Our aim was to identify an efficient C-H functionalization process for regioselective installation of a versatile functional group in both light and heavy hydrocarbon scaffolds (Figure ). We believed that installing a carbonyl group would bring significant value due to its abundant associated chemistry. We further identified that the most cost-effective strategy for carbonyl installation would utilize readily available, inexpensive carbon monoxide from the hydrocarbon reforming industry (Figure ). However, while safety hazards associated with carbon monoxide in combination with flammable alkanes would pose substantial risks in conventional batch reactors, safe processing can be ensured in flow due to the limited amount of chemicals in the microreactor. Additionally, the short length scales in micro flow reactors result in a uniform irradiation of the reaction mixture, reducing reaction times and providing opportunities for scaling up (Figure ). The use of flow chemistry is crucial to develop a safe, practical and scalable process for the photocatalytic carbonlylation of alkanes.