Chapter 5 - Aromatic Compounds
New Skills
Knowledge - Level 1
know the terminology:
special names for substituted benzenes
(toluene, phenol, aniline, benzaldehyde, benzoic acid, benzonitrile,
the xylenes - o,m,p, phenyl group, benzyl group)
special names for other aromatic compounds:
(furan, pyrrole, pyridine, naphthalene, anthracene)
know the nomenclature rules for aromatic compounds
ortho, meta, para for disubstituted benzenes
Concepts - Level 2
recognize the special characteristics of aromatic compounds:
delocalized cyclic pi system with (4n+2) electrons (i.e., 2, 6, 10, ....
)
structure is NOT alternating double and single bonds
(all C-C bonds in benzene are equivalent)
cyclic structure may include heteroatoms
very stable and unreactive compared to other unsaturated compounds
reactions usually lead to substitution, not addition
know the general reaction mechanism for electrophilic aromatic substitution
recognize the effect of substituents in stabilizing or destabilizing the
intermediate carbocation (activating or deactivating effects)
recognize the directing effects of substituents as a special case of stabilizing
or destabilizing the intermediate carbocation (ortho, para- or meta-directors)
understand the benefits of retrosynthetic analysis for designing a reaction
sequence
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)
recognize oxidation and reduction reactions of aromatic compounds
be able to generate the resonance forms of an intermediate benzenium ion
(including in the presence of an existing substituent on the ring)
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
Synthetic Skills - Level 5 & higher
design a synthetic sequence for a given target compound, typically starting
from benzene