(BB)-Carboryne Complex of Ruthenium: Synthesis by Double B–H Activation at a Single Metal Center

Abstract

The first example of a transition metal (BB)-carboryne complex containing two boron atoms of the icosahedral cage connected to a single exohedral metal center (POBBOP)Ru(CO)2 (POBBOP = 1,7-OP(i-Pr)2-2,6-dehydro-m-carborane) was synthesized by double B–H activation within the strained m-carboranyl pincer framework. Theoretical calculations revealed that the unique three-membered (BB)>Ru metalacycle is formed by two bent B–Ru σ-bonds with the concomitant increase of the bond order between the two metalated boron atoms. The reactivity of the highly strained electron-rich (BB)-carboryne fragment with small molecules was probed by reactions with electrophiles. The carboryne–carboranyl transformations reported herein represent a new mode of cooperative metal–ligand reactivity of boron-based complexes.

A Highly Active PBP–Iridium Catalyst for the Dehydrogenation of Dimethylamine–Borane: Catalytic Performance and Mechanism

“…According to their structures, we can divide boron‐based pincer ligand systems into two classes. One class is based on the m ‐ or o ‐carborane core, onto which two coordination tethers are attached –. The other class, which is the focus of our research group, is based on the boron‐containing five‐membered ring diazaborole, onto which two coordinating phosphorus moieties are tethered –.…”

Reversible Photothermal Isomerization of Carborane‐Fused Azaborole to Borirane: Synthesis and Reactivity of Carbene‐Stabilized Carborane‐Fused Borirane

“…[13] We are interested in the preparation of carborane-fused borirane 1,2-BR-1,2-C 2 B 10 H 10 because of the very rich reaction chemistry of the corresponding three-membered metallacycles 1,2-[M]-1,2-C 2 B 10 H 10 (M = transition metals). [14,15] However,m any attempts to prepare 1,2-BR-1,2-C 2 B 10 H 10 through the reaction of Li 2 C 2 B 10 H 10 or 1,2-[M]-1,2-C 2 B 10 H 10 with 1equiv of RBX 2 failed. Unprecedentedly, irradiation of acarborane-fused azaborole 1 [16a] gave the first example of carbene-stabilized carborane-fused borirane 2 (Scheme 2).…”

Short‐Lived Orthobenzyne Complexes with Early Transition Metals of Group IV. First Direct Characterization and Electronic Cartography by Coupling FVT/UV‐PES with Calculations

“…The 3D ELF (Figure and Figure S4) and 2D LOL (Figure S5) representations show that the electron density of these M–C bonds is bent outward in the MCC cycle, with two associated basins having a population of 1.94 e – (Ti), 2.25 e – (Zr), and 2.21 e – (Hf). A comparative situation was recently observed in the case of the three‐membered (BB)‐carboryne complex of ruthenium . The drastic decrease in the V(Ti,C) population is correlated with the increase in the population in the V(C1,C2) basin and illustrates the contribution from the π complex structure to the [CpTi(η 2 ‐ c ‐C 6 H 4 )] structure.…”

“…The intermediate complexes [Cp 2 M(η 2 ‐ c ‐C 6 H 4 )] were also subjected to a topological analysis of the electron localization function (ELF), as proposed by B. Silvi and A. Savin , , . ELF basin integrations and 2D localized orbital locator (LOL) maps were computed and plotted by using multifunctional wavefunction analyzer software (Multiwfn, version 3.3.9) .…”