Arylamine synthesis enabled by a photocatalytic skeletal-editing dehydrogenative aromatization strategy

The construction of aromatic compounds from non-aromatic compounds via skeletal editing is appealing yet challenging in organic chemistry. Herein, we report an approach for the synthesis of site-selective substituted arylamines via a combination of photocatalyzed C–N coupling, skeletal expansion, and dehydrogenative aromatization. A wide variety of primary amines, cyclic and acyclic secondary amines, and iodomethyl cyclopentanones with diverse substitution patterns are suitable for this strategy, providing straightforward access to N,N-dialkyl and N-alkyl arylamines. Notably, free amino alcohols undergo selective N-arylation to deliver N-monoarylated amino alcohols. Mechanistic studies suggested that radical-initiated skeletal rearrangement of cyclopentenyl iminiums followed by selective dehydrogenative aromatization is key to the success of this strategy. We hope this strategy will inspire more effort to build arylamines and other aromatic compounds from non-aromatic systems via skeletal rearrangement.