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Interceptive [4 + 1] Annulation of in Situ Generated 1,2-Diaza-1,3-dienes with Diazo Esters: Direct Access to Substituted Mono-, Bi-, and Tricyclic 4,5-Dihydropyrazoles

Orazio A. Attanasi, Lucia De Crescentini, Gianfranco Favi*, Fabio Mantellini, Serena Mantenuto and Simona Nicolini

*Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Via I Maggetti 24, 61029 Urbino, Italy, Email:

O. A. Attanasi, L. De Crescentini, G. Favi, F. Mantellini, S. Mantenuto, S. Nicolini, J. Org. Chem., 2014, 79, 8311-8338.

DOI: 10.1021/jo5016097 (free Supporting Information)

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In situ derived acyclic and cyclic 1,2-diaza-1,3-dienes (DDs) undergo an interceptive [4 + 1] annulation with diazo esters (DEs) in the presence of inexpensive copper(II) chloride to yield mono-, bi-, and tricyclic 4,5-dihydropyrazole-5-carboxylic acid derivatives.

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Key Words


ID: J42-Y2014