*3.7. General Procedure for the α-Fluorination of β-Keto Ester 9*

Aqueous K3PO4 or other base (2 M, 2 equivalents, 0.1 mL) was added to a mixture of β-keto ester **9** (0.1 mmol, 24.4 mg, ω = 95%) and organocatalyst **I**–**IX** (2 mol%) in toluene or in CH2Cl2 (2 mL) under argon atmosphere. The mixture was cooled to −10°C and NFSI (1.1 equivalents, 34.7 mg) was added in two portions over 2 h. The reaction mixture was stirred for another 12 h at −10 ◦C. After completion, the reaction was quenched by addition of NH4Cl (aq. sat, 4 mL) and extracted with CH2Cl2 (10 mL). The organic phase was dried over anhydrous Na2SO4, filtered, and the volatiles were evaporated in vacuo. The residue was purified by column chromatography (Silica gel 60, EtOAc/*n*-Heptane = 1:15). Enantiomeric excess (ee) was determined by HPLC (Chiralpak AD-H, *n*-Hexane/*i*-PrOH = 200:1, flow rate 0.75 mL/min, λ = 250 nm, 10 ◦C) after isolation by column chromatography.
