☆ 4.4 Article

Intramolecular Cyclization of Vinyldiazoacetates as a Versatile Route to Substituted Pyrazoles

SYNLETT (2020)

Journal

SYNLETT

Volume 31, Issue 12, Pages 1158-1162

Publisher

GEORG THIEME VERLAG KG

DOI: 10.1055/s-0040-1707111

Keywords

pyrazoles; vinyldiazoacetates; vinyldiazo compounds; cyclization; electrocyclization

Categories

Chemistry, Organic

Funding

Carl-Zeiss-Stiftung
Friedrich-Schiller-Universitat Jena
Ernst Ludwig Ehrlich Foundation
State of Thuringia [2015 FGI0021]
European Regional Development Fund (ERDF)

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Abstract

Vinyldiazo compounds undergo a thermal electrocyclization to form pyrazoles in yields of up to 95%. The reactions are operationally simple, use readily available starting materials, require no intervention of a catalyst, and enable the synthesis of mono-, di- and tri-substituted pyrazoles. With the ability to produce highly substituted pyrazoles and the flexibility in installing various types of substituents, this method constitutes a new entry to this valuable heterocyclic scaffold and may be of interest to all branches of the chemical industry.

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