Nucleophilic Substitution Flashcards
An SN1 reaction has __ step(s)
2
An SN2 reaction has __ step(s)
1
What is the difference between an SN1 and SN2 reaction?
SN1: The leaving group departs first, then the nucleophile bonds
SN2: The nucleophile bonds at the same time as the leaving group departs
Why is the carbon attacked?
It has a partially positive charge due to electronegativity causing electrons to position closer to the halide (more electronegative)
To be a nucleophile an atom must…
two options
Be negatively charged or neutral, and have a free electron pair
Why do SN2 reactions undergo inversion?
The nucleophile approaches from the back, so the configuration is inverted (R/S S/R)
Which is the rate-limiting step?
The first step, where the leaving group is removed
What type of solvents are favored for SN1 reactions?
Polar protic solvents
What type of solvents are favored for SN2 reactions?
Polar aprotic solvents
What is the difference between products of an SN1 and SN2 reaction?
An SN2 reaction produces an inverted product (Ex. R to S)
An SN1 reaction produces a racemic mixture of S and R (around 50/50)
Which type of carbocation is least and most stable?
Least: Primary
Most: Tertiary
Why do SN1 reactions form a racemic mixture?
The carbocation is achiral, and can be attacked from either the front or back, producing two different products
