Question

How do you know if a Reaction is $\mathrm{SN}2$?

Answer 1

Conditions by which can estimate the reaction is:

• Rate of reaction -The $\mathrm{SN}2$ reaction$\mathrm{SN}2$ are one step reaction in which bond formation with nucleophile and bond breaking with leaving group done at same time. Thus, the rate of reaction is bimolecular.
• Strong nucleophile and Weak leaving group- A strong nucleophile and weaker leaving group is in the reaction that form bond with substrate and weakens the bond of leaving group.
• Less hindered substrate- The substrate is less hindered for the formation of transition state between strong nucleophile, substrate and leaving group. There is no intermediate formation in $\mathrm{SN}2$ reaction.
• Polar aprotic solvent- The reaction has polar aprotic solvent like DMSO,DMF that dissolve substrate and nucleophile but do not form any bonding with nucleophile.

Thus, We can know the reaction is $\mathrm{SN}2$.