Beyond Ni{N(SiMe<sub>3</sub>)<sub>2</sub>}<sub>2</sub>: Synthesis of a Stable Solvated Sodium Tris-Amido Nickelate
Andryj M. Borys, Eva Hevia
Abstract
While Ni{N(SiMe3)2}2 is unstable, the thermally stable and chemically robust tris-amido sodium nickelate [Ni{N(SiMe3)2}3][Na(PMDETA)2] can be prepared directly from NiBr2 and 3 equiv of Na{N(SiMe3)2} in the presence of the tridentate ligand PMDETA. Donor effects were found to be the key to sequestering the sodium cation and stabilizing the compound. In the absence of a suitable donor (i.e., under vacuum or in non-donor solvents), the sodium nickelate redistributes to its monometallic components. 1.PMDETA undergoes a 3-fold trans-amination reaction with 2,2′-dipyridylamine (DPA-H) to give Ni(DPA)2(DPA-H) (2). Furthermore, 1.PMDETA is an effective catalyst for the hydrosilylation of the unactivated alkene vinylcyclohexane using diphenylsilane under mild conditions.