A simple and general preparation of vinylic sulfides, selenides and tellurides
作者:Claudio C. Silveira、Paulo Cesar S. Santos、Samuel R. Mendes、Antonio L. Braga
DOI:10.1016/j.jorganchem.2008.09.039
日期:2008.12
A general method for the synthesis of vinylic chalcogenides by nucleophilic and Ni-catalyzed vinylic substitution on vinylichalides by phenyl chalcogenolates is described. The reactions were regio and stereoselective for the nickel catalyzed substitution, and mixture of isomers was observed for some examples in the thermal process in DMF.
Mild, Efficient and Highly Stereoselective Synthesis of (<i>Z</i>)-Vinyl Chalcogenides from Vinyl Bromides Catalyzed by Copper(I) in Ionic Liquids Based on Amino Acids
作者:Weiliang Bao、Zhiming Wang、Hanjie Mo
DOI:10.1055/s-2006-958413
日期:2007.1
A method for the synthesis of(Z)-vinyl chalcogenides by the coupling of vinyl bromides with thiols or diphenyl diselenide using copper(I) salts as catalysts in ionic liquids based on amino acids is reported. The desired vinyl chalcogenides were obtained in good to excellent yields with retention of stereochemistry. The ionic liquids play multiple roles in the reaction: they act as solvent, base, and
unprecedented geminal olefinic dichalcogenation of alkenyl sulfonium salts with dichalcogenides ArYYAr (Y = S, Se, Te) is reported, providing various trisubstituted 1,1-dichalcogenalkenes [Ar1CH = C(YAr2)2] in a highly selective manner under mild and catalyst-free conditions. The key process involves the formation of two geminal olefinic C–Y bonds viasequential C–Y cross-coupling and C–H chalcogenation. A