Direct catalytic transformation of white phosphorus into arylphosphines and phosphonium salts

Phosphorus compounds are ubiquitous in the chemical sciences, finding applications throughout industry and academia. Of particular interest to synthetic chemists are organophosphorus compounds, which contain P–C bonds. However, state-of-the-art processes for the synthesis of these important materials rely on an inefficient, stepwise methodology involving an initial oxidation of white phosphorus (P4) with hazardous chlorine gas and the subsequent displacement of chloride ions. Catalytic P4 organofunctionalization reactions have remained elusive, as they require multiple P–P bond-breaking and P–C bond-forming events to break down the P4 core, all of which must occur in a controlled manner. Herein, we describe an efficient transition-metal-catalysed process capable of forming P–C bonds from P4. Using blue-light photocatalysis, this method directly affords valuable triarylphosphines and tetraarylphosphonium salts in a single reaction step. The synthesis of organophosphorus compounds from elemental phosphorus is an inefficient process, using multiple steps, stoichiometric metal complexes and/or hazardous reagents such as chlorine gas. Here, a direct photocatalytic route to convert white phosphorus (P4) into phosphines and phosphonium salts is reported.