Facile synthesis of novel amino acid-like building blocks by N-alkylation of heterocyclic carboxylates with N-Boc-3-iodoazetidine

  • Monika IškauskienėEmail author
  • Greta Ragaitė
  • Frank A. Sløk
  • Algirdas Šačkus
Original Article


An efficient protocol providing easy access to highly functionalized heterocyclic compounds as novel organic building blocks was developed by coupling alkyl pyrazole-, indazole- and indolecarboxylates with N-Boc-3-iodoazetidine. The synthesized compounds are representatives of constrained non-chiral synthetic azole carboxylates in their N-Boc protected ester forms. Diversification of the prepared heterocyclic building blocks was achieved via application of palladium-catalyzed Suzuki–Miyaura cross-coupling reactions. In total, 34 building blocks were obtained to form a highly diversified small molecule collection. The structure of the novel heterocyclic compounds was investigated and verified by advanced NMR spectroscopy methods.

Graphic abstract


Heterocyclic amino acids Pyrazole Indazole Indole Building blocks 



This work has been accomplished with financial support provided by Vipergen ApS company (Copenhagen, Denmark).


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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Monika Iškauskienė
    • 1
    • 2
    Email author
  • Greta Ragaitė
    • 2
  • Frank A. Sløk
    • 3
  • Algirdas Šačkus
    • 1
    • 2
  1. 1.Department of Organic ChemistryKaunas University of TechnologyKaunasLithuania
  2. 2.Institute of Synthetic ChemistryKaunas University of TechnologyKaunasLithuania
  3. 3.Vipergen ApSCopenhagen VDenmark

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