Synthesis of Phosphinylated Naphthalene Diimides and Radical Anions: A SeT-Mediated Route Circumvents the Use of Metal/Photocatalyst

Phosphinylation of π-scaffolds is of huge current interest; however, the ensuing C-P(O) bond formation necessitates catalyst, light, heat, etc. We report that electron-deficient halogenated naphthalene diimide (NDI) scaffolds can enable catalyst-free, room-temperature phosphinylation via a possible single-eT-mediated reaction. The arylphosphinylated NDIs show multielectron acceptor property, and LUMO of -4.24 eV, rendering the Ph₂PO group equally potent as the electron-withdrawing C≡N group. Thus, in situ reduction can be propelled leading to radical anions and dianions.