Di- and Trinuclear Zn<sup>2+</sup> Complexes of Calix[4]arene Based Ligands as Catalysts of Acyl and Phosphoryl Transfer Reactions
作者:Roberta Cacciapaglia、Alessandro Casnati、Luigi Mandolini、David N. Reinhoudt、Riccardo Salvio、Andrea Sartori、Rocco Ungaro
DOI:10.1021/jo0487350
日期:2005.1.1
lower rim hydroxyls, was used as a convenient molecular platform for the design of bi- and trimetallic Zn2+ catalysts. The catalytic activity of the Zn2+ complexes of calix[4]arenes decorated at the 1,2-, 1,3-, and 1,2,3-positions of the upper rim with 2,6-bis[(dimethylamino)methyl]pyridine units were investigated in the cleavage of ester 6 and of the RNA model compound HPNP. High rate enhancements, up
杯[4]芳烃支架,通过低级边缘羟基的适当烷基化而被封闭在视锥构象中,被用作设计双金属和三金属Zn 2+催化剂的便利分子平台。杯[4]芳烃的Zn 2+配合物在2,6-双[(二甲基氨基)的上边缘的1,2-,1,3-和1,2,3-位修饰的催化活性在酯6和RNA模型化合物HPNP的裂解中研究了甲基]吡啶单元。在许多催化剂-底物组合中观察到高达4个数量级的高速率增强。有趣的是,区域异构体双核配合物在酯6裂解中的催化效率顺序。是1,2-邻位≫ 1,3-远端,但在HPNP反应中相反。与双核配合物相比,三核效率更高,这表明了三个Zn 2+离子在催化机理中的协同作用。