Place a ethyl cyanoacetate (0.5 mmol), DMF (1 mL) and phase transfer catalyst (0.05 mmol) in a Schlenk tube equipped with magnetic stirring bar and a rubber septum. Deaerate the mixture three times by evacuation and refill with argon (in the case of CH2Cl2, evacuation is carried out with care, boiling of the solvent being controlled). Add Pd(dba)2 (6 mg, 0.01 mmol) and a phosphordiamidite ligand (0.04 mmol) to the mixture. Stir the mixture until the color changes from dark-red to yellow. Add an allyl acetate (1.25 mmol) to a stirred mixture. After 10 minutes, add potassium carbonate (2 mmol) to the mixture. Evacuate the Schlenk tube and refill with argon. Stir the mixture for 18 hours at ~20 °C (GC monitoring; in most cases, the reaction completed in 5-6 hours). For the GC analysis, treat an aliquot with water. Extract the mixture with diethyl ether. Isolate the product. Dry the extract with Na2SO4. Concentrate the extract in vacuo. Purify the ethyl 2-cyanopent-4-enoate by column chromatography of the residue (SiO2, eluent-gradient of EtOAc in petroleum ether, 0 → 5%).
