Reactivity of N -(chlorodimethylgermyl)methyl and N -(chlorodimethylsilyl)methyl derivatives of lactams and amides toward Grignard reagents

N -[(Chlorodimethylgermyl)methyl]lactams and -amides containing a five-coordinate germanium atom react with Grignard reagents chemoselectively by the Ge-Cl bond to form four-coordinate germanium compounds. The method of competitive reactions was used to establish that respective five-coordinate germanium and silicon compounds are almost equally reactive toward Grignard reagents but much more reactive than model four-coordinate germanium and silicon compounds.