金属次卟啉二甲酯催化氧化苯乙烯制苯甲醛

摘要

将金属次卟啉二甲酯用作叔丁基过氧化氢(TBHP)氧化苯乙烯制苯甲醛的催化剂.考察了催化剂、氧化剂用量、反应温度、时间、溶剂和不同金属次卟啉二甲酯[M (DPDME)]对苯乙烯转化率及苯甲醛选择性的影响,初步探索了反应机理.结果表明,金属次卟啉二甲酯能够顺利地选择性催化氧化苯乙烯生成苯甲醛.以0.002 mmol锰次卟啉二甲酯[CIMn(DPDME)]为催化剂,0.4 mmol TBHP为氧化剂,1mmol苯乙烯为底物,5 mL CH3CN/H2O(体积比4∶1)为溶剂,反应温度75℃,常压反应20h,苯乙烯的转化率达到98.3％,苯甲醛的选择性为92.7％.%In the presence of tert-butyl hydroperoxide ( TBHP),metallo-deuteroporphyrin dimethyl esters [M(DPDME)] were used as catalysts in the oxidation of styrene.We have investigated the effects of the amount of the catalyst,the amount of the oxidant,reaction temperature,time,solvents and metallo-deuteroporphyrin dimethyl esters with different central metals on the conversion of styrene and the selectivity of benzaldehyde.The mechanism of the reaction was also discussed.The results indicated that the M(DPDME) could efficiently catalyze selective oxidation of styrene to benzaldehyde in good yields.Under the conditions of 0.002 mmol CIMn ( DPDME) as the catalyst,0.4 mmol TBHP as the oxidatant,1 mmol styrene as the substrate,CH3CN(4 mL)/H2O(l mL) as the solvent,reaction temperature of 75℃,atmospheric pressure,and a reaction time of 20 h,the conversion of styrene reached 98.3% with the benzaldehyde selectivity of 92.7%.