对丙烯基茴香醚的直接电氧化活化

Direct electro-oxidation of p-propenyl anisole

采用循环伏安法(CV)、恒电位电解法和计时电流法研究了对丙烯基茴香醚(p-PA)在乙腈-水混合溶液中的直接电氧化行为,考察了水的含量、扫描速度、温度、反应底物浓度、电解电位、电极等因素对p-PA中C═C电氧化活化的影响。实验结果表明,p-PA在乙腈-水混合溶液中的电氧化过程是不可逆的,且该过程受扩散步骤控制,扩散系数D=2.53×10^(-6) cm^2·s^(-1)。通过GC-MS检测,p-PA直接电氧化的主要产物为对甲氧基苯甲醛(p-MBA)。在一室型无隔膜电解槽中,以石墨棒为工作电极,25℃下,乙腈-水混合溶液中水的含量为20%时,反应底物几乎全部转化,p-MBA的产率可达93%。

Direct electro-oxidation ofp-propenyl anisole（p-PA） in acetonitrile aqueous solutions was studied by cyclic voltammetry （CV）, controlled potential electrolysis and chronoamperometry. The effect of water content, scan rate, temperature, reactant concentration, electrolysis potential and electrode on activation of C-C bond were studied. The results showed that electro-oxidation of p-PA in acetonitrile aqueous solutions was an irreversible process, which was mainly diffusion-controlled with the diffusion coefficient （D） of 2.53×10^-6 cm^2·s^-1 The major direct electro-oxidation product ofp-PA was p-methoxybenzaldehyde （p-MBA）. At 20% water content, the yield ofp-MBA could be improved to 93% and almost complete conversion of reactant on graphite rod electrode at 25℃ in an undivided electrolytic cell.