NEET2019ChemistryGeneral Organic ChemistryActual
Which can not behave as a nucleophile for S _ N 2 reaction?
Options
- AH ₂ O
- BCN ⁻
- CNH ₂⁻
- DI⁻
Correct answer
A. H ₂ O
Step-by-step solution
In S _ N 2 reaction, nucleophile transfers electron pair to carbon of substrate, leading to the formation of transition state. H ₂ O is a neutral nucleophile while CN ⁻, NH ₂⁻ and I ⁻ are negatively charged nucleophile. Thus, H ₂ O cannot behave as a nucleophile for S _ N 2 reaction.