Electrocatalytic three-component synthesis of 4-halopyrazoles with sodium halide as the halogen source
作者:Jin-Yang Chen、Hong-Xia Li、Si-Yu Mu、Hai-Yang Song、Zhi-Lin Wu、Tian-Bao Yang、Jun Jiang、Wei-Min He
DOI:10.1039/d2ob01612e
日期:——
synthesis of 4-chloro/bromo/iodopyrazoles from hydrazines, acetylacetones and sodiumhalidesunder chemical oxidant- and external electrolyte-free conditions has been developed. Sodiumhalides played a dual role as a halogenation reagent and a supporting electrolyte. Mechanism studies revealed that the bromination reaction proceeded via an ionic pathway, whereas both chlorination and iodination proceeded
A novel, cheap copper(II) fluoride-mediated N-arylation of heterocycles with halothiophenes is described. The yield of the pyrazolylthiophene strongly depends on the nature of the initial thiophene. The molecular structure of 3,5-dimethyl-1-(5'-methyl-[2,2']bithienyl-5-yl)-1H-pyrazole was studied by X-ray diffraction. (C) 2010 Elsevier Ltd. All rights reserved.
TBAX/Oxone‐Mediated Halogenation of Pyrazoles and Other Heterocycles: An Entry to Important Cross‐Coupling Reactions
作者:Jaspreet Kour、Pratiksha Khajuria、Alpa Sharma、Sanghapal D. Sawant
DOI:10.1002/asia.202200778
日期:2022.11.16
A facile green approach has been established for halogenation of pyrazoles and different heterocycles via a microwave-mediated protocol using TBAX/Oxone in EtOH. Applications and extension of the method have been demonstrated by presenting various coupling reactions of halogenated pyrazoles.