Fluorine-containing functional groups, such as trifluoromethyl groups, play important roles in the production of drugs, agrochemicals, and organic functional materials because the introduction of fluorine atoms into organic compounds can improve the hydrophobicity and metabolic stability of organic molecules. Because organofluorine compounds rarely exist in nature, the development of effective methods to introduce fluorine-containing functional groups into organic compounds is an important research topic in organic chemistry. Regioselective C(sp 2 )-H trifluoromethylation is an efficient method for the synthesis of organofluorine compounds. Although trifluoromethyl radical is generally employed in conventional C(sp 2 )-H trifluoromethylation, it is difficult to control the regioselectivity because of its high reactivity. For instance, the reaction of pyridine with the trifluoromethyl radical gave a mixture of 2-, 3-, and 4-trifluoromethylated products. The regioselective transformations of pyridine rings have been intensively investigated. Pyridines are electron-deficient aromatics that react with nucleophiles at the C2 and C4 7 positions of pyridine rings. Based on their reactivity, we developed 2-and 4-position-selective trifluoromethylation of pyridines and their related compounds using a nucleophilic trifluoromethylation reagent (CF3 anion source) with mild reactivity. The 2-position-selective trifluoromethylation was achieved by the introduction of a strong electron-withdrawing group on the nitrogen atom of the pyridine rings. We succeeded in developing steric repulsion-controlled 4-position-selective trifluoromethylation based on the electrophilic activation of pyridines using a bulky Lewis acid. However, these methods do not apply to trifluoromethylation at the C3 position of pyridine derivatives.