The present invention relates to an amidine containing at least one structure unit of formula (I) and to the use thereof as a catalyst for the cross-linking of a functional compound, in particular a polymer comprising silane groups. In a simple method, the described amidine can be produced from readily available feedstocks, largely odourless at room temperature, and with low toxicity. It accelerates the cross-linking of functional compounds surprisingly well and via the radical to which the structure unit of formula (I) is bound, can be adjusted for optimum compatibility with different compositions, as a result of which such compositions have a low propensity for migration-related defects such as separation, exudation or dirt retention by the substrate.