28710-62-5Relevant articles and documents
Oxone-DMSO Triggered Methylene Insertion and C(sp2)-C(sp3)-H-C(sp2) Bond Formation to Access Functional Bis-Heterocycles
Bharatam, Prasad V.,Dubey, Gurudutt,Hussain, Yaseen,Kour, Jaspreet,Sahoo, Subash C.,Sawant, Sanghapal D.,Venkateswarlu, Vunnam,Verma, Praveen K.
supporting information, p. 4951 - 4962 (2020/05/08)
Metal-free insertion of a methylene group was achieved for the construction of a new C(sp2)-C(sp3)-H-C(sp2) bond in order to prepare novel bis-heterocyclic scaffolds. The complete mechanistic investigations included experimental study and DFT calculations, and various symmetric and unsymmetric bis-pyrazoles as well as other pyrazole-based bis-heterocyclic molecules were prepared in moderate to high yields. Further modification of the bridged methylene group in the unsymmetric pyrazoles generated a chiral center to extend the scope of this method.
Cycloisomerization of acetylenic oximes and hydrazones under gold catalysis: Synthesis and cytotoxic evaluation of isoxazoles and pyrazoles
Jeyaveeran,Praveen, Chandrasekar,Arun,M Prince,Perumal
, p. 73 - 83 (2016/02/09)
The synthesis of substituted isoxazoles and pyrazoles through a general cycloisomerization methodology has been reported. The capability of gold(III) chloride to promote cycloisomerization of both α, β-acetylenic oximes and α, β-acetylenic hydrazones is t
Synthesis of pyrazoles via electrophilic cyclization
Zora, Metin,Kivrak, Arif,Yazici, Ceyda
experimental part, p. 6726 - 6742 (2011/10/09)
Electrophilic cyclizations of α,β-alkynic hydrazones by molecular iodine were investigated for the synthesis of 4-iodopyrazoles. α,β-Alkynic hydrazones were readily prepared by the reactions of hydrazines with propargyl aldehydes and ketones. When treated with molecular iodine in the presence of sodium bicarbonate, α,β-alkynic hydrazones underwent electrophilic cyclization to afford 4-iodopyrazoles in good to high yields. Iodocyclization was general for a wide range of α,β-alkynic hydrazones and tolerated the presence of aliphatic, aromatic, heteroaromatic, and ferrocenyl moieties with electron-withdrawing and electron-donating substituents.
