Acylation of α-fluorophosphonoacetate derivatives in the presence of magnesium chloride- triethylamine has been described. Acylations of triethyl α-fluorophosphonoacetate 1 and diethyl α-fluorophosphonoacetic acid 7 were proceeded under mild conditions to provide α- fluoro-β-keto esters 3 and α-fluoro-β-keto phosphonates 9, respectively, in high yields.
[Engman, Mattias; Diesen, Jarle S.; Paptchikhine, Alexander; Andersson, Pher G. Journal of the American Chemical Society, 2007 , vol. 129, # 15 p. 4536 - 4537]