摘要/Abstract

采用循环伏安法（CV）和恒电流电解法（CCE）研究了对甲氧基苯甲醇（p-MeOC₆H₄CH₂OH）电化学氧化氰化合成相应芳腈化合物.考察了水的体积分数、硫酸浓度、电解温度、电极材料、电流密度和溶剂等因素对该电化学氧化氰化行为的影响.结果显示，以四丁基高氯酸铵（Bu₄NClO₄）为电解质，羟胺（HAM）为氮源，在含0.15 mol·L^-1 H₂SO₄及30%水的DMSO体系中，电流密度为10 mA/cm²条件下恒温60℃电解8 h，对甲氧基苯腈（p-MeOBN）的收率为90%.通过对反应底物普适性研究，发现含不同对位和邻位取代基的芳香伯醇均可通过电氧化氰化反应有效转化为相应的腈（61%~92%），并提出了该电氧化氰化反应的可能机理.本工作提出了一种在一室型无隔膜电解槽中，以原位生成醛的方式，无需加入额外的催化剂，通过阴阳两极协同反应的成对电化学合成腈类化合物的方法.
关键词: 芳香伯醇, 芳腈化合物, 直接电氧化, 成对电合成
The electro-oxidation cyanation of p-methoxybenzyl alcohol (p-MeOC₆H₄CH₂OH) to prepare aryl nitriles was studied by using cyclic voltammetry (CV) and constant current electrolysis (CCE). The effects of the volume ratio of H₂O, concentration of H₂SO₄, temperature, electrode materials, current density and solvents on the electro-chemical reaction were studied. The results showed that the yield of p-methoxylbenzonitrile (p-MeOBN) was 90% in 0.15 mol·L^-1 H₂SO₄ and 30% H₂O-DMSO solution at 60℃ and 10 mA/cm² of current density when tetrabutylammonium perchlorate (Bu₄NClO₄) was used as electrolyte. The CCE of aromatic benzyl alcohols with different p-and o-substituted analogs was investigated under the optimized reaction conditions, and the yields toward formation of the corresponding aryl nitriles were 61%~92%. A plausible mechanism for the electro-oxidation cyanation procedure was proposed. A novel paired electrochemical method for the synthesis of aryl nitriles from aromatic benzyl alcohols with hydroxylamine (HAM) as "N" source and aldehyde in situ in undivided electrochemical cell was successfully developed.
Key words: aromatic benzyl alcohols, aryl nitriles, direct electro-oxidation, paired electro-synthesis


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