A mechanochemical construction of C–P bonds through radical–radical coupling

Aryl phosphorus compounds are indispensable motifs in organic synthesis, medicinal, and materials chemistry. Herein, we report a robust magnesium-mediated mechanochemical protocol for the room-temperature synthesis of aryl phosphine oxides through direct C-P bond formation. The reaction employs phosphoryl chlorides with aryl or alkyl halides under solvent-minimized milling conditions, providing a broad range of products in moderate to high yields. Preliminary mechanistic investigations suggest that the transformation proceeds through a radical-radical cross-coupling pathway.