Metal-porphyrin catalyzed aziridination of alpha-methylstyrene: Batch vs. flow process

This work describes the aziridination process of a-methylstyrene by using electron poor aromatic azides in the presence of metal-based porphyrins as catalysts. Different ruthenium and cobalt-based porphyrins were successfully employed for the synthesis of N-aryl aziridines performed under a traditional batch methodology and under continuous flow conditions. In general, yields obtained using ruthenium-based catalysts in a traditional batch process were higher than those observed when the reaction was performed under flow conditions. However, cobalt-based porphyrins showed better activities and short reaction times when employed in a flow system process. DFT calculations were also performed in order to understand the influence of substituents on the porphyrin ring in the aziridination process.