We have previously shown that photocatalytic decarboxylative alkylations in a solvent-minimized environment are feasible, and thus we anticipated that a decarboxylative arylation under a metallamechanophotoredox framework would also be viable. We began our investigations using the decarboxylative arylation of Boc-protected proline (2c) with 1a using [Ir1] as the photocatalyst, Figure . For ease of use, we opted to use the preformed [Ni(dtbbpy)(OH2)4]Cl2 ([Ni1]) as a bench-stable pre-formed nickel catalyst. Initially, we obtained a poor yield (37%) using low auxiliary and LAG loadings (3 and 1.5 equivalents of sodium sulfate and DMA, respectively). Progressive improvements in yield were made using 6 equivalents of auxiliary (55%) and subsequently 3 equivalents of LAG (64%). A higher LAG loading gave negligible improvements (66% with 4.5 equivalents DMA), as did the use of 9 or 12 equivalents of auxiliary (66 and 68%, respectively), suggesting that a plateau was reached as a function of the optimisation of both parameters. Notably, the nickel catalyst loading could be reduced to 1 mol% while maintaining high yields (68%); a remarkable outcome considering the low loadings of each catalyst used in the absence of bulk solvent.