An Electrochemical Way to Generate Amphiphiles from Hydrazones for the Synthesis of 1,2,4‐Triazole Scaffold Cyclic Compounds
作者:Wangyu Li、Mingteng Xiong、Xiao Liang、Dungai Wang、Heping Zhu、Yuanjiang Pan
DOI:10.1002/open.202100268
日期:2022.1
Electrochemically forming amphiphiles, hydrazones were chosen as bifunctional reagents analogous to 1,3-dicarbonyl compounds. About 70 1,2,4-triazoles have been prepared in moderate to high yields, testifying to the validity and practicality of this strategy. This approach can also be conducted as a one-pot reaction without intermediate treatments for the construction of 1,2,4-triazoles by using phenylhydrazines
Regioselective Synthesis of 4-Nitro- or 4-Chloro-Tetrasubstituted Pyrazoles from Hydrazones and β-Halo-β-nitrostyrenes
作者:Xiaohu Deng、Jimmy T. Liang、Neelakandha S. Mani
DOI:10.1002/ejoc.201301294
日期:2014.1
We report an acid-catalyzed cycloaddition reaction of hydrazones with β-bromo- or β-chloro-β-nitrostyrenes for the regioselectivesynthesis of 4-nitro- or 4-chloro-tetrasubstitutedpyrazoles. Arising from a common 4-halo-4-nitropyrazolidine intermediate, the identity of the pyrazole product formed is dependent on the relative leaving group abilities of the halo and nitro substituents.
A DABCO‐catalyzed double cascade cycloaddition reaction of diverse maleimides with bisarylhydrazones has been developed for the synthesis of a variety of synthetically challenging pyrazolo[5,1‐c][1,2,4]triazole derivatives. Dioxygen gas is employed as the sole oxidant in this transformation. It proceeds with high step‐ and atom‐efficiency and shows a broad substrate scope and functional group tolerance
已经开发了DABCO催化的各种马来酰亚胺与双芳基hydr酮的双级联双环加成反应,用于合成多种具有合成挑战性的吡唑并[5,1– c ] [1,2,4]三唑衍生物。在该转化中,将氧气用作唯一的氧化剂。它具有较高的步长和原子效率,并显示出广泛的底物范围和官能团耐受性,使其成为制备完全取代的吡唑并[5,1– c ] [1,2,4]三唑衍生物的实用方法。