Silver‐Catalyzed Atom‐Economic Hydrophosphorylation of Propargyl Epoxides: An Access to 4‐Phosphoryl 2,3‐Allenols and Stereodefined 1‐Phosphoryl 1,3‐Dienes

The highly regioselective nucleophilic ring opening of propargyl epoxides by P(O)H compounds based on a silver catalyst is reported. A variety of P(O)H compounds including H‐phosphonates, H‐phosphinates and diarylphosphine oxides can be used to produce 4‐phosphoryl 2,3‐allenols under mild conditions. The stereoselective synthesis of 1‐phosphoryl 1,3‐butadienes from 4‐phosphoryl 2,3‐allenols and organoboronic acids via a palladium‐catalyzed coupling reaction is also described.