Synthesis of vinyl germylenes.

A disilylated germylene phosphine adduct was obtained by reaction of tris(trimethylsilyl)silyl potassium with PMe3 and GeCl2·dioxane. The adduct reacted with tolane to give a germacyclopropene, while reactions with phenylacetylene occurred by insertion into the Si-Ge bonds giving vinylgermylene adducts. Release of the mono- or divinylgermylenes by base abstraction led to insertion into Si-Si bonds and formation of silagermetes.