S_N2 Reaction: 2^o Benzyl Chloride with HS ^–

Click the structures and reaction arrows in sequence to view the 3D models and animations respectively

The π framework of p orbitals provides stabilisation in the transition state. This improves the rate of the S_N2 reaction and also causes the S_N2 reaction to be favoured over S_N1. Another key aspect of this reaction is the change of configuration at the carbon – from S to R. This is because the nucleophile attacks from behind the leaving group.

For the Animated Molecular Orbital, only one pi bond has been shown on the phenyl ring for simplicity.

Back to more S_N2 reactions

Alternatively, use these links: (Substrate: Nucleophile)

Allyl chloride : SH | Benzyl chloride : SH | 2^o benzyl chloride : SH | 2^o allyl chloride : SH (S_N2′)

R. H. DeWolfe and W. G. Young, Chem. Rev., 1956, 56, 753–901.

J. W. Hill and A. Fry, J. Am. Chem. Soc., 1962, 84, 2763–2769.