897-18-7Relevant academic research and scientific papers
Electrochemical Synthesis of 2,5-Disubstituted 1,3,4-Oxadiazoles from α-Keto Acids and Acylhydrazines Under Mild Conditions
Lu, Fangling,Gong, Fengping,Li, Liangsen,Zhang, Kan,Li, Zhen,Zhang, Xinwei,Yin, Ying,Wang, Ying,Gao, Ziwei,Zhang, Heng,Lei, Aiwen
supporting information, p. 3257 - 3260 (2020/05/25)
1,3,4-Oxadiazoles are a kind of useful heterocycles which can be frequently found in materials and bioactive molecules. In this study, intermolecular electrochemical cyclization between α-keto acids and acylhydrazines has been developed for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles with the yield up to 91 %. This transformation can be run under mild reaction conditions in the absence of external oxidant, base and transition metal catalyst. Both symmetrical and unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles could be prepared according to the careful choice of the substrate combination. Gram scale synthesis also illustrates the potential application of this protocol in large preparation.
Photocatalyzed facile synthesis of 2,5-diaryl 1,3,4-oxadiazoles with polyaniline-?g-C3N4-TiO2 composite under visible light
Wang, Liang,Wang, Yaoyao,Chen, Qun,He, Mingyang
supporting information, p. 1489 - 1492 (2018/03/13)
PANI (polyaniline)-g-C3N4-TiO2 composite was prepared and found to be efficient for the synthesis of 2,5-diaryl 1,3,4-oxadiazoles under visible light. This reaction involved decarboxylation and cyclization from α-keto acids with acylhydrazines, and a broad scope of substrates were tolerated to provide the desired products in moderate to good yields. Control experiments indicated that a radical pathway was involved in the present photocatalytic reaction and a synergistic effect may exist in the ternary composite. Moreover, this semiconductor photocatalyst could be readily recovered and showed good reusability with only slight decrease in the catalytic activity after six consecutive runs.
Iron(III)/TEMPO-Catalyzed Synthesis of 2,5-Disubstituted 1,3,4-Oxadiazoles by Oxidative Cyclization under Mild Conditions
Zhang, Guofu,Yu, Yidong,Zhao, Yiyong,Xie, Xiaoqiang,Ding, Chengrong
, p. 1373 - 1377 (2017/06/27)
A simple and efficient cationic Fe(III)/TEMPO-catalyzed oxidative cyclization of aroyl hydrazones has been developed for the synthesis of 2,5-disubstituted 1,3,4-oxadiazole derivatives. The reaction offers a broad scope, good functional-group tolerance, and high yields under mild conditions in the presence of O 2.
A process for preparing 2, 5 - disubstituted - 1, 3, 4 - oxadiazoles (by machine translation)
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Paragraph 0031; 0032; 0033; 0034; 0035; 0071-0075, (2017/07/19)
The invention provides a method for catalytic oxidative cyclization of formula (II) is shown in the 1, 3, 4 - oxadiazole method, said method comprising: in order to having a structure of formula (I) indicated by the formyl zong compound as a raw material, in order to air or oxygen atmosphere, in order to nitric acid the iron is catalyst, in order to 2, 2, 6, 6 - tetramethyl piperidine nitrogen oxides as initiator, under the action of the water absorbing agent, under the action of the water absorbing agent, in an organic solvent, for 25 - 60 °C lower reaction 3 - 12h, and the resulting reaction solution by the following formula (II) after treatment indicated by the 1, 3, 4 - oxadiazole compounds; the reaction of the invention speed, mild condition, easy operation, low cost, safe reaction, the whole process is friendly to the environment, pollution-free. (by machine translation)
One-pot cyclization/decarboxylation of α-keto acids and acylhydrazines for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles under transition-metal-free conditions
Gao, Peng,Wang, Juan,Bai, Zijing,Cheng, Hualei,Xiao, Jian,Lai, Mengnan,Yang, Desuo,Fan, Mingjin
supporting information, p. 4616 - 4619 (2016/09/23)
A one-pot KI/TBHP-mediated oxidative cyclization of α-keto acids with acylhydrazines was developed. A series of functional 2,5-disubstituted 1,3,4-oxadiazoles were synthesized through a tandem keto amine condensation followed by oxidative cyclization and decarboxylation reactions. This procedure was achieved under transition-metal-free conditions and showed advantages including readily available materials, mild reaction conditions and good group tolerance.
Palladium-catalyzed one-pot synthesis of diazoles via tert-butyl isocyanide insertion
Fan, Xiang-Yuan,Jiang, Xiao,Zhang, Ying,Chen, Zhen-Bang,Zhu, Yong-Ming
, p. 10402 - 10408 (2015/10/28)
An efficient one-pot palladium-catalyzed reaction for the synthesis of diazoles from readily available hydrazides and aryl halide via isocyanide insertion/cyclization sequence has been developed. This methodology efficiently constructs diazoles in good to excellent yields with the advantages of wide functional group tolerance and operational simplicity.
Palladium-Catalyzed Aminocarbonylation Reaction to Access 1,3,4-Oxadiazoles using Chloroform as the Carbon Monoxide Source
Li, Zhengyi,Wang, Liang
, p. 3469 - 3473 (2016/01/25)
A palladium-catalyzed aminocarbonylation reaction of aryl halides with chloroform and tetrazoles has been developed, where chloroform was employed as the carbon monoxide (CO) source in the presence of cesium hydroxide. The in situ generated N-acylated tetrazoles were unstable and easily decomposed to afford 2,5-disubstituted 1,3,4-oxadiazoles. A wide range of tetrazoles and aryl halides reacted smoothly under the optimized reaction conditions to give the corresponding products in moderate to good yields.
An Improved Synthesis of 2-Aryl- and 2-Alkenyl-1,3,4-oxadiazoles by Using Copper(II) Oxide Nanoparticles as a Catalyst 1
Salva Reddy,Raghavendar Reddy,Das, Biswanath
, p. 2831 - 2838 (2015/09/15)
2-Aryl- and 2-alkenyl-1,3,4-oxadiazoles were efficiently synthesized in high yields by treatment of 1,3,4-oxadiazoles with aryl or alkenyl halides, respectively, in the presence of copper(II) oxide nanoparticles as a catalyst. The reusability of the catalyst is an important advantage in relation to practical applications of this synthesis.
Organocatalytic Oxidative Amidation of Aldehydes with Tetrazoles to Construct 2,5-Diaryl 1,3,4-Oxadiazoles
Cao, Jing,Wang, Liang
supporting information, p. 1239 - 1243 (2015/11/27)
A practical and metal-free oxidative amidation of aldehydes with tetrazoles into 1,3,4-oxadiazoles has been developed by employing tetrabutylammonium iodide (TBAI) as catalyst and tert-butyl hydroperoxide (TBHP) as oxidant. A wide range of 2,5-disubstituted 1,3,4-oxadiazoles can be conveniently generated in moderate to good yields. Gram-scale reaction was also realized in this catalytic system..
One-Pot Synthesis of 2,5-Diaryl 1,3,4-Oxadiazoles via Di-tert-butyl Peroxide Promoted N-Acylation of Aryl Tetrazoles with Aldehydes
Wang, Liang,Cao, Jing,Chen, Qun,He, Mingyang
supporting information, p. 4743 - 4748 (2015/05/13)
A metal- and base-free protocol for one-pot synthesis of 2,5-diaryl 1,3,4-oxadiazoles via a radical-promoted cross-dehydrogenative coupling strategy was developed. This reaction involved the N-acylation of aryl tetrazoles with aryl aldehydes, followed by thermal rearrangement. A wide range of aryl tetrazoles and aryl aldehydes survived the reaction conditions to deliver the corresponding products in moderate to good yields. (Chemical Equation Presented).
