Is styrene more activated or more deactivated than benzene towards electrophilic aromatic substitution? The C=C double bond doesn't seem to have any particular electron-withdrawing or -donating properties, so I'm not sure what to make of it.
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$\begingroup$ I guess for many agents the double bond is likely to be attacked first. $\endgroup$– Ivan NeretinMar 9, 2016 at 9:56
1 Answer
Styrene (vinylbenzene) undergoes electrophilic aromatic substitution much faster than benzene. Although the vinyl group seems to be withdrawing, it offers +M effect in the carbocation intermediate. Resonance forms of the intermediates to explain these results. and the products are found to be primarily ortho- and para-substituted styrenes. The products are found to be primarily ortho- and para-substituted styrenes.
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$\begingroup$ Do you have a reference to or example of EAS where the ring reacts rather than the double bond? $\endgroup$ Feb 18 at 16:22