The reaction of ethyl α-bromocinnamates with tetrabutyl ammonium fluoride（TBAF） was influenced largely by the position of the substituent at the phenyl ring.While the substrates without an ortho substituent at the ...The reaction of ethyl α-bromocinnamates with tetrabutyl ammonium fluoride（TBAF） was influenced largely by the position of the substituent at the phenyl ring.While the substrates without an ortho substituent at the phenyl ring were transformed to the corresponding β-fluoro ethyl cinnamates under the reaction conditions,the presence of an ortho substituent only resulted in the formation of ethyl 3-phenylpropiolate derivatives.The reaction of ethyl 2-bromo-3-（4-methoxyphenyl） acrylate also failed to deliver the hydrofluorination product due to the electron-donating effect of the methoxy group.展开更多
A novel tetrabutyl ammonium bromide(TBAB) modified Wacker-type catalyst system supported on various supports has been investigated in the gas-phase oxidative carbonylation of methanol and CO for dimethyl carbonate(DMC...A novel tetrabutyl ammonium bromide(TBAB) modified Wacker-type catalyst system supported on various supports has been investigated in the gas-phase oxidative carbonylation of methanol and CO for dimethyl carbonate(DMC) synthesis. It is demonstrated that the SiO 2 supported Wacker-type catalysts have shown the best catalytic performance for DMC synthesis in terms of the activity and selectivity.展开更多
文摘The reaction of ethyl α-bromocinnamates with tetrabutyl ammonium fluoride（TBAF） was influenced largely by the position of the substituent at the phenyl ring.While the substrates without an ortho substituent at the phenyl ring were transformed to the corresponding β-fluoro ethyl cinnamates under the reaction conditions,the presence of an ortho substituent only resulted in the formation of ethyl 3-phenylpropiolate derivatives.The reaction of ethyl 2-bromo-3-（4-methoxyphenyl） acrylate also failed to deliver the hydrofluorination product due to the electron-donating effect of the methoxy group.
文摘A novel tetrabutyl ammonium bromide(TBAB) modified Wacker-type catalyst system supported on various supports has been investigated in the gas-phase oxidative carbonylation of methanol and CO for dimethyl carbonate(DMC) synthesis. It is demonstrated that the SiO 2 supported Wacker-type catalysts have shown the best catalytic performance for DMC synthesis in terms of the activity and selectivity.
