Chemistry Letters, Vol.37, No.6, 628-629, 2008
An unusual reaction of a pyridinium ylide with 1,1-dicyanoethylene derivatives
A reaction of pyridinium perfluorophenacylide generated from pyridinium salt 1 with 1,1-dicyanoethylene derivatives 2 produced unusual products 3, which have an ylide structure with a cyano group at the C2 and a cis-acrylonitrile moiety at the o-position of the perfluorophenyl group. A plausible mechanism involving intramolecular aromatic nucleophilic substitution and 1,3-migration of the cyano group is proposed for this reaction.