One-pot synthesis of malononitriles by free radical reactions of ylidenemalononitrile with Et3B and iodoalkane in a water-ether biphase medium

The one-pot synthesis of malononitrile derivatives 4, 6, and 7 in moderate to high yields by the reaction of ylidenemalononitriles 3, prepared in situ from carbonyl compounds 1 and malononitrile 2 in the presence of ammonium acetate in aqueous solution at 50-60 °C, with Et₃B or RI 5/Et₃B in a water-diethyl ether biphase medium under an atmosphere of room temperature is reported. The reaction of Et₃B with adamantyl iodides 8 and 10 under similar conditions gave 9 and 11 in high yields, respectively. However, low yields of the monoalkylated combined with dialkylated malonates 14 were obtained when benzaldehyde 1a was condensed with dimethylmalonate 12 followed by parallel free radical treatment in benzene solution.