[pichco]

I was reading recently about the Friedel-Crafts alkylation reaction, used to add (or substitute) an alkyl group on a benzene ring.
The article mentioned that the reaction does not take place if the benzene reactant contained a deactivating group.
Does anyone have an idea why this is?
Is this true of all deactivating groups or just when it comes to especially strong ones, such as nitro groups?  Would cyanobenzene undergo alkylation?

Thank you,
E.

[Albert]

Would cyanobenzene undergo alkylation?

Cyano group is a strong deactivating group.

The article mentioned that the reaction does not take place if the benzene reactant contained a deactivating group.
Does anyone have an idea why this is?

In a nutshell, these functions strongly attract electrons, deactivating benzene ring.

For further information: http://www.cem.msu.edu/~reusch/VirtualText/benzrx1.htm