Organogermanium(II) Hydrides as a Source of Highly Soluble LiH.

The reactions of monomeric C,N-chelated organogermanium(II) hydride L(H)Ge⋅BH with organolithium salts RLi yielded lithium hydrogermanatoborates (Li(THF) {BH [L(H)GeR]}) . Compound (Li(THF) {BH [L(H)GePh]}) was used as a source of LiH for the reduction of organic C=O or C=N bonds in nonpolar solvents accompanied by the elimination of a neutral complex L(Ph)Ge⋅BH . The interaction of (Li(THF) {BH [L(H)GePh]}) with the polar C=O bond was further investigated by computational studies revealing a plausible geometry of a pre-reactive intermediate. The experimental and theoretical studies suggest that, although the Li atom of (Li(THF) {BH [L(H)GePh]}) coordinates the C=O bond, the GeH fragment is the active species in the reduction reaction. Finally, benzaldehyde was reduced by a mixture of L(H)Ge⋅BH with PhLi in nonpolar solvents.