The coupling of two or more molecules of dinitrogen (N2) occurs naturally under the radiative conditions present in the ionosphere and may be achieved synthetically under ultrahigh pressure or plasma conditions. However, the comparatively low N–N single-bond enthalpy generally renders the catenation of the strongly triple-bonded N2diatomic unfavorable and the decomposition of nitrogen chains a common reaction motif. Here, we report the surprising organoboron-mediated catenation of two N2molecules under near-ambient conditions to form a complex in which a [N4]2–chain bridges two boron centers. The reaction entails reductive coupling of two hypovalent-boron-bound N2units in a single step. Both this complex and a derivative protonated at both ends of the chain were characterized crystallographically.

The [Ni(IMes)2]-catalyzed transformation of fluoroarenes into arylboronic acid pinacol esters via C-F bond activation and transmetalation with bis(pinacolato)diboron (B2pin2) is reported. Various partially fluorinated arenes with different degrees of fluorination were converted into their corresponding boronate esters.

The synthesis of mono‐NHC alane adducts of the type (NHC)⋅AlH3 (NHC=Me2Im (1), Me2ImMe (2), iPr2Im (3 and [D3]‐3), iPr2ImMe (4), Dipp2Im (10); Im=imidazolin‐2‐ylidene, Dipp=2,6‐diisopropylphenyl) and (NHC)⋅AliBu2H (NHC=iPr2Im (11), Dipp2Im (12)) as well as their reactivity towards different types of carbenes is presented. Although the mono‐NHC adducts remained stable at elevated temperatures, ring expansion occurred when (iPr2Im)⋅AlH3 (3) was treated with a second equivalent of the carbene iPr2Im to give (iPr2Im)⋅AlH(RER‐iPr2ImH2) (6). In 6, {(iPr2Im}AlH} is inserted into the NHC ring. In contrast, ring opening was observed with the sterically more demanding Dipp2Im with the formation of (iPr2Im)⋅AlH2(ROR‐Dipp2ImH2)H2Al⋅(iPr2Im) (9). In 9, two {(iPr2Im)⋅AlH2} moieties stabilize the ring‐opened Dipp2Im. If two hydridic sites are blocked, the adducts are stable with respect to further ring expansion or ring opening, as exemplified by the adducts (iPr2Im)⋅AliBu2H (11) and (Dipp2Im)⋅AliBu2H (12). The adducts (NHC)⋅AlH3 and (iPr2Im)⋅AliBu2H reacted with cAACMe by insertion of the carbene carbon atom into the Al−H bond to give (NHC)⋅AlH2/iBu2(cAACMeH) (13–18) instead of ligand substitution, ring‐expansion, or ring‐opened products.

Despite the synthesis of a boryl anion by Yamashita et al. in 2006, compounds that show boron-centered nucleophilicity are still rare and sought-after synthetic goals. A number of such boryl anions have since been prepared, two of which were reported to react with methyl iodide in apparent nucleophilic substitution reactions. One of these, a borolyl anion based on the borole framework, has now been found to display single-electron-transfer (SET) reactivity in its reaction with triorganotetrel halides, which was confirmed by the isolation of the first neutral borole-based radical. The radical was characterized by elemental analysis, single-crystal X-ray crystallography, and EPR spectroscopy, and has implications for the understanding of boron-based nucleophilic behavior and the emergent role of boron radicals in synthesis. This radical reactivity was also exploited in the synthesis of compounds with rare B-Sn and B-Pb bonds, the latter of which was the first isolated and structurally characterized compound with a "noncluster" B-Pb bond.

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).