Addition of nucleophiles to electron-deficient alkenes: structural studies on the incipient reaction and the zwitterionic intermediate

Three distinct interactions between a Me2N group and an electron-deficient alkene located in the peri positions of a naphthalene ring comprise an almost complete cyclisation, an incipient reaction, and a less favourable orientation of the nitrogen lone pair with respect to the alkene, which can be related to the electronic characteristics of the alkene substituents; the cyclised material is zwitterionic and is composed of the enolate of a beta-dicarboxylic diester and a trialkylarylammonium cation.