Additionsreaktionen an intramolekular basenstabilisierte GeN‐ und GeS‐Doppelbindungen

Addition Reactions of Intramolecularly Base‐Stabilized GeN and GeS Double Bonds. The GeN bond of 1 adds hydrogen chloride, ethanol, tert ‐butyl alcohol, methyllithium, and methyl iodide to form 3 – 6 and 8 . The GeS bond in 2 analogously adds methyl iodide to yield 10 . In the resulting products the electropositive part of the polar reactand is bound to nitrogen or sulfur, while the electronegative one is on the germanium atom. In the lithium derivative 6 and in the iodine derivative 8 Li and I can be replaced by hydrogen to form two isomers of the same composition 7 and 9 , which differ only in the positions of the hydrogen and methyl groups with respect to Ge or N. The X‐ray structure analyses on 4, 9 , and 10 reveal that the germanium atom is fourfold coordinated by two nitrogen atoms and two other ligands. The intramolecular nitrogen base of the silazyl moiety in 1 and 2 is, thus, expelled from the coordination sphere of germanium by insertion of the double bonds into polar σ bonds, and the tricyclic molecule is changed to a bicyclic one. Thus these “base stabilized π bonds” in 1 and 2 behave as normal unsaturated systems.