When performing a FriedelCrafts alkylation reaction not only

When performing a Friedel-Crafts alkylation reaction, not only does one have the problems of multiple alkylation and rearrangement of the cation, but the presence of strong electron donating groups(yes, donating is correct) prevents reaction. Provide an explanation for this.

Solution

strong electron donating groups on the benzene ring will be attacked by the lewis acid and form a complex which will deactivate the lewis acid and the benzene ring because of the cation that they form..

MeO-Ph + AlCl3 ---> Me(Ph)O-AlCL3-
H2NPh + BCl3 ---> H2N(BCl3)Ph-