Rank the following compounds in order of their expected...

Rank the following compounds in order of their expected reactivity toward $\mathrm{S}_{\mathrm{N}}^{2}$ reaction:
$$
\mathrm{CH}_{3} \mathrm{Br}, \mathrm{CH}_{3} \mathrm{OTos},\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCl},\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHCl}
$$

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Leaving Group Ability

Leaving group ability is the capacity of a substituent attached to the electrophilic carbon to depart with an electron pair, forming a stable species. In an SN2 reaction, a good leaving group stabilizes the negative charge once it has left the molecule, thereby enhancing the rate of the reaction. Leaving groups such as sulfonates are typically superior to many halides due to their greater stability once they have departed.

Steric Effects

Steric effects refer to the influence of the spatial arrangement of atoms on the reactivity of a substrate. In SN2 reactions, substrates with less steric hindrance, such as primary carbon centers, are more reactive because the nucleophile can more easily access the electrophilic carbon. Conversely, bulky substrates, particularly those with tertiary carbon centers, significantly slow down or even prevent SN2 reactions.

SN2 Reaction Mechanism

The SN2 reaction mechanism is a one-step, bimolecular process where a nucleophile attacks an electrophilic carbon from the rear, leading to a concerted transition state and inversion of configuration. The rate of the reaction depends on both the nucleophile and the substrate concentration, making it sensitive to changes in both steric hindrance and leaving group quality.

Transcript

Please give Ace some feedback