A double ionic mechanism for the Chapman-like rearrangement of imino-ethers to N-alkylmides, in the solid state or in the melt. Theoretical and experimental evidence
摘要:
以 5-甲氧基-2-芳基-1,3,4-恶二唑为模型,研究表明亚氨基醚到 N-烷基酰胺的热重排是通过双离子机制进行的;在固态和熔体中进行的动力学测量给出了表观活化能,支持 ab initio 计算的活化焓。
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.
An unusually fast Chapman-like thermal rearrangement in the solid state
作者:Mich�le Dessolin、Michel Golfier
DOI:10.1039/c39860000038
日期:——
Some 5-methoxy-2-aryl-1,3,4-oxadiazoles undergo a 1,3 O-to-N thermalrearrangement of the methyl group, which takes place unusually easily, and much faster in the solidstate than in the melt.
Electrochemically promoted annulation of aldehydes and carbazates: access to 2-alkoxy/aryloxy-5-substituted 1,3,4-oxadiazole and 1,3,4-oxadiazol-2(3<i>H</i>)-one derivatives
作者:Hongjun Li、Dong Tang、Zafar Iqbal、Yaya Wan、Rui Jiang、Zhixiang Yang、Jinhui Yang
DOI:10.1039/d2nj04113h
日期:——
The strategy is oxidant-free and transition-metal free, offering the electrolyte-free completion of the reaction at roomtemperature. A possible mechanism has been proposed based on control-experiment results and literature reports. The practical utility of this approach is highlighted via the brief synthesis of 5-(4-chloro-3-(trifluoromethyl)phenyl)-1,3,4-oxadiazol-2(3H)-one, which is a potent inhibitor