Influence of Electronically and Sterically Tunable Cinnamate Ligands on the Spectroscopic Properties and Reactivity of Bis(triphenylphosphine)platinum(0) Olefin Complexes
作者:Magnus R. Buchner、Bettina Bechlars、Bernhard Wahl、Klaus Ruhland
DOI:10.1021/om301021j
日期:2013.3.25
ester)platinum(0) complexes were synthesized to examine electronic and steric influences on their behavior as inhibited precatalysts and to correlate this with 1H, 13C, 19F, 31P and 195Pt NMR spectroscopic, IR spectroscopic, and X-ray structural properties (9 X-ray structures included). The substituent at the 4-position of the phenyl group proved to be a valuable moiety in controlling the electronic properties
总共合成了48种新的双(三苯基膦)(肉桂酸酯)铂(0)配合物,以研究电子和空间位阻对其作为受抑制前催化剂的行为的影响,并将其与1 H,13 C,19 F,31 P和195 Pt NMR光谱,IR光谱和X射线结构特性(包括9个X射线结构)。事实证明,苯基4位上的取代基是控制烯烃配体电子特性以及控制金属-配体键强度的重要部分。反应性和NMR光谱数据与该取代基的Hammett参数相关:尤其是偶联常数2 J PP和1 J PPt。配合物的反应性是通过三苯膦的NMR滴定法(1 H NMR;触发配体取代)以及与二苯基硅烷的反应(1 H和29 Si NMR;触发氧化加成)确定的。所确定的平衡与烯烃的电子密度相关。作为一个典型的例子,可以从配合物的NMR 2 J PP偶合常数间接预测反应性,这也可以从相关的Pd配合物中发现。