During an electrophilic aromatic substitution, the aromatic pi cloud interacts with an electrophile to form an arenium ion (AKA sigma-complex). The following image (from my organic chemistry class) suggests that aromaticity is always restored and that a nucleophile can't interact with the resonanced carbocation of the arenium ion.
If I were to replace the base in the above image with a nucleophile that is an extremely poor base (such as iodine), could the nonaromatic cyclodiene be formed? Or would the reaction just halt instead?
Follow up question: If electrophilic aromatic subsitution doesn't work, how would one go about making the cyclodiene (with Nu and E substituents) from an arene? Is it possible?