However, it also exhibits significant limitations such as providing solely C2 selectivity and requiring strong acidic conditions limiting its functional group tolerance (Fig. ). The generation of radical species through the photoactivation of electron donor-acceptor (EDA) complexes has been precedented since the 1950s, but it has only recently emerged as a useful tool in organic chemistry and remains underexploited in organic catalysis. EDA catalysis offers the advantage of producing radicals under mild conditions, with highly targeted photoreactivity achievable through substrate design. Initial applications of EDA catalysis were limited to highly specific donor-acceptor pairs, typically requiring a preinstalled leaving group. The introduction of redox auxiliaries (RAs) or 'redox tags' as components of EDA complexes has broadened its synthetic utility and in the presence of a donor species (D) can facilitate a charge transfer absorption band in the visible spectrum.