Synthesis of Vinyl Sulfones from Aryl Methyl Ketones Under Sonochemical Conditions and Formation of Allyl Sulfones
作者:H. El Fakih、F. Pautet、D. Peters、H. Fillion、J. L. Luche
DOI:10.1080/00397919408010244
日期:1994.12
Abstract An efficient synthesis of vinyl sulfones 3a-o from aryl methyl ketones 2 bearing an electron withdrawing group and the phosphonic ester 1 under sonochemical conditions is reported. These compounds are generally obtained as an E/Z mixture. Formation of the allyl sulfones 4 is also observed.
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.