Reaction between triphenylphosphine, diaroylacetylenes and arylidenemalononitriles: a novel and simple synthesis of 3-aroyl-2,5-diaryl-2,4-cyclopentadiene-1,1-dicarbonitriles

A novel and simple synthesis of 3-aroyl-2,5-diaryl-2,4-cyclopentadiene-1,1-dicarbonitriles is described. The reactive 1:1 zwitterionic intermediate, formed by the addition of triphenylphosphine to diaroylacetylenes, was trapped by arylidenemalononitriles to produce the title compounds under mild reaction conditions in fairly good yields.