Various 3,5-disubstituted-1,2,4-oxadiazoles are smoothly formed via copper-catalyzed cascade annulation of amidines and methylarenes. This tandem oxidation-amination-cyclization transformation represents a straightforward protocol to prepare 1,2,4-oxadiazoles from easily available starting materials, with...
A reaction involving an efficient NBS-mediated oxidative N‒O bond formation has been established for the synthesis of 1,2,4-oxadiazoles from readily accessible N-acyl amidines. The features of this synthetic method include simplicity of operation, mild reaction conditions, short reaction times, high yields, and eco-friendliness. The reaction also works well with crude N-acyl amidines obtained by amidation
Copper‐Catalyzed Three‐Component Cascade Reaction of Benzaldehyde with Benzylamine and Hydroxylamine or Aniline: Synthesis of 1,2,4‐Oxadiazoles and Quinazolines
作者:Chao Wang、Xiyan Rui、Dongjuan Si、Rupeng Dai、Yueyue Zhu、Hongmei Wen、Wei Li、Jian Liu
DOI:10.1002/adsc.202001535
日期:2021.6.8
The analogous three-component synthesis strategy for substituted 1,2,4-oxadiazole and quinazoline derivatives from readily available benzaldehyde, benzylamine and hydroxylamine or aniline has been developed. Both the cascade reaction sequences involves nucleophilic addition of C−N bond, introduction a halogen donor, nucleophilic substitution and Cu(II)-catalyzed aerobic oxidation. This synthesis methodology
Electrochemical synthesis of 1,2,4-oxadiazoles from amidoximes through dehydrogenative cyclization
作者:Chan Jiang、Mingfang Li、Leitao Xu、Yangjie Yi、Jiao Ye、Aixi Hu
DOI:10.1039/d1ob02040d
日期:——
through anodic oxidation was developed for the synthesis of 3,5-disubstituted 1,2,4-oxadiazoles from N-benzyl amidoximes. The transformation proceeds through 1.5-Hydrogen Atom Transfer (1,5-HAT) and intramolecular cyclization. The process features simple operation, mild conditions, broad substrate scope and high functional group compatibility, and provides a facile and practical way for the preparation of
Oxidative cyclization of amidoximes and thiohydroximic acids: A facile and efficient strategy for accessing 3,5-disubstituted 1,2,4-oxadiazoles and 1,4,2-oxathiazoles
作者:Jatin J. Lade、Bhausaheb N. Patil、Kamlesh S. Vadagaonkar、Atul C. Chaskar
DOI:10.1016/j.tetlet.2017.04.045
日期:2017.5
A facile and practical protocol has been developed for the synthesis of 3,5-disubstituted 1,2,4-oxadiazoles and 1,4,2-oxathiazoles through oxidative cyclization of amidoximes and thiohydroximic acids, respectively at room temperature. Use of mild reaction conditions, inexpensive reagents, broad substrate scope and good to excellent yield of the products are the salient features of this protocol.