Herein, we present a simple synthesis of mixed-valent phosphinophosphoranes bearing three- and five-coordinate phosphorus centers. Compounds with phosphorus–phosphorus bonds were synthesized via a reaction of lithium phosphides RR′PLi with cat₂PCl (cat = catecholate), whereas derivatives with methylene-linked phosphorus centers were obtained via a reaction of phosphanylmethanides RR′CH₂Li with cat₂PCl. The presence of accessible lone-pair electrons on the P-phosphanyl atom of phosphinophosphoranes during the reaction of the title compounds with H₃B·SMe₂, where phosphinophosphorane-borane adducts were formed quantitatively, was confirmed. Furthermore, the Lewis basic and Lewis acidic properties of the phosphinophosphoranes in reactions with phenyl isothiocyanate were tested. Depending on the structure of the starting phosphinophosphorane, phosphinophosphorylation of PhNCS or formation of a five-membered zwitterionic adduct was observed. The structures of the isolated compounds were unambiguously determined by heteronuclear nuclear magnetic resonance spectroscopy and single-crystal X-ray diffraction. Moreover, by applying density functional theory calculations, we compared the Lewis basicity and nucleophilicity of diversified trivalent P-centers.

中文翻译：

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膦基正膦：具有两亲性的混合价磷化合物

在这里，我们提出了一种带有三和五配位磷中心的混合价膦基正膦的简单合成。具有磷-磷键的化合物是通过磷化锂 RR'PLi 与 cat ₂ PCl（cat = 儿茶酚酸酯）的反应合成的，而具有亚甲基连接的磷中心的衍生物是通过磷烷基甲烷 RR'CH ₂ Li 与 cat ₂的反应获得的PCl。_{在标题化合物与 H 3} B·SMe ₂的反应过程中，膦基正膦的 P-磷烷基原子上存在可接近的孤对电子，其中定量形成膦基膦 - 硼烷加合物，得到证实。此外，还测试了膦基正膦与异硫氰酸苯酯反应时的路易斯碱性和路易斯酸性。根据起始膦基正膦的结构，观察到 PhNCS 的膦基磷酸化或五元两性离子加合物的形成。通过异核核磁共振光谱和单晶 X 射线衍射明确确定了分离化合物的结构。此外，通过应用密度泛函理论计算，我们比较了多样化三价 P 中心的路易斯碱度和亲核性。