作者:Ronald J. Cross、James Gemmill
DOI:10.1039/dt9810002317
日期:——
para-substituted aryl groups, R. Values of the equilibrium constants, enthalpy, and entropy of the reactions are presented. The electronic effects of the aryl groups on this R migration reaction are found to be at least as critical as any previously reported factors influencing this process. Electron-donating substituents in meta- or para-positions promote the insertions, whereas electron-withdrawing groups inhibit
已经检查了进行CO插入的[PtCl(R)(CO)(PMePh 2)]的异构体与其卤代插入产物[Pt 2 Cl 2(COR)2(PMePh 2)2 ]之间的平衡,确定了12个邻位- ,元-和对位-取代的芳基基团,平衡常数,焓,反应的熵的R.数值表示。发现芳基基团对该R迁移反应的电子作用至少与先前报道的影响该过程的因素一样重要。供电子取代基中元-或对-位促进插入,而吸电子基团抑制它们。找到与Hammettσ值的相关性。由于空间原因,邻位取代基倾向于阻止该反应。吸电子基团的反应焓变负,这可能反映了增强的Pt-芳基键。