Remotely controlled flow photo-Fries-type rearrangement of N-vinylazetidinones: an efficient route to structurally diverse 2,3-dihydro-4-pyridones

Abstract

A green and sustainable method for the formation of chiral 2,3-dihydro-4-pyridones via a light-promoted rearrangement of readily available, optically pure N-vinylazetidinones is described. This protocol exhibits good functional group tolerance and broad substrate scope. The reaction proceeds with excellent atom economy under light irradiation alone, without any catalysts or additives. Furthermore, a novel modular set-up, assembled from common, commercially available components, was used for the case studies in flow, enabling convenient remote real-time control of the reaction course via UV-vis spectroscopy.