Visible-Light-Induced Chemodivergent Synthesis of Tetracyclic Quinazolinones and 3-Iminoisoindoliones via the Substrate Control Strategy.

A visible-light-induced chemodivergent synthesis of tetracyclic quinazolinones and 3-iminoisoindoliones has been developed. This chemodivergent reaction afforded two kinds of different products by substrate control. A detailed investigation of the reaction mechanism revealed that this consecutive photoinduced electron transfer (ConPET) cascade cyclization involved a radical process, and the aryl radical was the crucial intermediate. This method employed 4-DPAIPN as a photocatalyst and i -Pr 2 NEt as a sacrificial electron donor leading to metal-free conditions.