Divergent strategy for the synthesis of original dihydrobenzo- and dihydronaphtho-acridines

Abstract

A straightforward access to numerous novel substituted dihydrobenzo- and dihydronaphthoacridines is described using a unique molecular platform in two key steps. A large range of carbon-based substituents such as aromatic, vinyl, alkynyl fragments through Pd-catalysed couplings has been installed. The molecular diversity is extended to the introduction of aza-heterocycles and further authorizes the installation of alkylamino chains by means of Cu-promoted C–N bond formation. Possible access to quinolinium salts is also described. The methodology revealed convenient preparation of a wide panel of molecules that display various rigidity/flexibility and lipophilic/hydrophilic balances. Finally, the influence of structural modulations on the photophysical properties of these novel architectures is also studied. It is noteworthy that styryl and alkynyl derivatives are emissive in water (ϕ_F up to 12%).