1,2- and 1,1-Migratory Insertion Reactions of Silylated Germylene Adducts

The reactions of the PMe3 adduct of the silylated germylene [(Me3Si)3Si]2Ge: with GeCl2·dioxane were found to yield 1,1-migratory insertion products of GeCl2 into one or two Ge–Si bonds. In a related reaction, a germylene was inserted with tris(trimethylsilyl)silyl and vinyl substituents into a Ge–Cl bond of GeCl2. This was followed by intramolecular trimethylsilyl chloride elimination to another cyclic germylene PMe3 adduct. The reaction of the GeCl2 mono-insertion product (Me3Si)3SiGe:GeCl2Si(SiMe3)3 with Me3SiC≡CH gave a mixture of alkyne mono- and diinsertion products. While the reaction of a divinylgermylene with GeCl2·dioxane only results in the exchange of the dioxane of GeCl2 against the divinylgermylene as base, the reaction of [(Me3Si)3Si]2Ge: with one GeCl2·dioxane and three phenylacetylenes gives a trivinylated germane with a chlorogermylene attached to one of the vinyl units.