An N-Phosphinoamidinato Borasilenide: A Vinyl Anion Containing a B=Si Double Bond

Abstract

Borasilenes, which feature a heterodinuclear Si=B double bond, are expected to exhibit interesting reactivities. This can be attributed to the two proximal reactive sites—boron and silicon—each with distinct electronic properties. However, borasilenes remain relatively rare due to the challenge of stabilizing them. To achieve a stable borasilene, both the boron and silicon centers must be supported by sterically hindered ligands, which can, however, interfere with their potential applications by introducing steric hindrance. In this work, we report the synthesis of an N-phosphinoamidinato potassium borasilenide (compound 3), which is a vinyl anion containing a B=Si‾ double bond. This B=Si‾ double bond is functional and exhibited new patterns of reactivity towards a range of inorganic and organic substrates, including CuCl(PMe₃), [IrCl(cod)]₂, Me₃SiOTf, and MeOTf, leading to the formation of a transition metal π-complex, boron-silicon-containing metallacycle, neutral borasilene and borylsilane, respectively.