Photocatalytic Arene C–H Amination with Aromatic N-Heterocyclic Radicals

The development of methods to construct C–N bonds directly from abundant C–H centers has been a long-standing interest in the synthesis field, offering expeditious access to a valuable chemical space. Within this context, arene C–H amination represents one of the most appealing and efficient strategies for the synthesis of a diverse range of functionalized aromatic amines. Here, we describe a general approach toward arene C–H amination, which leverages the unique chemistry of photocatalytically generated aromatic N-heterocyclic radicals via a homolytic aromatic substitution mechanism. The broad scope of this reaction renders this technique a powerful tool to streamline the preparation of various medicinally relevant N-arylated heterocycles, enabling late-stage modification of structurally diverse conjugated arenes, drugs, and polymers. Finally, a computational study reveals that the origin of N-site selectivity is postulated to be associated with the localized radical character at the nitrogen center.