有机膦配体对钯分子偶联催化剂活性的影响

采用3种不同的有机膦配体，设计和合成出3个有机膦钯(II)配合物，测试和表征了它们的化学结构，分别为trans-{Pd(t-Bu)2PPh]2Cl2}、trans-Pd(Amphos)2Cl2]、cis-Pd(Xantphos)Cl2] ((t-Bu)2PPh=二叔丁基苯基膦、Amphos=二叔丁基-(4-二甲基氨基苯基)膦、Xantphos=4,5-双二苯基膦-9,9-二甲基氧杂蒽)。在2个Suzuki和1个Sonogashira偶联反应模型上，测定了它们的催化活性，考察了膦配体对钯分子偶联催化剂活性的影响，发现膦配体对催化活性有重要影响，且对应不同的反应模型其影响程度不同，影响机制与膦配体的配位能力和分子的空间体积有关。

Influence of organo-phosphine ligands on the catalytic activity of Pd(Ⅱ) complexes in the coupling reactions

Three Pd(II) complexes with various organophosphine ligands, trans-{Pd(t-Bu)2PPh]2Cl2} (t-Bu)2PPh=di-tert-butyl-phenyl phosphine], trans-Pd(Amphos)2Cl2] Amphos=di-tert-butyl-(4-dimethylamino phenyl)phosphine] and cis-Pd(Xantphos)Cl2] Xantphos=4,5-Bis(diphenyl-phosphino)-9,9-dimethylxanthene] were prepared and characterized. Their catalytic activities were tested in two Suzuki and one Sonogashira coupling reaction models. It is found that the organophosphine ligand has an important influence on the catalytic activity of Pd(II) complexes in the coupling reactions, and that its catalytic activity depends on reaction models. The reaction mechanism is suggested to be associated with the coordination potency of the phosphine ligand with Pd(II) and its steric volume.