Organic Chemistry II

Professor Carl C. Wamser

Chem 335 - Winter 2005

Chapter 12 Skills

Electrophilic Aromatic Substitution

Knowledge - Level 1

Terminology:

activating, deactivating
substituent effects
directing effects
Friedel-Crafts reaction
partial rate factor


Concepts - Level 2

know the general reaction mechanism for electrophilic aromatic substitution

recognize the effect of substituents in stabilizing or destabilizing an intermediate carbocation (activating or deactivating effects)

recognize the directing effects of substituents as a special case of stabilizing or destabilizing an intermediate carbocation (ortho, para- or meta-directors)


Applications - Level 3

identify the various strong electrophiles (and how they are generated) for different electrophilic aromatic substitution reactions:

bromination (Br+ from Br2 + FeBr3)
chlorination (Cl+ from Cl2 + FeCl3)
nitration (NO2+ from HNO3 + H2SO4)
sulfonation (SO3H+ from SO3 + H2SO4)
alkylation (R+ from RCl + AlCl3)
acylation (RCO+ from RCOCl + AlCl3)

be able to generate the resonance forms of an intermediate benzenium ion
(including in the presence of an existing substituent on the ring)

identify expected products from electrophilic aromatic substitution


Analytical Skills - Level 4

classify substituents based on their electron donating or withdrawing characteristics

explain why a given substituent acts as activating or deactivating

explain why a given substituent acts as an ortho, para- director or a meta-director


Synthesis Skills - Level 5

design a synthetic sequence for a given target compound, typically starting from benzene