Questions: (d) Secondary alkyl halides can undergo SNI and SN2 reactions. If I wish to carry out an SN2 reaction should I use polar protic solvents such as ethanol or polar aprotic solvents such as acetone or tetrahydrofuran, THF?

(d) Secondary alkyl halides can undergo SNI and SN2 reactions. If I wish to carry out an SN2 reaction should I use polar protic solvents such as ethanol or polar aprotic solvents such as acetone or tetrahydrofuran, THF?

Transcript text: (d) Secondary alkyl halides can undergo $S_{N} I$ and $S_{N} 2$ reactions. If I wish to carry out an $S_{N} 2$ reaction should I use polar protic solvents such as ethanol or polar aprotic solvents such as acetone or tetrahydrofuran, THF? Polar Protic

Solution

Solution Steps

Step 1: Understanding $S_N2$ Reaction Mechanism

The $S_N2$ reaction mechanism involves a single step where the nucleophile attacks the electrophilic carbon from the opposite side of the leaving group, leading to a backside attack and inversion of configuration.

Step 2: Solvent Effects on $S_N2$ Reactions

In $S_N2$ reactions, the nucleophile needs to be strong and free to attack the electrophilic carbon. Polar protic solvents, such as ethanol, can form hydrogen bonds with the nucleophile, thereby stabilizing it and reducing its nucleophilicity. This makes the nucleophile less effective in $S_N2$ reactions.

Step 3: Choosing the Appropriate Solvent

Polar aprotic solvents, such as acetone or tetrahydrofuran (THF), do not form hydrogen bonds with the nucleophile. This allows the nucleophile to remain strong and free to attack the electrophilic carbon, making polar aprotic solvents more suitable for $S_N2$ reactions.