Metal-catalysed carbon-carbon bond formation in the reaction of malononitrile with beta-dicarbonyls

Nickel acetylacetonate effectively catalyses the carbon-carbon bond formation between malononitrile and beta-dicarbonyls. In these metal-catalysed reactions malononitrile behaves as an electrophile towards the intercarbonylic carbon, so exhibiting a reverse reactivity compared with that one under basic or thermal conditions. The resulting organic products are beta-cyanomethylene-beta-enamino dicarbonyls (2a-h), which are obtained in good-to fair yield. beta-Iminodicarbonyl complexes of nickel(II) and copper(II), which are likely intermediates in the catalytic cycle, are synthesised by reaction of the metal beta-carbonylenolate with malononitrile or of the metal acetate with the catalysis product (2a, d).