Nucleophilic reactions on aromatics

Question 1

Can Nucleophilic substitutions be done directly on an aromatic ring?

Answer 1

No, need to add EWG’s to stabilise the intermediate
e.g substituting PhCl need to nitrate 3 times in order to produce a stable Meisenheimer complex when substituted

Question 2

List some SnAr activating groups that can be added to allow substitution?

Answer 2

1) –NO2
2) –SO2R
3) –CF3
4) –azide
5) –Ketone
6) –Aldehyde

Question 3

diazonium salts can undergo SN1 substitution, what is a diazonium ion?

What are the reagents for its formation?

Answer 3

PhN+—N

PhNh2, HNO2, H2 and heat

Question 4

What reagent reacts with a diazonium ion to give each of the following products?
1) PhCN
2)PhOH
3)PhI
4)PhBr
5)PhCl
6)PhF

Answer 4

1) CuCN
2) H2O
3) KI
4) CuBr
5) CuCl
6) NaBF4

Question 5

Reagents for addition of an amine?

Answer 5

NaNH2, NH3 (l)