Intramolecular Homolytic Substitution Enabled by Photoredox Catalysis: Sulfur, Phosphorus, and Silicon Heterocycle Synthesis from Aryl Halides

Abstract

Aryl radical generation and manipulation constitutes a long-standing challenge in organic synthesis. Photocatalytic single-electron reduction of aryl halides has been established as a premier activation pathway to reach these intermediates. The current study integrates the conceptual simplicity of the classical intramolecular homolytic substitution with the practicality of the modern photocatalytic approach. Predicated on an efficient metal-free dehalogenation of aryl halides under mild organo-photoredox conditions, sulfur, phosphorus, and silicon heteroatoms capture the C(sp²)-centered radical in an intramolecular fashion.