Photochemistry at Scale: Wireless Light Emitters Drive Sustainability in Process Research & Development

Abstract

Carbon−carbon bond formation by dual Iridium-Nickel photoredox catalysis has gained a lot of attention for late-stage cross-couplings of alkyls with aryls. However, the scalability of such reactions is greatly impeded by the poor light penetration depth into the strongly absorbing reaction media. Wireless internal illumination is a novel technique which circumvents the light penetration issue efficiently and therefore allows to scale photon-driven reactions by conventional methods. Here we demonstrate that industrially relevant photoredox C−C couplings can be scaled seamlessly to different volumes, achieving qualitatively and quantitatively the same results at all scales. The use of conventional reactor types allows stirred, bubble column or fixed-bed operation mode and is fully compatible with heterogeneous reaction mixtures. By minimizing reflection losses, we could also show a significant advantage in the reaction rate over an externally illuminated setup at the same light intensity.