Tf ₂ O-Mediated Phospha-Michael Addition to Unactivated α,β-Unsaturated Amides

Tf₂O-mediated phospha-Michael addition to unactivated α,β-unsaturated amides has been developed under mild, metal-free conditions, providing efficient access to γ-aminophosphine oxides with excellent regioselectivity. This protocol features a broad substrate scope and good functional group tolerance, accommodating a range of electron-rich, electron-deficient, and base-sensitive groups such as methoxyl, nitro, cyano, ester, and carboxylic acid groups. Primary, secondary, and tertiary amides, as well as structurally complex acrylamides derived from bioactive molecules, are compatible, affording the phosphorylated amides in moderate to excellent yields.