Amine α-heteroarylation via photoredox catalysis: a homolytic aromatic substitution pathway

The direct alpha-heteroarylation of tertiary amines has been accomplished via photoredox catalysis to generate valuable benzylic amine pharmacophores. A variety of five- and six-membered chloroheteroarenes are shown to function as viable coupling partners for the alpha-arylation of a diverse range of cyclic and acyclic amines. Evidence is provided for a homolytic aromatic substitution mechanism, in which a catalytically-generated alpha-amino radical undergoes direct addition to an electrophilic chloroarene.