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Oxazolium Salts as Organocatalysts for the Umpolung of Aldehydes.

Venkata Krishna Rao GarapatiMichel Gravel
Published in: Organic letters (2018)
Oxazolium salts were successfully employed for the first time as organocatalysts for benzoin, Stetter, and redox esterification reactions. An N-mesityl oxazolium salt catalyzed homobenzoin reaction of aromatic, heteroaromatic, and aliphatic aldehydes delivered α-hydroxy ketones in high yields. This new type of catalyst proved remarkably effective for the Stetter reaction of challenging substrates such as β-alkyl-α,β-unsaturated ketones and electron-rich aromatic aldehydes in comparison to common thiazolium and triazolium salts.
Keyphrases
  • ionic liquid
  • room temperature
  • electron transfer
  • amino acid
  • visible light