Copper-Catalyzed Alkynylation of In Situ-Generated Azoalkenes: An Umpolung Approach to Pyrazoles

Copper-Catalyzed Alkynylation of In Situ-Generated Azoalkenes: An Umpolung Approach to Pyrazoles Full article

Journal

Organic Letters
ISSN: 1523-7060 , E-ISSN: 1523-7052

Output data

Year: 2024, Volume: 26, Number: 33, Pages: 6999-7003 Pages count : 5 DOI: 10.1021/acs.orglett.4c02471

Authors

Kokuev Aleksandr O. ¹ , Sukhorukov Alexey Yu. ¹

Affiliations

1	N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospect 47, Moscow 119991, Russian Federation

A straightforward umpolung approach to regioselectively N-protected polysubstituted pyrazoles starting from aromatic α-halohydrazones and terminal alkynes has been developed. In this process, azoalkenes generated in situ from α-halohydrazones are involved in the Cu(I)-catalyzed Michael addition with alkynes to give α-alkynyl-substituted hydrazones that cyclize to give the target pyrazoles in 37–85% yield. The method employs readily available starting materials and features good functional group compatibility (nitro, sulfonyl, cyano, trimethylsilyl, and primary bromoalkyl groups, esters, and alcohols are tolerated) and scalability.

Kokuev A.O. , Sukhorukov A.Y.
Copper-Catalyzed Alkynylation of In Situ-Generated Azoalkenes: An Umpolung Approach to Pyrazoles
Organic Letters. 2024. V.26. N33. P.6999-7003. DOI: 10.1021/acs.orglett.4c02471 WOS Scopus OpenAlex

Web of science:	WOS:001287535100001
Scopus:	2-s2.0-85200924709
OpenAlex:	W4401413902

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