Testing extremely poor electron-poor systems, such as nitrobenzene (26), revealed no alkylated products, with the RAE failing to fragment. This was also the case for activated pyridine N-oxide (27). Both of these substrates are precedented to form EDA complexes and the lack of RAE fragmentation is likely due to the donor amine forming an alternative complex with these substrates and outcompeting the RAE. This demonstrates the substrate window, as the electron-poor systems must not form a more favourable EDA complex than the redox auxiliary. Conversely, to prevent alkylation of the phthalimide, substrates must be better radical acceptors than the phthalimide fragment released upon RAE fragmentation. This can be observed in the absence of an alternative aromatic acceptor or when progressively more electron rich (28) substrates are used (Supplementary Section 5.3). To mitigate this competing reaction, an excess of the aromatic coupling substrate (3-5 equiv.) was employed, a strategy common in EDA methodologies using silyl enol ethers, isocyanides, and other radical traps. This requirement for an excess radical-accepting reagent is not prohibitive, as it can be recovered from the reaction mixture, making the method suitable for expensive or late-stage aromatic acceptor substrates (Fig. ).