UV completions of effective models explaining B-physics anomalies

In recent years several anomalies have been observed in decays of B-mesons. We give first a brief overview on the experimental situation. It is well know that these anomalies can be explained by adding leptoquarks or extra vector-bosons to the SM particle content. We will discuss various possible UV-completions of the resulting effective models and focus in 
particular on the challenges one faces due to bounds from other flavour observables.