Venturing further, we subjected a diverse set of H-donor substrates to our flow-based electrophotocatalytic reaction conditions. Efficient α-to-O C(sp 3 )-H functionalization across various cyclic and linear ethers delivered the sought-after compounds in commendable yields . Notably, selective α-to-S and α-to-N C-H bond functionalization was observed as well , maintaining excellent selectivity over competing α-to-O C-H activation, as seen, for instance, with compound 18. Our method also demonstrated capability in functionalizing benzylic positions; xanthene was functionalized yielding notably high yields (21, 95%). Remarkably, functionalization of the nonsteroidal anti-inflammatory drug pranoprofen was accomplished, procuring product 22 (67% yield). Finally, our benchmark reaction involving ethyl pyrazole-4-carboxylate (1a) and tetrahydrofuran (2a) was readily scaled up in flow using the standard procedure, with an enhanced concentration (0.3 M) and a larger H-donor excess (10 equiv) for extended operation times (5 mmol, 70% isolated yield, productivity: 1 mmolꞏh -1 ). The reactor maintained adequate performance even after 210 minutes (corresponding to 14 residence times).