A microfluidic photoreactor enables 2-methylbenzophenone light-driven reactions with superior performance

Light-driven reactions of 2-methylbenzophenones (2-MBPs) occur with improved yields (up to >98%) and reaction rates (up to 0.240 mmol h(-1)) by using a tailored microfluidic photoreactor (MFP). For the first time, coumarins were converted into 4-benzylated chromanones in high yields (50-93%) and diastereoselectivity (up to >20:1 dr), thus by-passing their photo-dimerisation end-reaction.