title: A modular sydnone cycloaddition/Suzuki-Miyaura cross-coupling strategy to unsymmetrical 3,5-bis(hetero)aromatic pyrazoles.
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.
authors.affiliation: Institut 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.
authors.forename: Thierry
authors.initials: T
authors.lastname: Delaunay
authors.forename: Pierre
authors.initials: P
authors.lastname: Genix
authors.forename: Mazen
authors.initials: M
authors.lastname: Es-Sayed
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Vors
authors.forename: Nuno
authors.initials: N
authors.lastname: Monteiro
authors.forename: Geneviève
authors.initials: G
authors.lastname: Balme
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D001897:Boronic Acids / Q000737:chemistry*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D006846:Hydrocarbons, Halogenated / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D013558:Sydnones / Q000737:chemistry*
chemical_list: D000480:Alkynes; D001897:Boronic Acids; D006846:Hydrocarbons, Halogenated; D011720:Pyrazoles; D013558:Sydnones; D010165:Palladium