2,4,6-Triarylphosphinines versus 2,4,6-Triarylpyridines: An Investigation of the Differences in Reactivity between Structurally Related Aromatic Phosphorus and Nitrogen Heterocycles
作者:Jarno J. M. Weemers、Jelena Wiecko、Evgeny A. Pidko、Manuela Weber、Martin Lutz、Christian Müller
DOI:10.1002/chem.201302441
日期:2013.10.18
Compound rac‐10 could be further dehydrogenated by treatment with DDQ to the benzo(h)quinoline derivative rac‐12. This conversion failed for the phosphorus analogue rac‐3. Interestingly, although 2,4,6‐triarylphosphinines undergo facile CH activation with [Cp*IrCl2]2 in the presence of NaOAc, this reaction does not proceed with the corresponding pyridine derivatives. On the other hand, the latter
新型阻转异构吡啶衍生物rac - 10已合成并进行了结构表征。与它的磷类似物3相反,轴向手性10具有相当低的旋转势垒,如通过DFT计算所估计的。然而,两种对映异构体的存在可以通过手性分析HPLC分析和通过手性酸的质子化实验来证实。化合物rac - 10可以通过用DDQ处理进一步脱氢成苯并(h)喹啉衍生物rac - 12。磷类似物rac - 3的转化失败。有趣的是,虽然2,4,6- triarylphosphinines经历容易Ç ħ活化用的[Cp *的IrCl 2 ] 2中的NaOAc的存在下,该反应不与相应的吡啶衍生物进行。另一方面,后一种可以用Pd(OAc)2选择性地进行原金属化,生成乙酸盐桥联的二聚体物种,可以通过X射线晶体结构分析明确地证实这一点。用Pd(OAc)2对膦进行的处理反而导致了异常的界面氧化偶联产物16和17的形成,它们由含磷的笼状结构组成。