Synthesis 2015; 47(13): 1877-1886
DOI: 10.1055/s-0034-1379906
paper
© Georg Thieme Verlag Stuttgart · New York

Catalyst-Free and Oxidant-Free Synthesis of 1,3,5-Trisubstituted Pyrazoles by Michael-Type Addition of Hydrazone sp2 Nitrogen Atoms to Enones

Authors

  • Chunyin Zhu*

    School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. of China   eMail: zhucycn@gmail.com
  • Benwei Bi

    School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. of China   eMail: zhucycn@gmail.com
  • Dewei Yao

    School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. of China   eMail: zhucycn@gmail.com
  • Qiu-Yun Chen

    School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. of China   eMail: zhucycn@gmail.com
  • Zhi-Bin Luo

    School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. of China   eMail: zhucycn@gmail.com
Weitere Informationen

Publikationsverlauf

Received: 28. Dezember 2014

Accepted after revision: 05. März 2015

Publikationsdatum:
31. März 2015 (online)


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Abstract

A new single-step approach to 1,3,5-trisubstituted pyrazoles from hydrazones and α,β-unsaturated keto esters has been developed. This catalyst- and oxidant-free transformation involves a Michael-type addition of the hydrazone sp2 nitrogen to the enone and a redox isomerization. The procedure has a wide substrate scope and shows good compatibility with both α-ester- and α-keto-substituted hydrazones.

Supporting Information