Transition Metal‐free C−H Sulfonylation and Pyrazole Annulation Cascade for the Synthesis of 4‐Sulfonyl Pyrazoles
作者:Lihong Tian、Jie‐Ping Wan、Shouri Sheng
DOI:10.1002/cctc.202000244
日期:2020.5.7
A practical protocol for the synthesis of 4‐sulfonyl pyrazoles via the reactions of readily available N,N‐dimethyl enaminones and sulfonyl hydrazines has been developed via the catalysis of molecular iodine in the presence of TBHP and NaHCO3 at room temperature. The pyrazole products have been constructed via the tandem C(sp2)−H sulfonylation and a pyrazole annulation without employing any transition
p-Toluenesulphonic acid-promoted, I<sub>2</sub>-catalysed sulphenylation of pyrazolones with aryl sulphonyl hydrazides
作者:Xia Zhao、Lipeng Zhang、Tianjiao Li、Guiyan Liu、Haomeng Wang、Kui Lu
DOI:10.1039/c4cc05237d
日期:——
Aryl pyrazolone thioethers were synthesized via the I2-catalysed cross-coupling of pyrazolones with aryl sulphonyl hydrazides in the presence of p-toluenesulphonic acid, which has been proposed to promote the reaction by facilitating the decomposition of sulphonyl hydrazides.
Synthesis and potential anticonvulsant activity of new aryl sulfonyl semicarbazide derivatives
作者:Yousong Nie、Min Zhong、Zhiyuan Jiang、Jian Sun、Yangguang Gao、Fei Ding、Hang Li、Yongmin Zhang、Xianran He
DOI:10.1007/s00044-016-1582-2
日期:2016.7
In the present study on the development of newanticonvulsants, twelve new aryl sulfonyl semicarbazide derivatives were synthesized and tested for anticonvulsantactivity using maximal electroshock (MES), subcutaneous pentylenetetrazole screens. Their neurotoxicity was determined by the rotorod test. The most active compound 5i showed the MES-induced seizures with ED50 value of 7.3 mg/kg and TD50 value
Iodine promoted iodosulfonylation of alkynes with sulfonyl hydrazides in an aqueous medium: highly stereoselective synthesis of (<i>E</i>)-β-iodo vinylsulfones
作者:Yunlei Hou、Liangyu Zhu、Hao Hu、Shaowei Chen、Zefei Li、Yajing Liu、Ping Gong
DOI:10.1039/c8nj01145a
日期:——
metal-free sulfonylation reaction for the preparation of (E)-β-iodo vinylsulfones from alkynes with sulfonyl hydrazides and molecular iodine was efficiently developed under mild and environmentally benign conditions, in water without any ligand or catalyst. The reaction gave a range of structurally diverse β-iodo vinylsulfones with excellent E selectivities and high yields.
High Chemoselectivity in the Construction of Aryl Methyl Sulfones via an Unexpected C–S Bond Formation between Sulfonylhydrazides and Dimethyl Phosphite
作者:Chao Huang、Feixiang Cheng、Teng Liu、Shiwen Yu、Xiang Shen、Yixian Li、Jianjun Liu
DOI:10.1055/a-1581-2271
日期:2022.1
methyl sulfones via an unexpected C–S bond formation between sulfonylhydrazides and dimethylphosphite catalyzed by NaI under mild conditions has been established. This transformation provides an alternative and metal-free pathway to acquire various aryl methyl sulfones in good to excellent yields. Notably, dimethylphosphite was employed as a stable and readily available alkyl source.
已经建立了通过在温和条件下由 NaI 催化的磺酰肼和亚磷酸二甲酯之间意外形成 C-S 键形成芳基甲基砜的高度化学选择性途径。这种转化提供了一种替代的无金属途径,可以以良好到极好的收率获得各种芳基甲基砜。值得注意的是,亚磷酸二甲酯被用作稳定且容易获得的烷基源。