Deprotection of Oximes, Phenylhydrazones, Semicarbazones and Thiosemicarbazones to the Corresponding Carbonyl Compounds Using Cetyltrimethylammonium Peroxodisulfate as a New and Selective Oxidizing Agent
Cetyltrimethylammonium peroxodisulfate (CTA)2S2O8 was quantitatively prepared and used for the deprotection of oximes, phenylhydrazones, semicarbazones and thiosemicarbazones to the corresponding carbonylcompounds in acetonitrile. Its agent is more efficient and has advantages over similar reagents in terms of the amount of oxidant, short reaction time, simple work up, and high yield.
Ligand-free Cu(<scp>ii</scp>)-mediated aerobic oxidations of aldehyde hydrazones leading to N,N′-diacylhydrazines and 1,3,4-oxadiazoles
作者:Lei Liu、Suliu Feng
DOI:10.1039/c7ob00042a
日期:——
A Cu(II)-mediated synthesis of N,N′-diacylhydrazines and 1,3,4-oxadiazoles from aldehyde hydrazones has been developed. This is the first time that the synthesis of N,N′-diacylhydrazines and 1,3,4-oxadiazoles using N,N-dimethylamides as the acylation reagent and O2 in air as the oxidation reagent is reported. These reactions offered several advantages including simple workups, ligand-free inexpensive
cyclization protocol employing cobalt nitrate and 1,2‐dichloroethane to produce substituted 1H‐1,2,4‐triazoles. Notably, 1,2‐dichloroethane serves both the solvent and a hydrogen source for transfer hydrogenation. This methodology works under mild conditions, providing a direct approach for the synthesis of 1H‐1,2,4‐triazoles.
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
A novel sequential [3+2] annulation reaction has been developed using prop-2-ynylsulfonium salts and hydrazonyl chlorides, affording a series of pyrazoles with functional motifs that can be post modified in the preparation of various drugs or drug candidates. Further transformation and gram-scale operations could also be achieved efficiently.