It is hard to imagine the modern world without fluorinated organic compounds. Fluorinated organic compounds are used as pharmaceuticals, agrochemicals and are also employed as solvents and corrosion resistant plastics. Considering all the above we can conclude that the C–F bond is one of the most imporant bonds in organic chemistry. In this diploma thesis, we fluorinated four substrates by palladium catalyzed electrophilic aromatic fluorination in which Selectfluor was used as a source of fluorine, palladium complex as the catalyst and phenantroline as the ligand. We altered the reaction conditions such as temperature (50 °C and 80 °C) and reaction time (24 and 72 hours) and monitored their effect on the conversion of starting materials into products. The conversions into products were determined by 19F NMR using 4-fluorobenzotrifluoride as the internal standard. For the separation of the regioisomers of fluorinated products we used different methods such as column cromatography and destilation.