有机媒质作用下芳香醛的间接电合成

Indirect Electro-oxidation Synthesis of Aromatic Aldehyde Under Organic Mediators

合成了含硝基的芳基咪唑(M)、三苯胺(P)和咔唑(C)3种有机媒质,通过循环伏安法(CV)测试了这3种有机媒质的电化学性能,发现不同的有机框架对媒质的氧化还原电位和电化学可逆性有很大的影响。在室温下通过CV和恒电位电解考察了P和C对对甲氧基甲苯(p-MT)的电催化氧化性能,结果显示:在1 mmol/L P作用下,加入10%(体积分数,以总体积计)H2O,1.2 V下,p-MT电化学氧化成对甲氧基苯甲醛(p-MBA)的产率可达83%。而对氧化电位较高的对甲氧基苯甲醇(p-MBz OH)电催化氧化成p-MBA,P也表现出很好电催化活性和选择性,在室温下,1.3 V时,p-MBA的产率达90%。通过P和C分别对p-MT和p-MBzOH选择性电氧化为p-MBA的电催化性能对比,结果显示:氧化还原电位较低的P适合于具有较低氧化电位的p-MT,而氧化还原电位较高的C更适合于具有较高氧化电位的p-MBz OH。

Three kinds of nitro-containing organic mediators including arylimid.azole (M),triphenylamine (P)and carbazole (C)frameworks were synthesized and their electrochemical properties were characterized using cyclic voltammetry (CV).The oxidation-reduction potentials and electrochemical reversibility of the organic mediators were greatly effected by their frameworks.The electro-catalytic oxidation activities of compounds P and C for p-methoxytoluene (p-MT)were investigated by CV and controlled potential electrolysis at room temperature.The results showed that when the water volume fraction was 10% of the total volume,p-MT could convert into p-methoxybenzaldehyde (p-MBA)with a yield of 83% in the presence of 1mmol/L compound P at 1.2V.The electro-catalytic activities of compounds P and C for p-methoxybenzyl alcohol (p-MBzOH)were also investigated.Compound P showed excellent electrocatalytic activity and selectivity for p-MBzOH,the yield ofp-MBA reached 90% through electro-oxidation at room temperature and at 1.3V.Compared the activity of P and C on the electro-oxidation ofp-MT and p-MBzOH,respectively,selectively converting them to p-MBA,P with lower oxidation-reduction potential was suitable for the electro-oxidation of p-MT with lower oxidation potential,while C with higher oxidation-reduction potential was suitable for the electro-oxidation of p-MBzOH with higher oxidation potential.