Competition between isomerization and addition in the Sonication of Vinyl Sulfones in the presence of bromotrichloromethane
作者:Dietmar Peters、F�lix Pautet、Hamid El Fakih、Houda Fillion、Jean-Louis Luche
DOI:10.1002/prac.19953370178
日期:——
(E)- and (Z)-vinyl sulfones isomerise under ultrasound irradiation in carbon tetrachloride in the presence of bromoform or bromotrichloromethane to give an E/Z equilibrium mixture via bromine radicals. Furthermore, the bromine radicals formed add to the C=C double bond (presumably of the Z isomer) to form vic-dibromo compounds. In pure CBrCl3 this addition reaction reaches a 99% yield. In tetrahydrofurane/CBr4 (or CBrCl3) no isomerization is observed since the bromine radicals react probably with the THF. The addition is also favoured by highly efficient energy transmission.
(E)- 和 (Z)-炔二硫酸在碳二氯化碳中,在溴化(that) 或溴三氯甲烷的促进下,受超声波照射而发生互化反应,形成一种 E/Z 平衡混合物,这些混合物是由溴单质微粒形成的。在纯的 CBrCl3 中,加成反应达到了 99% 的产率。在四氢呋喃/ CBr4 (或 CBrCl3) 的情况下,没有互化反应发生,因为溴单质可能与四氢呋喃反应。加成反应也受到高效能量传递的促进作用。