Direct Imine Acylation: A Versatile Method for the Synthesis of Nitrogen-Containing Heterocycles, Spirocycles and Natural Products

William P. Unsworth*, Richard J K Taylor

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Diverse nitrogen-containing heterocyclic compounds can be synthesised by the N-acylation of imines using functionalised carboxylic acids (Direct Imine Acylation, DIA). The carboxylic acids are activated in situ using the coupling agent propylphosphonic acid anhydride (T3P), before reacting with the imine coupling partner to generate N-acyl­iminium ions in situ, that can then be trapped by oxygen-, nitrogen-, sulfur- or carbon-based nucleophiles built into the carboxylic acid. This versatile, convergent method has been used to generate a wide range of products, including aromatic and aliphatic heterocycles, β-lactams, azaspirocycles and natural products. 1 Introduction 2 DIA in the Total Synthesis of ‘Upenamide 3 DIA with Benzoic Acid Derivatives 4 DIA with Aliphatic Carboxylic Acids 5 DIA in the Synthesis of β-Lactams 6 DIA in the Synthesis of Azaspirocycles 7 Mechanistic Studies 8 Conclusion

Original languageEnglish
Pages (from-to)2051-2064
Number of pages14
Issue number14
Early online date10 May 2016
Publication statusE-pub ahead of print - 10 May 2016

Bibliographical note

© 2016, Georg Thieme Verlag. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details


  • cavidine
  • evodiamine
  • N-acyliminium ions
  • N-heterocycles
  • natural products
  • spirocycles
  • ‘upenamide

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