Continuous flow reactor technology has a proven track record in enabling photochemical transformations. However, transfer of a photochemical batch process to a flow protocol often remains elusive, especially when solid reagents or catalysts are employed. 

In this work, application of an oscillatory plug flow photoreactor enabled a heterogeneous MacMillan-type C(sp2)–C(sp3) cross-electrophile coupling. Combination of an oscillatory flow regime with static mixing elements imparts exquisite control over the mixing intensity and residence time distribution, pinpointing a mindset shift concerning slurry handling in continuous flow reactors. The C(sp2)–C(sp3) cross-electrophile coupling was successfully transferred from batch to flow, resulting in an intensified slurry process with significantly reduced reaction time and increased productivity (0.87 g/h).

Debrouwer, W.; Kimpe, W.; Dangreau, R.; Huvaere, K.; Gemoets, H. P. L.; Mottaghi, M.; Kuhn, S.; van Aken, K. Org. Process Res. Dev. 2020, 1010, 2319–2325.