A visible light-driven Minisci-type reaction with N-hydroxyphthalimide esters

Abstract

A visible light-promoted protocol for the redox-neutral coupling of N-hydroxyphthalimide esters with different n-heterocyclic compounds is described. the reaction proceeds through an alkyl radical intermediate generated by reductive decarboxylation of n-hydroxyphthalimide esters. in contrast to the original minisci protocol, polyalkylation can largely be avoided. mechanistic investigations revealed a radical chain mechanism which in some cases can proceed even if no photocatalyst is added. this valuable and functional group-tolerant reaction produces substituted heterocycles in moderate to excellent yield. the use of inexpensive starting materials and leds as the light source are key features of this c–c bond formation.