Catalysis is a topic of continuous interest since it was discovered in chemistry centuries ago. Aiming at the advance of reactions for efficient processes, a number of approaches have been developed over the last 180 years, and more recently, porphyrins occupy an important role in this field. Porphyrins and metalloporphyrins are fascinating compounds which are involved in a number of synthetic transformations of great interest for industry and academy. The aim of this review is to cover the most recent progress in reactions catalysed by porphyrins in scalable procedures, thus presenting the state of the art in reactions of epoxidation, sulfoxidation, oxidation of alcohols to carbonyl compounds and C–H functionalization. In addition, the use of porphyrins as photocatalysts in continuous flow processes is covered.

A successful end-to-end continuous flow synthesis of pure curcumin (1) and two other natural derivatives present in turmeric is described. Batch and continuous flow conditions were combined in order to develop the end-to-end process. Three operations were telescoped yielding the three different natural curcuminoids in a safe, gram-scale and reproducible manner.