Chiral Near‐Infrared Fluorophores by Self‐Promoted Oxidative Coupling of Cationic Helicenes with Amines/Enamines

In one pot, tertiary alkyl amines are oxidized to enamines by cationic dioxa[6]helicene, which further reacts as electrophile and oxidant to form mono or bis donor‐π‐acceptor coupling products. This original and convergent synthetic approach provides a strong extension of conjugation yielding chromophores that absorb intensively in far‐red or NIR domains ( λ max up to 791 nm) and fluoresce in the NIR as well ( λ max up to 887 nm). Intense ECD properties around 790 nm with a |Δ ϵ | value up to 60 M −1  cm −1 are observed.