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Updated: Jun 11, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
A modular sydnone cycloaddition/Suzuki-Miyaura cross-coupling strategy to unsymmetrical 3,5-bis(hetero)aromatic
Thierry Delaunay1, Pierre Genix, Mazen Es-Sayed
1Institut de Chimie et Biochimie Moléculaires et Supramoléculaires (ICBMS, UMR 5246 du CNRS), ESCPE Lyon, Université Lyon 1, 43, Bd du 11 Novembre 1918, 69622 Villeurbanne, France.
Abstract:
The [3 + 2] dipolar cycloaddition of 4-halosydnones with 1-haloalkynes opens a straightforward access to 3,5-dihalopyrazoles, valuable scaffolds for the elaboration of unsymmetrically 3,5-substituted pyrazole derivatives via site-selective Pd-catalyzed cross-coupling reactions. For instance, the flexible introduction of different (hetero)aryl substituents at the C-5 and C-3 positions of the PMP-protected pyrazole nucleus was achieved in a one-pot operation via sequential reactions with various boronic acids.
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