Organic Chemistry I: Catalysts & Directing Effects

-NR3 (+)

Strongly deactivating, meta-directing

-NO2

Strongly deactivating, meta-directing

-SO3H

Deactivating, meta-directing

C triple bonded to N (-CN)

Deactivating, meta-directing

COOH

Deactivating, meta-directing

COCH3

Deactivating, meta-directing

COOCH3

Weakly deactivating, meta-directing

COH

Weakly deactivating, meta-directing

-Br

Deactivating, ortho/para-directing

-I

Deactivating, ortho/para-directing

-F

Deactivating, ortho/para-directing

-Cl

Deactivating, ortho/para-directing

-CH3 (alkyl)

Weakly activating, ortho/para-directing

Toluene

Weakly activating, ortho/para-directing

-OCH3

Activating, ortho/para-directing

-NHCOCH3

Activating, ortho/para-directing

-OH

Strongly activating, ortho/para-directing

(second strongest), EDG

-NH2

Strongly activating, ortho/para-directing

(slightly stronger than -OH), EDG

What does it mean for a substituent to be activating?

They make the benzene ring more reactive (nucleophilic), and the reactions are bigger and faster.

What does it mean for a substituent to be deactivating?

They make the benzene ring less reactive (electrons are pulled away from the ring center), and the reactions are smaller and slower.

What type of attack has the lowest activation energy?

Para attack

What type of attack has the highest activation energy?

Meta attack

What type of attack has the second lowest activation energy?

Ortho attack

Halogenation of benzene catalysts: bromination

Br2 + AlBr3 or FeBr3

Halogenation of benzene catalysts: chlorination

Cl2 + AlCl3 or FeCl3

Nitration of benzene: catalysts

HNO3 + H2SO4

Sulfonation of benzene: catalysts

SO3 + H2SO4 or fuming H2SO4

Friedel-Crafts alkylation of benzene: catalyst

AlCl3

Acid-promoted alkylation of benzene: catalyst

H2SO4

Friedel-Crafts acylation of benzene: catalyst

AlCl3

What pair of atoms is required for side chain oxidation, and in what position?

A C-H bond in the benzylic position (next to ring)

Name two strong reagents needed for side chain oxidation.

KMNO4 and Na2Cr2O7

What is the substituent change in side chain oxidation?

A carbon side chain is converted into carboxylic acid (COOH)

What is always the product of side chain oxidation, regardless of how long the side chain is?

Benzoic acid

A side chain reaction using KMnO4 needs what other compound to react?

Acid, like H3O+

A side chain reaction using sodium dichromate (Na2Cr2O7) needs what other compound to react?