Reactivity of dianionic hexacoordinate germanium complexes toward organometallic reagents. A new route to organogermanes

Abstract

Lithium and potassium tris(benzene-1,2-diolato) germanates (2a and 2b, respectively) and potassium tris(butane-2,3-diolato)germanate (3) are easily prepared from GeO 2 in quantitative yields. They are very reactive toward orrganometallic reagents, the reactivity depending on the ligands on the germanium. Complexes 2 react with an excess of Grignard reagent to give the corresponding tetraorganogermanes R 4 Ge while the less reactive complex 3 leads to the functional triorganogermanes R 3 GeX. Tetraorganogermanes R 4 Ge while the less reactive complex 3 leads to the functional triorganogermanes R 3 GeX. Tetraorganogermanes can also be prepared from complex 2b by reaction with organic bromides in the presence of Mg (Barbier reaction)