the known examples of dearomative photochemical [4+3] cycloadditions are limited to additions across the central ring of an anthracene. Overall, we have shown that high-throughput experimentation approach could be harnessed to discovery new photocatalytic reactions involving novel pairs of substrate classes. Specifically, our approach enabled the discovery of an unprecedented photocycloadditionoxidation had sufficiently broad scope to enable the synthesis of many complex bridged scaffolds from imidazo[1,2-a]pyrimidines and alternative aromatic substrates. It is anticipated, especially where rational reaction design is challenging, that high-throughput experimentation will be a powerful tool to drive the discovery of new and synthetically-useful reactions.