SN2 Effect of Leaving Group

SN2 - Leaving group effect

SN2 reactions experience the same leaving group trends as in SN1 reaction.

TsO- > NH3 > I- >H2O > Br- > Cl- > F- >> HO- > NH2-

 

Take Note

A good leaving group is the conjugate base of a strong acid (i.e. a weak base).  Typically, the best leaving groups are the conjugate base of an acid with a pKa < 0.