温和条件下PdCl_2催化苯乙烯液相氧化制苯乙酮

Catalytic Behavior of PdCl 2 in Liquid Phase Oxidation of Styrene to Form Acetophenone under Mild Conditions

在温度为５５℃、Ｈ２Ｏ２与苯乙烯的摩尔比为１１５和丙酮作共溶剂的反应条件下，ＰｄＣｌ２对苯乙烯的液相催化反应具有很高的催化活性和苯乙酮的选择性。考察了共溶剂、反应温度以及相转移剂对ＰｄＣｌ２催化性能的影响。结果表明，升高反应温度、以丙酮为共溶剂或以十二烷基硫酸钠作相转移剂均可使反应速度加快。苯乙烯与ＰｄＣｌ２的摩尔比在４００～１５００内可达到高转化率的催化效果。加入配位能力较强的螯合配体，苯乙酮的选择性显著下降，一些酚类自由基抑制剂可使苯甲醛的选择性显著下降。

PdCl 2 exhibits very high catalytic activity and acetophenone selectivity for liquid-phase oxidation of styrene under the reaction conditions of 55℃,H 2O 2/styrene=1.15(mole ratio) and acetone as cosolvent.The effects of cosolvents,temperature and phase transfer reagents on the reaction were investigated.The results show that increasing reaction temperature,using acetone as cosolvent or sodium dodecyl sulfate as phase-transfer reagent can accelerate the reaction.The conversion of styrene is high when the mole ratio of styrene to PdCl 2 is 400～1500.The selectivity for acetophenone decreases significantly on adding some chelating ligands to the catalytic system.The selectivity for benzaldehyde decreases significantly on adding some radical inhibitor to the catalytic system.