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Chapter 3
Important Concepts and Principles
Ch 3.1:
Substitution, Addition, Elimination, Rearrangement
Reaction mechanism, Hetrolytic/homolytic bond cleavage
Ch 3.2:
Brønsted-Lowry and Lewis definition of acid/base
Conjugate acid/base
Ch 3.3-4: Carbocation and carbobanion, the use of curved arrows
Ch 3.5-11: Strength of acid/base (Ka and pKa) and its prediction
Effect of hybridization on acidity, Inductive/Resonance effect
Equilibrium constant (Keq), Standard free-energy change (ΔG°)
Ch 3.12-14: Protonation on lone pair electrons (alcohols, amines, ethers,
carbonyl compounds), Mechanism for organic reactions
Acid/base reaction in nonaqueous solution, leveling effect
Chapter 3
Suggested Problems
Ch 3.2:
Brønsted-Lowry and Lewis definition of acid/base
Conjugate acid/base
Problem 3.1, 3.2, 3.15–3.19
Ch 3.3-4: Carbocation and carbobanion, the use of curved arrows
Problem 3.3, 3.20, 3.31
Ch 3.5-11: Strength of acid/base (Ka and pKa) and its prediction
Effect of hybridization on acidity, Inductive/Resonance effect
Equilibrium constant (Keq), Standard free-energy change (ΔG°)
Problem 3.4–3.11, 3.22–3.25, 3.27–3.29, 3.33–3.34, 3.36
Ch 3.12-14: Protonation on lone pair electrons (alcohols, amines, ethers,
carbonyl compounds), Mechanism for organic reactions
Acid/base reaction in nonaqueous solution, leveling effect
Problem 3.13
Categories of Organic Reactions
Substitutions:
one group replaces another
Additions:
two molecules becomes one
Eliminations:
one molecule loses the elements of another
Rearrangement:
Reorganization of a molecule’s
constituent parts
What’s common in these reactions?
Covalent bond cleavage:
Heterolytic bond cleavage requires
polarized bond
Heterolytic bond cleavage often
requires external assistance
Acid–Base Reaction
Why acid–base?
Many reactions in organic chemistry are:
either acid–base reaction themselves
or involves acid–base reaction at some stage
Brønsted-Lowry definition:
Acid – a substance that can donate (or lose) a proton
Base – a substance that can accept (or remove) a proton
Acid–base reaction of other
strong acids
Acid–Base Reaction
Lewis definition:
Acid – an electron pair acceptor
Base – a an electron pair donor
Other examples of
Lewis acid–base reaction
Acid–Base Reaction
Lewis definition:
H
F
F
B
Acid – an electron pair acceptor
Base – a an electron pair donor
+
F
N
H
F
H
H
B N H
F
H
F