Replacement of [Cu(dmp)(xantphos)]PF6 with pDTCz-DPmS as the PC allowed for a higher yield of 73% to be obtained in our setup, a result ostensibly of its suitable redox potentials (Table ). However, there is a significant background reaction where in the absence of PC, a moderate yield of 47% was achieved using our photoreactor, while no formation of product was reported using the literature conditions for this control reaction. We next conducted a series of control reactions with pDTCz-DPmS as documented in Table . The first interrogated the role of the two additives, DIPEA and HE. Both DIPEA and HE are required in addition to pDTCz-DPmS to obtain the optimal yield (entries 2 and 3 versus 1); the presence of DIPEA contributes more significantly to the yield than the HE. The absence of both additives results only in trace product (entry 4) and the removal of light causes no product to be formed (entry 11). These findings are consistent with those of Yang et al. These same control experiments were conducted in the absence of pDTCz-DPmS (entries 5-8).