hydroxypyridinium compounds are formed in the first instance, which are easily converted to 2-pyridones. Extending the scope of the reactions, a tricationic 2,6-bis(dimethylalkylammonium) pyridinium salt has also been prepared and characterized and its reactivity as a methylating agent assessed in comparison with that of the dications.
Original languageEnglish
Pages (from-to)17980-17985
Number of pages6
JournalJournal of the American Chemical Society
Volume131
Issue number49
DOIs
Publication statusPublished - Nov 2009

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Keywords

  • methylating agents
  • triethylamine
  • oxygen nucleophile

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