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

Facile oxygenation of the acyclic amido-chlorosilylene bis(N-heterocyclic carbene) Ni0 complex [{N(Dipp)(SiMe3 )ClSi:→Ni(NHC)2 ] (1; Dipp=2,6-i Pr2 C6 H4 ; N-heterocyclic carbene=C[(i Pr)NC(Me)]2 ) with N2 O 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 π-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 π-complex at low temperature.