TiCl<sub>4</sub> mediated facile synthesis of 1,3,4-oxadiazoles and 1,3,4-thiadiazoles
作者:Lin Zhang、Yu Yu、Qiang Tang、Jianyong Yuan、Dongzhi Ran、Binghua Tian、Tao Pan、Zongjie Gan
DOI:10.1080/00397911.2019.1700521
日期:2020.2.1
Abstract An efficient method for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles and 1,3,4-thiadiazoles has been developed. Various hydrazides or thionyl hydrazides readily react with DMA derivatives in the presence of TiCl4 as a catalyst to afford the desired products. This protocol provides a simple and economical procedure that affords the target products with good yields and wide substrate
Metal-Free Synthesis of 1,3,4-Oxadiazoles from N′-(Arylmethyl)hydrazides or 1-(Arylmethyl)-2-(arylmethylene)hydrazines
作者:Zhenhua Shang、Sheng Tan、Qianqian Chu
DOI:10.1055/s-0034-1379974
日期:——
tert-butyl ether. Aldehyde N-acylhydrazones and aldazines were initially generated in situ as intermediates. An efficient and versatile metal-free synthesis of 1,3,4-oxadiazolesfrom N′-(arylmethyl)hydrazides or 1-(arylmethyl)-2-(arylmethylene)hydrazines through oxidative dehydrogenation is reported. A range of 2,5-disubstituted1,3,4-oxadiazoles were prepared by treating N′-(arylmethyl)hydrazides with (diacetoxyiodo)benzene
Oxidative Cyclization of Aromatic Aldehyde<i>N</i>‐Acylhydrazones by bis(Trifluoroacetoxy)iodobenzene
作者:Zhenhua Shang
DOI:10.1080/00397910600773650
日期:2006.10
Abstract Aromatic aldehyde N‐acylhydrazones were oxidized into 2,5‐disubstituted 1,3,4‐oxadiazoles with bis(trifluoroacetoxy)iodobenzene in CHCl3 or DMSO at room temperature in good to excellent yields.
Novel procedure for the synthesis of 1,3,4-oxadiazoles from 1,2-diacylhydrazines using polymer-supported Burgess reagent under microwave conditions
作者:Christopher T. Brain、Jane M. Paul、Yvonne Loong、Paul J. Oakley
DOI:10.1016/s0040-4039(99)00382-2
日期:1999.4
A novel and efficient means of effecting the cyclodehydration of 1,2-diacylhydrazines to provide 1,3,4-oxadiazoles is reported. Polymer supported Burgess reagent was utilised in combination with single-mode microwave heating.
Cyclopentano[c]-s-triazoles were synthesized by intramolecular ringtransformation starting from y-keto-l,3,4-oxadiazoles 5 and 9. The required functionality for this intramolecular reaction was established by (i) the reaction of lithiated 2-methyl-l,3,4-oxadiazole 4 with the methyl enol ether of α-bromo ketones followed by hydrolysis; (ii) reductive amination of γ-ketones 5 and 9 to further reorganized