Mechanochemistry-Enhanced Regioselective Hydrophosphinylation of Acrylamides and Enamides

Herein, we report a ball milling technique for the regioselective hydrophosphinylation of acrylamides and enamides, utilizing readily available Ph₂PCl as the phosphine source and H₂O as an additive under metal-free and toxic solvent-free conditions. Michael-type and Markovnikov hydrophosphinylation reactions have been achieved for acrylamides and enamides, respectively. The reaction features broad substrate scope, sustainable conditions and high atom economy, facilitating the rapid assembly of structurally diverse amide-based phosphine oxides in useful to good yields.