首次制备了十二烷基硫酸根(DS–)插层水滑石负载的纳米钯无膦配体型的Suzuki偶联反应催化剂.DS–进入到水滑石层间,使层间距从微孔增至2.9nm,从而有利于中等尺度的有机分子在催化剂表面的扩散.进一步以PdCl42–交换该水滑石得到DS–和PdCl42–双插层的水滑石.还原后可得到层间插有金属钯纳米团簇的水滑石.由于DS–插层后在水滑石层板间形成的空间有限,限制了Pd0团簇的进一步生长.作为一种亲油性的非均相催化剂,该类催化剂可有效促进卤代芳烃与苯硼酸的Suzuki偶联反应.催化剂循环使用5次后活性基本得以保持.
The dodecylsulfate anion(DS-) embedded layered double hydroxide(LDH) supported nanopalladium catalyst(LDH-DS-Pd0) is a novel phosphine free recyclable heterogeneous catalytic system for palladium catalyzed Suzuki coupling reactions and has been prepared for the first time.The intercalation of DS-changed the interlayer spacing of LDH from a microsize to a mesosize(2.9 nm) range,which favors the diffusion of average sized organic molecules.The Pd0 clusters obtained from the reduction of PdCl42--interlayered LDH were intercalated between the LDH layers and hence the growth of Pd0 clusters was effectively hindered by the limited space created by the intercalation of DS-.This lipophilic catalyst was highly efficient in promoting the Suzuki reaction of aryl halides with phenylboronic acid.As a heterogeneous nanocatalyst,LDH-DS-Pd0 could be reused five times without significant loss of catalytic activity.