Evidence that SCS Pincer Pd(II) Complexes are only Precatalysts in Heck Catalysis and the Implications for Catalyst Recovery and Reuse
作者:Kunquan Yu、William Sommer、John?M. Richardson、Marcus Weck、Christopher?W. Jones
DOI:10.1002/adsc.200404264
日期:2005.1
SCS-pincer Pd(II) complexes have been covalently immobilized onto porous silica, cross-linked polymer (Merrifield resin) and soluble poly(norbornene) supports via either amide or urea linkages and evaluated in the Heck coupling of iodobenzene with n-butyl acrylate. Kinetic experiments and poisoning studies indicate that in all cases the pincer complexes merely act as precatalysts. Contrary to literature
已通过酰胺或脲键将SCS-pincer Pd(II)络合物共价固定在多孔二氧化硅,交联聚合物(Merrifield树脂)和可溶性聚降冰片烯载体上,并在碘苯与丙烯酸正丁酯的Heck偶联中进行了评估。动力学实验和中毒研究表明,在所有情况下,钳子络合物仅充当预催化剂。与文献报道相反,没有证据表明在这里研究的任何条件下,完整的酰胺连接的SCS-Pd(II)配合物都可以催化。