Photoredox Catalyzed Radical Cascade Aroylation (Sulfonylation)/Cyclization Enables Access to Fused Indolo-pyridones

Abstract

A visible-light-initiated radical cascade reaction toward the synthesis of structurally diverse fused Indolo-pyridones is described. The reaction involves the addition of aroyl or sulfonyl radicals to <i>N</i>-alkyl-acryloyl-1<i>H</i>-indole-3-carboxamides, cyclization, and oxidative aromatization. This telescoped method circumvents lengthy prefunctionalization steps of radical precursors, which is further underpinned by the superior compatibility with a series of C-centered radicals, allowing the rapid and facile construction of numerous valuable architectures.