Alkyl lithium (e.g. n-BuLi, s-BuLi) combines strong nucleophilicity and basicity, key for advanced organic synthesis. Its directed ortho-metalation (DoM) enables highly regioselective functionalization of aromatic rings.
Key Properties
- Strong basicity: deprotonation and carbanion formation;
- Directed metalation: ortho-selectivity via directing groups;
- Low-temperature activity: with ammonia or dry-ice baths for selectivity.
Applications
In pharmaceutical intermediates, alkyl lithium is used for aryl lithiation, halogen-lithium exchange and polymerization initiation, improving purity and yield.
Safety and Storage
Alkyl lithium is pyrophoric with water and air; store and use under inert atmosphere and low temperature with dedicated fire safety.