Dimethyl 1,1-Dicyanoethene-2,2-dicarboxylate, a New Electophilic Olefin

Article abstract of DOI:10.1021/jo00144a033

Dimethyl 1,1-dicyanoethene-2,2-dicarboxylate (DDED), a new electrophilic tetrasubstituted olefin, was synthesized via Knoevenagel condensation.DDED spontaneously copolymerizes with electron-rich olefins such as styrene and p-methylstyrene.In the copolymerization, the bulky growing styryl radicals add to the dicyano-bearing carbon of DDED.Cyclobutane adducts are obtained in thermal reactions with styrene, p-methylstyrene, p-methoxystyrene and vinyl ethers via a tetramethylene intermediate.Bond formation occurs at diester end of DDED due to the greater stabilization provided by the dicyano group and the minimal steric requirements of the attacking methylene.