In summary, we have described an efficient and chemo- selective route to β-ketophosphonates from various penta- fluorophenyl esters. It has been demonstrated that the combination of these activated esters with the lithiated silyl phosphonate reagent 2 provides a highly chemoselective method compatible with substrates containing unactivated esters. Moreover, these transformations proceed in high yields and only require a minimum amount of the lithium reagent 2. This method constitutes an efficient tool for the introduction of a β-ketophosphonate moiety in polyfunctionalized substrates that should find applications in organic synthesis.