KOt-Bu promoted homocoupling and decomposition of N′-aryl acylhydrazines: synthesis of unsymmetric N′,N′-diaryl acylhydrazines
作者:Wei-juan Wang、Ting Zhang、Li-jun Duan、Xue-jing Zhang、Ming Yan
DOI:10.1016/j.tet.2015.10.023
日期:2015.12
The KOt-Bu promoted homocoupling and decomposition of N′-aryl acylhydrazines has been achieved. The method allows for a novel and efficient synthesis of unsymmetric N′,N′-diaryl acylhydrazines under mild reaction conditions. The reaction probably proceeds via the generation of N′-centered acylhydrazine radicals and the subsequent homolytic aromatic substitution.
[3 + 2]-Cycloaddition of <i>in Situ</i> Generated Nitrile Imines and Acetylene for Assembling of 1,3-Disubstituted Pyrazoles with Quantitative Deuterium Labeling
作者:Vladimir V. Voronin、Maria S. Ledovskaya、Evgeniy G. Gordeev、Konstantin S. Rodygin、Valentine P. Ananikov
DOI:10.1021/acs.joc.8b00155
日期:2018.4.6
methodology for the preparation of 1,3-disubstituted pyrazoles from in situ generated nitrile imines and acetylene is reported. The reactions are performed in a simple two-chamber reactor. One part of the reactor is loaded with hydrazonoyl chloride precursors of active nitrile imine species and a base. The other part is used to generate acetylenefrom CaC2 and water. Partitioning of the reactants improves
A nickel-promoted cascadeannulation reaction for the facile synthesis of 3H-1,2,4-triazol-3-ones from readily available hydrazonoyl chlorides and sodium cyanate has been developed. The transformation occurs through a cascade nickel-promoted intermolecular nucleophilic addition–elimination process, intramolecular nucleophilic addition, and a hydrogen-transfer sequence. The method has been successfully
已经开发了镍促进的级联环化反应,用于从容易获得的酰肼基氯和氰酸钠容易地合成3 H -1,2,4-三唑-3-酮。通过级联镍促进的分子间亲核加成-消除过程,分子内亲核加成和氢转移序列进行转化。该方法已成功应用于血管紧张素II拮抗剂的核心骨架的构建。
Assembly of <i>N</i>,<i>N</i>-Disubstituted Hydrazines and 1-Aryl-1<i>H</i>-indazoles via Copper-Catalyzed Coupling Reactions
作者:Xiaodong Xiong、Yongwen Jiang、Dawei Ma
DOI:10.1021/ol300847v
日期:2012.5.18
CuI-catalyzed coupling of N-acyl-N′-substituted hydrazines with aryl iodides takes place at 60–90 °C to afford N-acyl-N′,N′-disubstituted hydrazines regioselectively and thereby gives a facile method for assembling N,N-diaryl hydrazines. N-Acyl-N′-substituted hydrazines can also react with 2-bromoarylcarbonylic compounds at 60–125 °C under the catalysis of CuI/4-hydroxy-l-proline to provide 1-aryl-1H-indazoles
Reagent/Substituent Switching Approach for the Synthesis of Substituted 1,3,4-Oxadiazole/1,3,4-Oxadiazoline and 1,2,4-Triazole Derivatives from N-Substituted Hydrazides
作者:Trimurtulu Kotipalli、Veerababurao Kavala、Ashok Konala、Donala Janreddy、Chu-Wei Kuo、Ching-Fa Yao
DOI:10.1002/adsc.201600274
日期:2016.8.18
A metal‐free method for the synthesis of substituted 1,3,4‐oxadiazole/1,3,4‐oxadiazoline and 1,2,4‐triazole derivatives from a common starting material via reagent/substituent switching is reported. In the presence of 2‐fluoropyridine/triflic anhydride, 1,3,4‐oxadiazole derivatives were exclusively formed from N′‐tert‐butylhydrazides and 1,3,4‐oxadiazoline derivatives were produced from N‐phenylhydrazides