Fluorination of White Phosphorus with Fluoride Salts and Quinone Oxidants

We report the synthesis of hexafluorophosphate (PF6–) salts directly from white phosphorus (P4) and simple fluorides MF (M = Li, Na, K, Cs, NMe4) in a single step. The utilization of p-quinones, such as 2,3-dichloro-4,5-dicyano-1,4-benzoquinone (DDQ) offers a selective fluorination pathway, which affords MPF6 salts in up to 95% yield in acetonitrile (MeCN). NMR investigations of the DDQ-mediated P4 fluorination reaction revealed the formation of PF3 and PF5·MeCN as key reaction intermediates. Donor–acceptor interactions between DDQ and fluoride are critical, effectively increasing the fluoride concentration and enabling efficient fluorination to PF6–. Tetraethylene glycol (TEG) selectively stops the reaction at the adduct K[PF5·TEG]. In contrast, noncoordinating dichloromethane (DCM) favors PF3 formation by suppressing EDA interactions through low fluoride solubility, possibly via the tris(hydroquinonyl)phosphite P(DDQH)3, underscoring the critical role of fluoride solubility. This work demonstrates that quinone–fluoride interactions can be exploited for oxidative fluorination chemistry, establishing a new conceptual framework for P4 fluorination.