Metallaphotoredox catalysis is a capable tool for constructing C(sp2)-N bonds, complementing thermally controlled SNAr, Buchwald Hartwig, Ullmann and Cham-Lam couplings. Typical conditions include the use of nickel salts such as nickel(II) bromide glyme (NiBr2•DME), and DABCO as a multifunctional additive; a stabilising monodentate ligand, an electron donor, hydrogen atom transfer (HAT) agent, and as a base. We began by exploring the amination of methyl 4-bromobenzoate (1a) with mono-Bocprotected piperazine (2a), using NiBr2•DME as the nickel catalyst and [Ir(dF(CF3)ppy)2(dtbbpy)]PF6 ([Ir1]) as the photocatalyst, inspired by the conditions from Buchwald, Macmillan and co-workers. In accordance with our previously reported conditions, all mechanophotocatalysis reactions were conducted under air. As the solution-state reaction typically uses DMA as a solvent, we decided to employ this as a liquid assisted grinding (LAG) agent. Solvent-minimized photocatalysis reactions that we have explored in the past typically manifest as 'sticky-to-slushy' organic pastes. Thus, in order to control the rheology of the mixture to facilitate efficient mixing, we selected sodium sulfate as an inert grinding auxiliary. We found that higher auxiliary loadings were beneficial, with 15 or 18 equivalents of sodium sulfate giving superior NMR yields (71 and 70%) than obtained using only 12 equivalents (52%), Figure . The use of DMSO, another solvent used in the solution-state literature, gave an inferior yield (39%). Decreasing the LAG loading from 6 to 1.5 equivalents did not result in a reduction in the yield (obtaining 67, 70, 69, and 68% for 6, 4.5, 3, and 1.5 equivalents of DMA, respectively); however, removal of the LAG agent decreased the yield significantly (24%), potentially the result of either less efficient mixing of reagents, or because DMA is noninnocent in the reaction mechanism. Indeed, in Ito's metallaredox nickel-catalyzed amination and Browne's manganese-and zinc-driven nickel-catalyzed reactions in ball mills, DMA at comparable loadings was a beneficial additive. Control experiments involving the removal of the photocatalyst, nickel co-catalyst, or light resulted in no reaction, demonstrating that a light-driven dual catalyst system is functioning under a solvent-minimized environment. Interestingly, removal of the milling balls while maintaining the milling speed still afforded a high yield (67%), meaning that the shaking action of the mill alone was sufficient to mix the reagents, which is highly promising for the development of lower energy milling technologies to enable the future scale-up of this technology. Using the auxiliary and LAG loadings optimised for the 0.1 mmol scale reaction, we observed a noticeable increase in yield when changing to a 0.3 mmol scale using larger milling balls (76% with three 5 mm balls), perhaps as a function of an improved milling environment with a larger portion of the reaction vessel full, and larger milling balls used. This highlights the complicated relationship between the yield of a mechanochemical reaction and the myriad reaction parameters that need to be congruently optimized. Further scale-up in the current reaction vessels is limited by the internal volume of the vials. Removal of the milling balls from the 0.3 mmol scale reaction while maintaining milling at 25 Hz resulted in a decreased yield (58%), demonstrating that the increase in scale demands an increased mixing efficiency. Finally, we tested the reaction using our V2 holder with a larger milling ball, which afforded a comparable NMR yield of 76±1% under aerobic conditions.