A Congested in,in-Diphosphine

The synthesis and characterization of the bis(triarylphosphine) 3 are described. Slow protonation of an inwardly directed phosphine is possible, but the phosphines do not react with larger reagents. X-ray structures of the parent compound, its HCl salt, and the corresponding trisulfone are reported. Compound 3 was resolved by chiral chromatography, but the barrier to racemization is only 20.7 kcal/mol.本文报道了双(三芳基膦)(bis(triarylphosphine)) 3的合成与表征。朝向内侧的一个膦原子可发生缓慢质子化，但该类膦无法与大位阻试剂发生反应。本文还报道了该母体化合物、其氯化氢盐以及相应三砜的X射线晶体结构。化合物3可通过手性色谱法进行手性拆分，但其消旋化能垒仅为20.7 kcal/mol。