Electrophilic Aromatic Substitution What is Electrophilic Aromatic Substitution? (EAS)

EAS is a substitution reaction in which an atom or group bonded to an aromatic ring is replaced by some other atom or group. The reaction mechanism involves attack of the aromatic ring by an electrophile.

Woah…

Let’s look at a classic example First make Br2 more electrophilic by reacting it with a Lewis acid FeBr3

Now the electrophile is ready to attack a benzene ring, which will result in the formation of an arenium ion:

Capture a nucleophile:

Aromaticity NOT restored!

Rearrangement: Does not change overall reaction product!

Be deprotonated; form pi bond:

Sources: Hardinger, Steven. “Chemistry 14D: Lecture Supplement” 4th Ed. Hayden McNeil. 2016. Print. http://web.chem.ucla.edu/~harding/IGOC/E/electrophilic_aromatic_substitution.html Images used - “Comic Template.” Pinterest, Teachingchannel.org, http://s-media-cache-ak0.pinimg.com/originals/3d/d5/2f/3dd52f68d81487824323f70cbe182a9a.jpg. 06 Nov. 2016. “Jackie Chan Confused.” Someordinarygamers, Fandom Powered by Wikia, 14 Feb. 2015, http://vignette2.wikia.nocookie.net/someordinarygamers/images/4/4a/Jackie-chan-confused.png/revision/latest?cb=20150214001702. 06 Nov. 2016. “Question Rage Face.” Imgflip, Imgflip LLC, https://imgflip.com/s/meme/Question-Rage-Face.jpg. 06 Nov. 2016. “GTFO Guy.” Memegenerator, http://cdn.meme.am/images/9468361.jpg. 06 Nov. 2016. “WOAH kawaii.” Memegenerator, https://cdn.meme.am/images/10024460.jpg. 06 Nov. 2016. “Amazed Face Meme.” Relatably, http://www.relatably.com/m/img/amazed-face-meme/qqwvpinecwltu8ktew9s.png. 06 Nov. 2016 “Grumpy Cat.” Imgflip, Imgflip LLC, https://imgflip.com/s/meme/Grumpy-Cat.jpg. 06 Nov. 2016. “Challenge Denied.” Memecrunch, Rainy Cape S.L., http://memecrunch.com/image/525f315c1605fb3983000001.png?w=400. 06 Nov. 2016. “Computer Guy Meme.” Openclipart, 09 March 2015, https://openclipart.org/image/2400px/svg_to_png/215664/Computer-Guy.png. 06 Nov. 2016. “X All the Things Meme.” Imgflip, Imgflip LLC, https://i.imgflip.com/ohrrn.jpg. 06 Nov. 2016. Disclaimer: I do not own any of the images used. All images belong to their rightful owners.