Iron(0) nanoparticles mediated direct conversion of aryl/heteroaryl amines to chalcogenides via in situ diazotization
作者:Subir Panja、Pintu Maity、Debasish Kundu、Brindaban C. Ranu
DOI:10.1016/j.tetlet.2017.07.070
日期:2017.8
A simple procedure for the synthesis of organo-chalcogenides has been developed by the reaction of aryl/heteroaryl amines with di-aryl/heteroaryl dichalcogenides in the presence of tBuONO and Fe(0) nanoparticles. The reaction proceeds via in situ diazotization followed by chalcogenation. A series of functionalized diaryl/arylheteroaryl/diheteroaryl/aryl-alkyl selenides, sulfides and tellurides have
Metal-free radical thiolations mediated by very weak bases
作者:Denis Koziakov、Michal Majek、Axel Jacobi von Wangelin
DOI:10.1039/c6ob02276f
日期:——
Aromatic thioethers and analogous heavier chalcogenides were prepared by reaction of arene-diazonium salts with disulfides in the presence of the cheap and weak base NaOAc. The mild and practical reaction conditions (equimolar reagents, DMSO, r.t., 8 h) tolerate various functional groups (e.g. Br, Cl, NO2, CO2R, OH, SCF3, furans). Mechanistic studies indicate the operation of a radical aromatic substitution
Microwave-assisted reaction of aryl diazonium fluoroborate and diaryl dichalcogenides in dimethyl carbonate: a general procedure for the synthesis of unsymmetrical diaryl chalcogenides
作者:Debasish Kundu、Sabir Ahammed、Brindaban C. Ranu
DOI:10.1039/c2gc35328h
日期:——
A convenient, general and efficient procedure for the synthesis of unsymmetrical diaryl chalcogenides has been developed by the reaction of aryl diazonium fluoroborates and diaryl dichalcogenides in the presence of zinc dust in dimethyl carbonate under microwave irradiation. The reactions of a wide range of substituted aryl diazonium fluoroborates and diaryl dichalcogenides have been addressed. The
substitution (SH2) reaction between the aryl radical and diaryl ditelluride. Aryl radicals are generated from arylhydrazines in air and captured by diaryl ditellurides, resulting in a selective formation of unsymmetrical diaryl tellurides with high yields. The electronic effects of the substituents on both arylhydrazines and diaryl ditellurides on the SH2 reaction of tellurium are also discussed in detail.
When heated in hexamethylphosphoric triamide at 80–90°C, preferably in the presence of copper(I) iodide, moderately activated iodoarenes undergo nucleophilic attack by benzenetellurolate ion, giving the corresponding unsymmetrical diaryl tellurides in fair to good yields.