Cascade Functionalization of C(sp³)–Br/C(sp²)–H Bonds: Access to Fused Benzo[<i>e</i>]isoindole-1,3,5-trione via Visible-Light-Induced Reductive Radical Relay Strategy

Abstract

A reductive radical relay strategy for the construction of fused benzo[<i>e</i>]isoindole-1,3,5-trione through a reaction of α-bromo ketones with maleimides in the presence of Ir(ppy)₃ under visible-light irradiation is described. The protocol employs very mild reaction conditions and offers satisfactory yields. Moreover, the reaction proceeds through a cascade C(sp³)-Br/C(sp²)-H functionalization, double C-C bond formation, and oxidative aromatization sequence.