The paper describes a versatile method for the late installation of radiolabeled trifluoromethyl groups [18F]CF3 or [11C]CF3 at C(sp3) sites in molecules by copper-catalyzed trifluoromethylation of alkyl halides and carboxylic acids.[1] The method employs fluoroform labeled with fluorine-18 or carbon-11, activation of the alkyl center by iodine abstraction with an aryl radical, or photoredox-induced decarboxylation.[Positron emission tomography (PET) requires tracers with radioisotopes such as fluorine-18 or carbon-11, which must be incorporated into the molecule in a small number of steps due to their rapid decay.1 This procedure has enabled the efficient labeling of more than 50 complex molecules and pharmaceuticals.[1] Among the synthesized compounds are the highly desirable radioligands [18F]SL25.1188 and [18F]PS13, which provide longer-lived analogs with fluorine-18 instead of carbon-11 for human PET imaging.The method addresses a long-standing lack of general procedures for radiolabeling trifluoromethyl groups in bioactive molecules.