Leaving Group
| Also Known As | Nucleofuge, departing group, expelled group (in nucleophilic substitution) |
|---|
What is Leaving Group?
A leaving group is an atom or group of atoms that departs with the bonding electrons during a substitution or elimination reaction. Good leaving groups are stable when they leave as anions or neutral molecules. The ability of a group to leave is related to its stability as an anion (weak bases make good leaving groups). Common leaving groups include halides (Cl⁻, Br⁻, I⁻), tosylate (OTs⁻), mesylate (OMs⁻), and water (H₂O).
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
A leaving group is an atom or group of atoms that departs with the bonding electrons during a substitution or elimination reaction. Good leaving groups are stable when they leave as anions or neutral molecules. The ability of a group to leave is related to its stability as an anion (weak bases make good leaving groups). Common leaving groups include halides (Cl⁻, Br⁻, I⁻), tosylate (OTs⁻), mesylate (OMs⁻), and water (H₂O).
Organic synthesis planning (choosing optimal leaving group). SN1 and SN2 reaction design. Elimination reactions (E1, E2). Enzyme mechanisms (serine proteases use OH converted to leaving group). Pharmaceutical synthesis. Drug metabolism understanding.
Safety depends on specific leaving group and substrate. Alkyl halides: many are toxic and/or carcinogenic. Tosylates and mesylates: reactive with nucleophiles — handle as alkylating agents. Some are skin/mucous membrane irritants.