Base‐Promoted Synthesis of β‐Ketophosphine Oxides from Diphenylphosphorylallenes

The transition-metal-free synthesis of beta-ketophosphine oxides from diphenylphosphorylallenes in the presence of pyrrolidine and silica gel has been developed under mild reaction conditions. This simple and efficient transformation tolerates a wide range of diphenylphosphorylallenes with different functional groups, and affords the desired products in moderate to excellent yields.