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.
Palladium-catalyzed homocoupling reactions of organic tellurides
作者:Yoshiaki Nishibayashi、Chan Sik Cho、Kouichi Ohe、Sakae Uemura
DOI:10.1016/s0022-328x(96)06561-8
日期:1996.12
Organic tellurides containing a styryl moiety react in acetonitrile to give the corresponding homocoupling products, 1,3-dienes, with moderate to quantitative yields in the presence of a catalytic amount of Pd(OAc)(2) together with AgOAc at 25 degrees C. In contrast, such homocoupling reactions hardly occur with diaryl, alkyl aryl, dialkyl, and alkynyl aryl tellurides, even at reflux temperature and in the presence of a stoichiometric amount of palladium salt, in disagreement with reported results. The result of cross-over experiments suggests that this homocoupling reaction occurs between an alkenyl telluride and an alkenylpalladium species, the latter being formed via the migration of an alkenyl moiety from Te to Pd (transmetallation).
OHE, KOUCHI;TAKAHASHI, HIDETAKA;UEMURA, SAKAE;SUGITA, NOBUYUKI, J. ORG. CHEM., 52,(1987) N 22, 4859-4863