To obtain a more direct route to the [P(Si i Pr3)2] -anion than previously reported, we looked to the synthesis of P(Si i Pr3)3 published by von Hänisch. Here, red phosphorus was reacted with NaK in refluxing DME to generate (Na/K)3P, which was subsequently reacted with i Pr3SiCl. Since P(SiMe3)3 can be converted to (Me3Si)2PH by hydrolysis or methanolysis, we postulated that it could be possible to obtain ( i Pr3Si)2PH in a similar manner. However, the use of highly pyrophoric NaK alloy was a safety concern. To mitigate this, we instead used Na with 10 mol% naphthalene as an electron transfer agent. This method has been used previously to generate Na3P in situ, for the preparation of tris(trimethylsilyl)phosphine, P(SiMe3)3. In our initial testing, we found that it was necessary to reflux the Na/naphthalene and red P for 24 hours in DME, otherwise the resultant product contained significant amounts of unreacted i Pr3SiCl and ( i Pr3Si)2. This is believed to occur due to incomplete formation of Na3P and the presence of unreacted Na. When monitoring the reaction by P{ 1 H} NMR spectroscopy, we found that a mixture of P containing species were formed, including ( i Pr3Si)3P and ( i Pr3Si)2PH, which were identified by comparison with the literature. Another significant 31 P NMR signal was observed at -378 ppm (compound 1). By removing the DME in vacuo, then extracting the resulting residue in hexane or toluene, it was possible to precipitate 1 from the reaction mixture as a white pyrophoric solid, while P(Si i Pr3)3, ( i Pr3Si)2PH, and other P-containing by-products remained in solution. 1 H, 13 C{ 1 H}, 31 P, and 31 P{ 1 H} NMR spectroscopy of 1 suggested the complex contained an -P(Si i Pr3)2 moiety with no minor residual solvent peaks (see Supporting Information Figures and). While it was not possible to obtain crystals of 1 suitable for single crystal X-ray diffraction studies, crystals of [(THF)NaP(Si i Pr3)2]2 (1a) were obtained when a reaction mixture containing 1 was dissolved in C6D6 and THF (Figure ) and left at room temperature for four weeks. Based on this structure and the NMR spectroscopic data, we propose that 1 corresponds to NaP(Si i Pr3)2. Due to the very high sensitivity of 1, it was not possible to obtain high resolution mass spectrometric data on this compound. Given that our aim had been to convert P(Si i Pr3)3 to the [P(Si i Pr3)2] -anion via a multi-step process, the observation of 1 was quite exciting. Here, we were directly forming a phosphanide anion in a single step and purifying it by precipitation and filtration. Thus, we focused on optimising the synthesis to maximise the yield of 1, rather than P(Si i Pr3)3. This led to the development of the methodology shown in Scheme 1. Na and 10 mol% naphthalene were refluxed in DME for 24 hours, after which i Pr3SiCl was added and the reaction heated for a further 24 hours. After filtration to remove insoluble impurities, the DME was removed in vacuo and the resulting oil was extracted into toluene. This precipitated 1, which was isolated by filtration in 42% yield and sufficient purity for further synthesis. The crude reaction mixture showed the formation of 1, ( i Pr3Si)2PH and P(Si i Pr3)3 in an approximate 1:0.28:0.08 ratio (see Supporting Information Figure ). As ( i Pr3Si)2PH has been previously shown to be readily converted to [(THF)LiP(Si i Pr3)2]2, which can also be used in transmetallation reactions, it is suggested that isolation of this by-product would further increase the yield of usable phosphanide precursors from this reaction. Note that, concurrent with our reported work, the Mills group has developed a similar (albeit lower yielding) synthesis of 1. Scheme 1. Optimised synthesis of NaP(Si i Pr3)2 (1).