Dankert Fabian, Fischer Malte, Hering-Junghans Christian
Leibniz Institut für Katalyse e.V., Katalyse mit phosphorhaltigen Materialien, Albert-Einstein-Straße 29a, 18059 Rostock, Germany.
Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK.
Dalton Trans. 2022 Aug 2;51(30):11267-11276. doi: 10.1039/d2dt01575g.
Phosphanylidenephosphoranes of the type R-P(PR'), also known as phospha-Wittig reagents, can be utilized in a variety of bond activation reactions exploiting their phosphinidenoid reactivity. Herein, we thoroughly show that a facile PMe for HO exchange gives access to various primary phosphine oxides of the general formula RP(H)O (R = Mes*, Ter, Ter) and the molecular structure of TerP(O)H was determined. However, phosphanylidenephosphoranes are described to be highly nucleophilic as well. We show that the attachment of main group Lewis acids such as GaCl and GaI to R-P(PMe) yielded the highly sensitive, yet stable coordination compounds [(RPGaX)PMe] (R = Mes*, Ter) or [(RPPMe)GaCl]GaCl (R = Ter). In contrast to the free phosphanylidenephosphoranes, these species reacted differently with HO, which was demonstrated for [(MesPPMe)GaI]. Here the formation of the phosphino-phosphonium cation [MesP(H)PMe] and different anions was observed with combined NMR spectroscopic and SC-XRD (SC-XRD = single crystal X-ray diffraction analysis) studies. This work demonstrates that the ambiphilic character of phosphanylidenephosphoranes can be utilized to manipulate the reactivity of R-P(PMe) towards water, giving primary phosphine oxides, whereas the Lewis acid adducts [(RPGaX)PMe] gave phosphino-phosphonium species.
R-P(PR')型磷亚基磷烷，也被称为磷叶立德试剂，可利用其磷烯类反应性应用于各种键活化反应。在此，我们充分证明了一个简单的PMe与HO交换反应可以得到通式为RP(H)O（R = Mes*、Ter、Ter）的各种伯膦氧化物，并确定了TerP(O)H的分子结构。然而，磷亚基磷烷也被描述为具有高度亲核性。我们表明，将主族路易斯酸如GaCl和GaI连接到R-P(PMe)上，会生成高度敏感但稳定的配位化合物[(RPGaX)PMe]（R = Mes*、Ter）或[(RPPMe)GaCl]GaCl（R = Ter）。与游离的磷亚基磷烷不同，这些物种与HO的反应不同，这在[(MesPPMe)GaI]中得到了证明。通过核磁共振光谱和单晶X射线衍射分析（SC-XRD）相结合的研究，观察到了膦基鏻阳离子[MesP(H)PMe]和不同阴离子的形成。这项工作表明，磷亚基磷烷的双亲性可以用来控制R-P(PMe)对水的反应性，生成伯膦氧化物，而路易斯酸加合物[(RPGaX)PMe]则生成膦基鏻物种。
