Tris(pentafluoroethyl)germane: Deprotonation and Hydrogermylation Reactions.

Abstract

Owing to the highly electron-withdrawing C2 F5 groups, the tris(pentafluoroethyl)germane (C2 F5 )3 GeH represents an interesting Brønsted acidic compound. The germane is accessible by the treatment of the corresponding halogenogermanes (C2 F5 )3 GeX (X=Cl, Br) with Bu3 SnH. After clarifying its molecular structure in the solid state by X-ray diffraction, the acidity of (C2 F5 )3 GeH was examined by treatment with different bases, for example, 1,8-bis(dimethylamino)naphthalene. The resulting germanate(II) ion [Ge(C2 F5 )3 ]- serves as a germyl group transfer reagent. The reaction with main-group and transition-metal complexes or organohalides opens access to a variety of different compounds, the structures of which were mostly determined by X-ray diffraction. The corresponding tricarbonylnickelate(0) complex [(CO)3 NiGe(C2 F5 )3 ]- also gives information about the π-acceptor properties of the [Ge(C2 F5 )3 ]- ligand. Furthermore, hydrogermylation reactions of (C2 F5 )3 GeH with alkynes afforded different stereoisomers (α,β-cis, β-trans) depending on the respective reaction conditions and substrates.