Ch 6 & 7: Haloalkane Reactions (Nucleophilic Substitution and Elimination) Flashcards
Steric Hindrance
Can’t be SN2
1st Degree Carbon
Can’t be SN1 or E1
3rd Degree Carbon
Can’t be SN2
Not an Alkyl Halide
No Reaction
Charged Nucleophile
SN2 or E2
Neutral Nucleophile
SN1 or E1
Protic Solvent
Elimination (only when between SN2 and E2)
Aprotic Solvent
Substitution (only when between SN2 and E2)
Heat added
Elimination (only when between SN1 and E1)
What is a Protic Solvent
A solvent that contains -OH or -NH
Sterically Hindered, Strongly Basic Nucleophile
E2
Base weaker than OH- with a 3rd Degree Substrate
SN1
Base weaker than OH- with a 1st or 2nd Degree Substrate
SN2
Weakly Basic Nucleophile
Substitution
Unhindered, Strongly Basic Nucleophile with CH3 or a 1st Degree Substrate at Low Temp
SN2
What is a Nucleophile?
An electron donor
What is an Electrophile?
An electron acceptor
What kind of displacement is SN2?
Backside
What factors increase Nucleophilic Ability?
Electronegativity of the Nucleophilic Atom, Negative Charge of the Nucleophile, and Basicity of the Nucleophile
Order the Nucleophilicity of the Halogens in Protic Solvents from greatest to least
I, Br, Cl, F
Order the Nucleophilicity of the Halogens in Aprotic Solvents from greatest to least
F, Cl, Br, I
Order the degree of Carbocations from most to least stable
3, 2, 1, 0 (CH3)
What kind of displacement is SN1?
Both Frontside and Backside
How does Carbocation Stability affect SN1 Reaction Rate?
More stability = Faster reaction