Fluorosilanes react with lithium amides and organolithium compounds to give aminofluorosilanes and organofluorosilanes. The reactivity of the monoaminofluorosilanes with butyllithium is decreasing with increasing size of the substituents and with their stabilisation in the molecule. Reactions observed include: a) (2 + 2) cycloaddition, b) ring closure under either C–H-cleavage or under migration of a methanideion and c) formation of stable lithio-aminofluorosilanes.