Oxidative Addition at a Carbene Center: Synthesis of an Iminoboryl–CAAC Adduct

Abstract

The reaction of a cyclic (alkyl)(amino)carbene (CAAC) with dichloro- and dibromobis(trimethylsilyl)aminoborane results in the formation of haloiminoborane-CAAC adducts. When the iodo analogue is used, an oxidative addition at the carbene center affords a cationic iminoboryl-CAAC adduct, featuring a boron-nitrogen triple bond. Similar salts are also obtained by halide abstraction from the chloro- and bromoiminoborane-CAAC adducts. The reactivity of all of these compounds towards CO2 is discussed.

Synthesis and Structure of N,N‐Dinitroamidoborane Complexes

“…Quantum chemical calculations at the DFT‐D3 rm062x/cc‐pvtz (CH 2 Cl 2 solution, smd) level suggest that for both pathways the activation energies appear to be too high for the 1,3‐isomerization processes to proceed at room temperature (although they are possible at elevated temperatures). Interestingly, 1,3‐[ N , O ]‐ and 1,3‐[ O , O ]‐migrations in both mechanisms involve metastable intermediates I1 (1,3‐[ N , O ]‐migration; Scheme ) and I4 (1,3‐[ O , O ]‐migrations; Scheme ), which possess a four‐coordinated boron atom . These results are in agreement with high activation energies of 1,3‐[ N , O ]‐ and 1,3‐[ O , O ]‐migrations of protons in dinitroamine, as demonstrated by quantum chemical calculations performed by Rahm and Brink…”

Unraveling the reactivity of a cationic iminoborane: avenues to unusual boron cations

“…of [PPN]Cl (PPN ¼ Ph 3 P]N]PPh 3 ) or [Ph 4 P]Br in toluene at ambient temperature gave the respective B-halogen substituted iminoboranes 4 and 2 smoothly (Scheme 2). The boron atom in 4 was observed at 12.8 ppm in the 11 B NMR spectrum and the single-crystal X-ray analysis elucidated that 4 adopts a formal Z conguration similar to compound 2 (Fig. 4a).…”

Gallium Ligand Coordinated Group 15 Compounds (LGa−ECp', L=(CHNMe)2CH, E=N − Bi, Cp'=η1‐C5H5): Changeover from Electron‐Sharing to Donor‐Acceptor σ‐Interaction

“…The iminoborane shows a linear geometry with a triple bond character, and the linearity changed to a trans-bent geometry as the group 15 element changes to heavier elements. [24][25][26][27][28][29] There are several reports of multiply bonded group 13 -group 15 compounds viz., β-diketiminate aluminium and gallium imides, [30,31] gallium and indium imides with bulky aryl groups, [32,33] donor stabilized phosphinoboranes, arsinoboranes and the iminoalane. [34][35][36][37] In all these reported compounds, the lightest one is either from group 13 or group 15.…”