We present a photo- and Cu-mediated 11C cyanation of bench-stable (hetero)aryl thianthrenium salts via an aryl radical addition pathway. The thianthrenium substrates can be readily accessed via C-H functionalization, and the radiocyanation protocol proceeds under mild conditions (<50 °C, 5 min) and can be automated using open-source, readily accessible augmentations to existing radiochemistry equipment.