Reaction of β-trifluoromethyl vinamidinium salt with carbon nucleophiles

1,1,5,5-Tetramethyl-3-trifluoromethyl-1,5-diaza-1,3-pentadienium chloride (β-trifluoromethyl vinamidinium salt) 1 reacted smoothly with various types of enolates generated from ketones and esters to give the corresponding mono-addition–deamination products, dienaminones 2 and dienaminoates 3, respectively, in moderate to good yields. The reaction with carbanions from nitromethane, methyl phenyl sulfone, and acetonitrile also produced the corresponding dienamine derivatives 4, 6 in moderate yields. Interestingly, the carbanion from malononitrile participated well in the reaction with 1 to afford di-addition–deamination product, diisopropylammonium 1,1,5,5-tetracyano-3-trifluoromethyl-1,3-pentadienide (5) in quantitative yield.