Synthesis, Structure, and Reactivity of a Terminal Magnesium Hydride Compound with a Carbatrane Motif, [TismPriBenz]MgH: A Multifunctional Catalyst for Hydrosilylation and Hydroboration

The tris [(1-isopropylbenzimidazol-2-yl)dimethylsilyl)]methyl ligand, [Tism Pr i Benz ], has been employed to form the magnesium carbatrane compound, [Tism Pr i Benz ]MgH, which possesses a terminal hydride ligand. Specifically, [Tism Pr i Benz ]MgH is obtained via the reaction of [Tism Pr i Benz ]MgMe with PhSiH 3 . The reactivity of [Tism Pr i Benz ]MgMe and [Tism Pr i Benz ]MgH allows access to a variety of other structurally characterized carbatrane derivatives, including [Tism Pr i Benz ]MgX [X = F, Cl, Br, I, SH, N(H)Ph, CH(Me)Ph, O 2 CMe, S 2 CMe]. In addition, [Tism Pr i Benz ]MgH is a catalyst for (i) hydrosilylation and hydroboration of styrene to afford the Markovnikov products, Ph(Me)C(H)SiH 2 Ph and Ph(Me)C(H)Bpin, and (ii) hydroboration of carbodiimides and pyridine to form N -boryl formamidines and N -boryl 1,4- and 1,2-dihydropyridines, respectively.