High‐yield syntheses up to molar scales for salts of [BH(CN)3]− (2) and [BH2(CN)2]− (3) starting from commercially available Na[BH4] (Na5), Na[BH3(CN)] (Na4), BCl3, (CH3)3SiCN, and KCN were developed. Direct conversion of Na5 into K2 was accomplished with (CH3)3SiCN and (CH3)3SiCl as a catalyst in an autoclave. Alternatively, Na5 is converted into Na[BH{OC(O)R}3] (R=alkyl) that is more reactive towards (CH3)3SiCN and thus provides an easy access to salts of 2. Some reaction intermediates were identified, for example, Na[BH(CN){OC(O)Et}2] (Na7 b) and Na[BH(CN)2{OC(O)Et}] (Na8 b). A third entry to 2 and 3 uses ether adducts of BHCl2 or BH2Cl such as the commercial 1,4‐dioxane adducts that react with KCN and (CH3)3SiCN. Alkali metal salts of 2 and 3 are convenient starting materials for organic salts, especially for low viscosity ionic liquids (ILs). [EMIm]3 has the lowest viscosity and highest conductivity with 10.2 mPa s and 32.6 mS cm−1 at 20 °C known for non‐protic ILs. The ILs are thermally, chemically, and electrochemically robust. These properties are crucial for applications in electrochemical devices, for example, dye‐sensitized solar cells (Grätzel cells).

Potassium tricyanofluoroborate, K­[BF­(CN)3], which is the starting material for tricyanofluoroborate room-temperature ionic liquids [N. Ignat’ev et al. J. Fluorine Chem., submitted] was obtained on a molar scale (140 g) from Na­[BF4] and (CH3)3SiCN with a purity of up to 99.9%. The initial product of the reaction that was catalyzed by (CH3)3SiCl was Na­[BF­(CN)3]·(CH3)3SiCN that was characterized by multinuclear NMR and vibrational spectroscopy, elemental analysis, differential scanning calorimetry, and single-crystal X-ray diffraction. Na­[BF­(CN)3]·(CH3)3SiCN was converted to K­[BF­(CN)3] via a simple extraction protocol. The catalytic effect of (CH3)3SiCl was evaluated and some intermediates of the reaction, including the isocyanoborate anion [BF­(NC)­(CN)2]−, were identified using multinuclear NMR and vibrational spectroscopy. K­[BF2(CN)2] also reacted with (CH3)3SiCN in the presence of (CH3)3SiCl, to result in K­[BF­(CN)3]. The interpretation of the experimental observations was supported by data derived from density functional theory (DFT) calculations. In addition, the influence of selected countercations of the tetrafluoroborate anion on the progress of the (CH3)3SiCl-catalyzed reaction was studied. The fastest reaction was observed for Na­[BF4], while the conversion of [BF4]− to [BF­(CN)3]− was slower with the countercation K+. Li­[BF4] and [Et4N]­[BF4] were converted under the reaction conditions applied to Li­[BF2(CN)2] and [Et4N]­[BF2(CN)2] only.

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The reaction of PF with [(Cy P) Pt] gave the PF complex trans-[(Cy P) PtF(PF )][PF ], which was characterized by single-crystal X-ray diffraction, multinuclear NMR spectroscopy, and elemental analysis. To the best of our knowledge, this reaction is the first example of the oxidative addition of a P-F bond to a transition metal and is a rare example of an activation of a main-group-element-fluorine bond by a metal. Relativistic DFT calculations showed that the formation of the Lewis pair [(Cy P) Pt→PF ], which was not observed even at low temperatures, represents the initial step of the reaction. From this key intermediate, the cation trans-[(Cy P) PtF(PF )] was furnished by a two-step mechanism involving, successively, a second and a third PF molecule.

Different types of high‐yield, easily scalable syntheses for cyano(fluoro)borates Kt[BFn(CN)4−n] (n=0–2) (Kt=cation), which are versatile building blocks for materials applications and chemical synthesis, have been developed. Tetrafluoroborates react with trimethylsilyl cyanide in the presence of metal‐free Brønsted or Lewis acid catalysts under unprecedentedly mild conditions to give tricyanofluoroborates or tetracyanoborates. Analogously, pentafluoroethyltrifluoroborates are converted into pentafluoroethyltricyanoborates. Boron trifluoride etherate, alkali metal salts, and trimethylsilyl cyanide selectively yield dicyanodifluoroborates or tricyanofluoroborates. Fluorination of cyanohydridoborates is the third reaction type that includes direct fluorination with, for example, elemental fluorine, stepwise halogenation/fluorination reactions, and electrochemical fluorination (ECF) according to the Simons process. In addition, fluorination of [BH(CN)2{OC(O)Et}]− to result in [BF(CN)2{OC(O)Et}]− is described.