Chemistry 2262, section 1
SUMMARY OF MAJOR THINGS TO KNOW FOR THE FINAL
EXAM 1 - EXTENDED SUMMARY
You will need to know the mechanism
for items with an “*”)
IR: recognize characteristic bands for OH, NH, C=O, C-O, C=C, C
H NMR: equivalence of functional groups, splitting pattern (N+1 rule), chemical shifts
depending on substitution (number and electronegativity of substituents). Recognize
characteristic features of
methyl, ethyl, isopropyl,
-butyl groups, aromatic
(various substitutions), vinyl.
Aromaticity = Special Stability from Circular Resonance. Criteria for aromaticity.
Draw Molecular Orbitals using the Polygon Method to determine aromaticity.
Classify compounds as aromatic, antiaromatic, and non-aromatic
Draw resonance structures of aromatic compounds
The more resonance structures you can draw, the more stable the molecule is
Heterocyclic aromatic systems
Only one pair of electrons of a heteroatom are considered, the rest ignored
Everything else is the same
Nomenclature of Mono, Di and Trisubstituted Aromatic Compounds
), Meta (
), Para (
Numerical Order then Alphabetical Order
Electrophilic Aromatic Substitution (EAS); Reactions for Mono-substitution
Side chain reactions (radical benzylic bromination, further transformation of benzyl bromides
(nucleophilic substitution, elimination), permanganate oxidation.
Diazotization of Aminobenzene. Nitrosation of secondary amines (Chapter 15.11)
Sandmeyer and related transformations of aryldiazonium salts (Chapter 15.9)
Transformation of diazonium to F (Schiemann), Cl, Br, I, CN. Hydrolysis and reaction
Regioselectivity in EAS for di- and tri-substitution, substituent effects.
Resonance vs. Inductance (Resonance prevails, only matters for halogens: F, Cl, Br, I)
The most activating substituent determines the site of the attack
Activating and Deactivating effects; Relative order of reactivity of substituted benzene
compounds for EAS.
Synthetic strategies using EAS
Order of adding substituents is important
Anilines do not react in Friedel-Crafts reaction, phenols do react (although slowly, mono-
Using sulfonation-desulfonation and diazotization to introduce substituents into desired
positions (see Problem 19, p. 699, and example on p. 702).
Strongly activating substituents may result in multiple substitution
Friedel-Crafts reaction do not occur with deactivated aromatic substrates (should be at least
as active as Ar-Hal).
Effect of substituents on p
Nucleophilic Aromatic Substitution (NAS).