Orthopalladated phosphinite complexes as high-activity catalysts for the Suzuki reaction
作者:Robin B. Bedford、Samantha L. Hazelwood (née Welch)、Peter N. Horton、Michael B. Hursthouse
DOI:10.1039/b303657j
日期:——
phosphinite ligands PR2(OAr) (R = Ph, iPr), their simple complexes with palladium(II) and their palladacyclic complexes has been investigated. The crystal structure of one of the palladacyclic complexes, [Pd(μ2-Cl)κ2-P,C-PiPr2(OC6H2-2,4-tBu2)}2], has been determined. The palladacyclic complexes show extremely high activity in the Suzuki coupling of aryl bromide substrates with phenylboronic acid and can
一系列次膦酸酯的合成 配体PR 2(OAr)(R = Ph,i Pr),它们与钯(II)的简单配合物及其钯环配合物已得到研究。所述palladacyclic络合物中的一个的晶体结构,[的Pd(μ 2 -Cl)κ 2 - P,Ç -P我镨2(OC 6 H ^ 2 -2,4-吨卜2)} 2 ],有被确定。Palladacyclic配合物在芳基溴化物底物与Suzuki偶联的Suzuki偶联中显示出极高的活性苯硼酸还可与烷基硼酸底物一起使用。次膦酸酯基的比较催化剂与基于亚磷酸酯和膦的体系相当的产品突显了其卓越的活性。次膦酸酯的原金属化配体在预催化剂中似乎对于最佳活性至关重要。尽管次膦酸酯四环化合物仅在活化和未活化的芳基氯化物底物的偶联中具有中等活性,但它们的三环己基膦 加合物在失活的底物偶联中被证明具有很高的活性, 4-氯茴香醚。与其他四环系统相比,这种高活性的解释是:催化剂长寿。原金属化的预