20672-18-8Relevant academic research and scientific papers
Synthesis of 2-Substituted 1,2,3-Triazoles via an Intramolecular N–N Bond Formation
Chen, Cheng-yi,Lu, Xiaowei,Holland, Mareike C.,Lv, Shichang,Ji, Xuebao,Liu, Wei,Liu, Jie,Depre, Dominique,Westerduin, Pieter
supporting information, p. 548 - 551 (2019/12/24)
An efficient synthesis of 2-aryl 1,2,3-triazoles based on an intramolecular N–N bond formation is described. Selective activation of bis-hydrazone at the dimethylamino hydrazone group with MeI forms a mono-hydrazonium species. Treatment of the hydrazonium
Iodine-Catalyzed Regioselective Oxidative Cyclization of Aldehyde Hydrazones with Electron-Deficient Olefins for the Synthesis of Mefenpyr-Diethyl
Deng, Yun-Xia,Lin, Hao-Peng,Wang, Wen-Kang,Zhao, Sheng-Yin,Zheng, Jian,Zhu, Jia-Nan
, (2019/08/26)
A regioselective synthesis of polysubstituted dihydropyrazoles and pyrazoles through an iodine-catalyzed oxidative cyclization strategy of aldehyde hydrazones with electron-deficient olefins is described. The protocol adopts very mild reaction conditions and provides desirable yields. The reaction is supposed to proceed via a cascade C-H functionalization, C-N bond formation, and oxidation sequential processes. The overall simplicity and regioselectivity of the catalytic system make this approach a valuable and step-economical tool to construct a C-C bond for the synthesis of Mefenpyr-Diethyl.
Pyrrolo[3,4-c]pyrazole Synthesis via Copper(?) Chloride-Catalyzed Oxidative Coupling of Hydrazones to Maleimides
Zhu, Jia-Nan,Wang, Wen-Kang,Jin, Ze-Hui,Wang, Qian-Kun,Zhao, Sheng-Yin
supporting information, p. 5046 - 5050 (2019/09/03)
A variety of pyrrolo[3,4-c]pyrazole derivatives from readily available aldehyde hydrazones and maleimides via direct oxidative coupling under radical cascade reaction have been reported. This method offers satisfactory chemical yields and good functional
Room-temperature oxidative Suzuki coupling reaction of 1,2,3-triazole N-oxides
Liu, Wei,Yu, Yanyan,Fan, Boyi,Kuang, Chunxiang
supporting information, p. 2969 - 2971 (2017/07/10)
This study develops a new efficient pathway for synthesis of 2,4-disubstituted 1,2,3-triazoles through regioselective direct arylation between 2-aryl-1,2,3-triazole N-oxides and Ar-B(OH)2. The reaction proceeds smoothly at room temperature and exhibits good yield and high C5 position selectivity. The possible pathway of oxidative Suzuki coupling is also discussed. This simple methodology can be used to construct 2,4-disubstituted 1,2,3-triazole moiety.
Molybdenum-Catalyzed Deoxygenation of Heteroaromatic N-Oxides and Hydroxides using Pinacol as Reducing Agent
Rubio-Presa, Rubén,Fernández-Rodríguez, Manuel A.,Pedrosa, María R.,Arnáiz, Francisco J.,Sanz, Roberto
supporting information, p. 1752 - 1757 (2017/05/22)
A molybdenum-catalyzed deoxygenation of pyridine N-oxides and N-hydroxybenzotriazoles, as well as other azole N-oxides, has been developed using pinacol as an environmentally friendly oxo-acceptor. The only by-products are acetone and water making the process a convenient alternative to established protocols in terms of waste generation. The reaction is highly chemoselective and a variety of functional groups are tolerated. The processes are usually very clean allowing the isolation of the pure deoxygenated products after a simple extraction in most cases. (Figure presented.).
Iridium(III)-Catalyzed Direct C-H Sulfonamidation of 2-Aryl-1,2,3-triazole N-Oxides with Sulfonyl Azides
Zhu, Bingfeng,Cui, Xiuling,Pi, Chao,Chen, Dong,Wu, Yangjie
supporting information, p. 326 - 332 (2016/02/14)
We have developed a method for the direct sulfonamidation of 2-aryl-1,2,3-triazole N-oxides using sulfonyl azides as the amino source to release molecular nitrogen as the sole by-product. This protocol exhibits excellent functional group tolerance and proceeds efficiently under external oxidant-free conditions. Various 2-(2-sulfonamidoaryl)-1,2,3-triazoles were prepared in up to 97% yields for 25 examples with excellent regioselectivity.
Silver(I)-Catalyzed Tandem Sigamatropic Rearrangement/1,3-H Shift/6π Aza-electrocyclization of N-Propargylic Hydrazones: A Mild Synthetic Route to 1,6-Dihydropyridazines
Ding, Zong-Cang,Ju, Lu-Chuan,Yang, Ying,An, Xiao-Ming,Zhou, Yun-Bing,Li, Ren-Hao,Tang, Hai-Tao,Ding, Cheng-Ke,Zhan, Zhuang-Ping
, p. 3936 - 3941 (2016/05/24)
A highly efficient AgOTf catalyzed [3,3] sigmatropic rearrangement/1,3-H shift/6' aza-electrocyclization cascade reaction of N-propargylic hydrazones has been developed. This method provides a new mild synthetic route to various polysubstituted 1,6-dihydr
Site-selective direct arylation of 1,2,3-triazole N-oxides
Liu, Wei,Li, Yahui,Wang, Yue,Kuang, Chunxiang
supporting information, p. 5272 - 5275 (2013/09/02)
An efficient route for the synthesis of 2,4-disubstituted 1,2,3-triazoles by the regioselective direct arylation of 2-aryl-1,2,3-triazole N-oxides with Ar-X [X = Br, I and B(OH)2] is demonstrated. The reaction proceeds through Pd-catalyzed C-H bond activation, and the influence of the aryl halides on the reactivity is investigated. An efficient route for the synthesis of 2,4-disubstituted 1,2,3-triazoles by the regioselective direct arylation of 2-aryl-1,2,3-triazole N-oxides with Ar-X [X = Br, I and B(OH)2] is demonstrated. The reaction proceeds through Pd-catalyzed C-H bond activation, and the influence of the aryl halides on the reactivity is investigated. Copyright
Electrophilic and Nucleophilic Substitution in the Triazole N-Oxides and N-Methoxytriazolium Salts: Preparation of Substituted 1,2,3-Triazoles
Begtrup, Mikael,Holm, John
, p. 503 - 513 (2007/10/02)
2-Phenyltriazole 1-oxides are activated at C-5 towards both electrophilic and nucleophilic attack.The N-oxides can be selectively halogenated and, in turn, the halogen replaced by strong nucleophiles.On subsequent deoxygenation, the N-oxides yield halogeno-, methylthio-, and methoxy-triazoles.Methylation produces N-methoxytriazolium salts in which H-5 can be replaced by weak nucleophiles, e.g. fluoride ions.Thus fluoro-, chloro-, hydroxy-, alkoxy-, acyloxy-, amino-, substituted amino-, azido-, nitro-, mercapto-, alkylthio-, acylthio-, and cyano-substituents can be introduced in the triazole nucleus.Alternatively deprotonated N-methoxytriazolium salts react with electrophiles producing substituted triazole N-oxides.The reactions of triazole N-oxides with hydrogen chloride to give chlorotriazoles, and with acetyl chloride to give acetoxytriazoles, are explained.
