Redox-neutral conversion of ubiquitous P V sources to a versatile PO 2 + phosphorylation reagent

Phosphorus and its compounds are a cornerstone of biological life, as well as finding applications in material science, for example, as flame retardants, battery electrolytes or catalysts. In most applications, phosphorus-containing fine chemicals are in the naturally occurring and most stable oxidation state +V of the element; however, syntheses to these compounds from primary P V sources rely on an energy-consuming and wasteful redox detour via elemental white phosphorus (P 4 ) and its subsequent (oxy)chlorination to PCl 3 , PCl 5 and POCl 3 . Here we report an approach using trifluoromethanesulfonic anhydride (Tf 2 O) and pyridine to directly cleave P–O bonds in ubiquitous P V sources to form the versatile PO 2 + phosphorylation agent (pyridine) 2 PO 2 [OTf] ( 1 [OTf]), whose preparation and mechanism of formation is discussed. Harnessing its reactivity towards various nucleophiles such as amines, alcohols and pseudohalogenides, 1 [OTf] then provides redox-neutral access to a range of value-added P V chemicals downstream of low-cost phosphoric acid or other phosphate sources.