Chemoselective synthesis of β-ketophosphonates using lithiated α-(trimethylsilyl)methylphosphonate.

A highly chemoselective synthesis of β-ketophosphonates from pentafluorophenyl esters and lithiated methyl α-(trimethylsilyl)methylphosphonate has been developed. This mild lithiated phosphonate reagent allows the synthesis of functionalized β-ketophosphonates in the presence of unactivated esters with high yields. This method has been compared with the standard lithiated methylphosphonate reagent.