Friedel-Crafts Alkylation

The Friedel-Crafts Alkylation reaction is used to add an alkyl group to an aromatic ring in the presence of a strong lewis acid.  This reaction was developed by Charles Fiedel (France) and James Crafts (USA) in 1876, in studying reactions involving the creation of carbon-carbon bonds, some of the most valuable technology in organic chemistry.

This reaction involves taking an aromatic ring and adding an alkyl halide (Cl-R1) with a strong lewis acid (AlCl₃), where the alkyl halide can exist as a tri-substituted, all the way to a methyl.  The chemistry of this reaction involves the AlCl₃ to strip the Cl from the alkyl halide, forming a carbocation (R⁺), followed with the π electrons of the aromatic ring to grab the carbocation. The AlCl₄^- can now strip the H away from the position where the R added on the aromatic ring, reverting the catalyst back to it's original form, and the final product to be formed.