摘要
制备了强碱性阴离子交换树脂（）负载钯（０）催化剂，发现它对有机锡试剂和有机卤化物的偶联反应有很高的催化活性，分离容易，可重复使用．起催化作用的是金属态把．ＸＰＳ等实验结果表明，在催化剂中钯作为桥将功能基－Ｎ（ＣＨ３）３与ＯＨ－联结起来．催化剂中的把可以看作是两配位的和配位不饱和的，经过氧化加成、金属交换、还原消除过程完成催化反应．
Pd(0) catalyst supported on strong basic anion-exchange resin was prepared.The catalyst has high catalytic activity in the coupling reaction of organotins and organic handes.It can be separated easily from the reaction mixture after reaction and can be reused for several times.The structure of the catalysts was studied by XPS. The experimental data showed that PdCl2 supported on ion-exchange resin was combined with the functional group -N(CH3)3. After D717-PdCl2-was treated with H2NNH2H2O,Pd(Ⅱ)was reduced to Pd(0)and was bound on N (CH3)3,Pd(0)as a bridge makes the OH-interact with -N(CH3)3The metallic Pd may be the catalytic active center for the coupling reaction. A possible catalytic cycle is consistent with homogeneous complexing catalysis of Pd involving sequential oxidative addition,transmetallation and reductive elimination.
关键词
催化
有机锡试剂
有机卤化物
偶联
Pd (0)/anion-exchange resin
organotin reagent
organic halide
coupling reaction
