Photoredox Catalysis toward 2‑Sulfenylindole Synthesis through a Radical Cascade Process

A radical
cascade process initiated through visible-light induced thiyl radical
coupling with ortho-substituted arylisocianides followed
by an intramolecular cyclization and subsequent aromatization to access
2-sulfenylindoles is described. The key thiyl radicals are promptly
generated via a hydrogen atom transfer event. The redox-neutral protocol
features broad substrate scope, excellent functional group tolerance,
and mild reaction conditions. Furthermore, the implementation of a
continuous flow variant allows smooth scalability with a short residence
time through process intensification.