Initially, toxic NiCl2•6H2O was replaced by safer NiBr2•diglyme, while N-methyl-2-pyrrolidone (NMP) was preferred to DMF as the solvent. Under these conditions, UAA 2 was observed by quantitative UPLC in 42% yield (entry 1), a value in agreement with the yield reported for homotyrosine by Baran and co-workers (54%). As reported also in their work, dimerization of the unstable primary radical accounted for the rest of the mass balance. Isolation of 2 required two purifications by flash chromatography, thus causing a reduced isolated yield (28%). Replacing the aryl bromide with 4-iodobenzaldehyde furnished 2 in a lower yield (entry 2), a result in apparent disagreement with the work of Baran and co-workers. We believe that the sluggish oxidative addition of these substrates and the different solubility of AgBr vs AgCl could favor the aryl bromide over the aryl iodide depending on the substrate under investigation. Performing the reaction in the absence of the nickel catalyst or without AgNO3 resulted in no productive coupling (entry 3 and 4, respectively), whereas replacing AgNO3 with Fe(OAc)2 gave 2 in 20% UPLC yield (entry 5). This is particularly important since highlights that silver can act both forming in situ Ag-functionalized electrodes (as previously determined), and as a mediator, thus making it replaceable by iron which does not form nanoparticles at the electrode. Attempts to replace the sacrificial magnesium anode with a glassy carbon (GC) electrode gave no reaction (entry 6), supporting the role of magnesium as a source of electrons. Notably, the magnesium sacrificial anode could be replaced with aluminium which increases the sustainability of the process (entry 7). Attempts to replace the counter electrode with platinum-or graphite-based ones were unsuccessful (entry 8), therefore pointing out how a large surface area is key in these decarboxylative arylations. Nevertheless, the use of nickel foam as the counter electrode showed reactivity to some extent (entry 9). This, in combination with aluminium as the sacrificial anode gave product 2 in 39% (entry 10), thus providing a cheaper and safer alternative to previously reported working conditions. Based on the optimization study and in analogy with previous results, a nickel-based catalytic mechanism system is believed to be responsible for the C(sp 2 )-C(sp 3 ) coupling, with the deposition of silver nanoparticles on the electrode having a key role in the reactivity. However, in addition to this established mechanism, a concomitant pathway involving silver or other additives as a mediator could occur too, as observed when performing the reaction with FeOAc and using brand-new electrodes.