Synlett
DOI: 10.1055/a-2705-9249
Letter
Published as part of the Special Issue dedicated to Prof. S. Chandrasekaran on his 80th birthday

I2-Catalyzed Access to Bis(pyrazolo[1,5-a]pyrimidinyl)sulfanes and Sulfenylated Pyrazolo[1,5-a]pyrimidines via C–H Functionalization

Autoren

  • Tathagata Choudhuri

    Department of Chemistry, University of Kalyani, Kalyani, India (Ringgold ID: RIN30132)
  • Papiya Sikdar

    Department of Chemistry, University of Kalyani, Kalyani, India (Ringgold ID: RIN30132)
  • Suvam Paul

    Department of Chemistry, University of Kalyani, Kalyani, India (Ringgold ID: RIN30132)
  • Sourav Das

    Department of Chemistry, University of Kalyani, Kalyani, India (Ringgold ID: RIN30132)
  • Avik Kumar Bagdi

    Department of Chemistry, University of Kalyani, Kalyani, India (Ringgold ID: RIN30132)

Gefördert durch: Department of Science, Technology and Biotechnology (DSTBT), West Bengal, India GO no. 324(Sanc.)/STBT-11012(25)/13/2024-ST SEC
Gefördert durch: Science and Engineering Research Board EEQ/2018/000498
Funding Information A.K.B. acknowledges the Department of Science, Technology and Biotechnology (DSTBT), West Bengal, India (GO no. 324(Sanc.)/STBT-11012(25)/13/2024-ST SEC), ANRF, DST (File no. EEQ/2018/000498), and the University of Kalyani (PRG) for financial support.


Graphical Abstract

Dedication

This article is dedicated to Prof. S. Chandrasekaran on the occasion of his 80th birthday.

Abstract

We have demonstrated a new route to bis(pyrazolo[1,5-a]pyrimidinyl)sulfanes from pyrazolo[1,5-a]pyrimidines through I2-catalyzed C–H functionalization employing thiourea as the sulfur source. 3-Iodopyrazolo[1,5-a]pyrimidines acted as the active intermediates for this radical C–H sulfenylation. This I2-catalyzed C–H sulfenylation has been extended toward the synthesis of sulfenylated pyrazolo[1,5-a]pyrimidines using sulfonyl hydrazides as sulfenylating agents. Various bis(pyrazolo[1,5-a]pyrimidinyl)sulfanes and sulfenylated pyrazolo[1,5-a]pyrimidines have been synthesized using these simple protocols. The use of easily accessible and bench-stable reactants and reagents, metal-free catalysis, broad substrate scopes, and practicality are the attractive features of this strategy. Moreover, the usefulness of thiourea as a sulfur source in the synthesis of bis(2-phenylimidazo[1,2-a]pyridin-3-yl)sulfane and bis(6-phenylimidazo[2,1-b]thiazol-5-yl)sulfane derivatives has been demonstrated.



Publikationsverlauf

Eingereicht: 18. Juli 2025

Angenommen nach Revision: 02. September 2025

Accepted Manuscript online:
19. September 2025

Artikel online veröffentlicht:
05. November 2025

© 2025. Thieme. All rights reserved.

Georg Thieme Verlag KG
Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

 
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