Use of Photon Equivalents as a Parameter for Scaling Photoredox Reactions in Flow: the translation of a photocatalytic C‐N cross‐coupling from lab scale to multikilogram scale

With the development of new photocatalytic methods over recent decades, the translation of these chemical reactions to industrial production scales using continuous flow reactors has become a topic of increasing interest. In this context, we describe our studies toward elucidating an empirically-derived parameter for scaling photocatalytic reactions in flow. By evaluating the performance of a photocatalytic C-N cross-coupling across multiple reactor sizes and geometries, it was demonstrated that expressing product yield as a function of the absorbed photon equivalents provided a predictive, empirical scaling parameter. Through the use of this scaling factor and characterization of the photonic flux within each reactor, the cross-coupling was scaled successfully from milligram-scale in batch to a multi-kilogram reaction in flow.