Powerful Bispyridinylidene Organic Reducing Agents with Iminophosphorano π‐Donor Substituents

Four members of a new family of powerful bispyridinylidene organic reducing agents have been prepared, which exploit iminophosphorano (?N=PR₃; R=Ph, Cy) π‐donor substituents. Electrochemical studies show exceptionally high oxidation potentials, ranging from 1.30 to 1.51 V versus SCE. These new reductants were shown to effectively convert 1‐bromonaphthalene to naphthalene under mild reaction conditions. From the redox potentials, substituent constants (σ_p⁺) for the iminophosphorano groups Ph₃P=N? (?1.82) and Cy₃P=N? (?2.21) were determined, demonstrating their superior π‐donating properties compared to traditional amino substituents.