Selective Functionalization\nof White Phosphorus with\nAlkyl Bromides under Photocatalytic Conditions: A Chlorine-Free Protocol\nto Dialkyl and Trialkyl Phosphine Oxides

A novel and efficient method for the direct selective\nalkylation\nof white phosphorus (P<sub>4</sub>) with alkyl bromides has been developed,\nutilizing 4DPAIPN as the photocatalyst and Hantzsch ester as the reductant.\nThis method facilitates the synthesis of structurally diverse dialkyl\nphosphine oxides in good yields, offering a streamlined alternative\nto the traditional stepwise approach of chlorinating P<sub>4</sub> with Cl<sub>2</sub> and subsequently displacing the chlorine atom.\nNoteworthy features of this reaction include excellent product selectivity,\nremarkable functional group tolerance, and a broad substrate scope.\nAdditionally, this method is effective for the synthesis of trialkyl\nphosphine oxides.