Synthesis of a Metallo-Iminosilane via a Silanone-Metal π-Complex

Facile oxygenation of the acyclic amido-chlorosilylene bis(N-heterocyclic carbene) Ni-0 complex [{N(Dipp)(SiMe3) ClSi -> Ni(NHC)(2)] (1; Dipp= 2,6-(Pr2C6H4)-Pr-i; N-hetero-cyclic carbene= C[(Pr-i) NC(Me)](2)) with N2O furnishes the first Si-metalated iminosilane, [DippN=Si(OSiMe3) Ni(Cl)(NHC)(2)] (3), in a rearrangement cascade. Markedly, the formation of 3 proceeds via the silanone (Si=O)-Ni p-complex 2 as the initial product, which was predicted by DFT calculations and observed spectroscopically. The Si=O and Si=N moieties in 2 and 3, respectively, show remarkable hydroboration reactivity towards H-B bonds of boranes, in the former case corroborating the proposed formation of a (Si=O)-Ni p-complex at low temperature.