Organophosphorus Synthesis Without Phosphorus Trichloride: The Case for the Hypophosphorous Pathway

The vast majority of organophosphorus compounds is currently synthesized from phosphorus trichloride (PCl3), even though the final consumer products do not contain reactive phosphorus–chlorine bonds. In order to bypass phosphorus trichloride, significant interest has been devoted to functionalizing elemental phosphorus (P4, the precursor to PCl3), red phosphorus (Pred), or phosphine (PH3). Yet, other industrial-scale precursors are hypophosphorous derivatives (H3PO2 and its alkali salts), but their use as phosphorus trichloride replacements has been completely overlooked. Here, the case is made for an alternative approach to the industrial synthesis of organophosphorus compounds based on hypophosphites.