1. Organolithium Compounds
Ionic character
Electron-deficient
Strongly basic
Strongly nucleophilic
Reducing
oligomeric or polymeric structures
applications in
organic synthesis
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Organolithium Compounds

2. Organolithium Compounds
Organo Na, K, ... compounds
"Purely" ionic
Very strong bases
polymeric structures,
mostly insoluble
few applications
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Organolithium Compounds

3. Oligomeric Li compounds: ionic interpretation
Ionic interactions are "soft" but not weak!
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Organolithium Compounds

4. Oligomeric Li compounds: covalent interpretation
2e-3c and 2e-4c bonds
also bonding between the Li atoms
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Organolithium Compounds

5. Organolithium Compounds
[Me3SiCH2Li]6
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Organolithium Compounds

6. Organolithium Compounds
[MeLi·(THF)]4
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Organolithium Compounds

7. Organolithium Compounds
[n-BuLi·(tmeda)]2
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Organolithium Compounds

8. Organolithium Compounds
PhLi
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Organolithium Compounds

9. Organolithium Compounds
PhLi·(pmdta)
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Organolithium Compounds

10. Organolithium Compounds
[PhNa(pmdta)]2
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Organolithium Compounds

11. Organolithium Compounds
(allyl)Li·(pmdta)
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Organolithium Compounds

12. Organolithium Compounds
[2,6-(MeO)2C6H3Li]3
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Organolithium Compounds

13. (napthalene)[Li(tmeda)]2
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Organolithium Compounds

14. Synthesis of Organolithium Compounds
Direct synthesis
Reactivity: alkyl > aryl, Cl < Br < I, Li < Na etc
Side reaction: Wurtz coupling, especially for X = I
In apolar of weakly polar solvents
Radical mechanism
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Organolithium Compounds

15. Synthesis of Organolithium Compounds
Transmetallation
M less electropositive than Li
Infrequently used
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Organolithium Compounds

16. Reactions of Organolithium Compounds
Metallation
Faster for more basic R-
Faster in polar and/or coordinating solvents
Works well if product capable of intramolecular coordination
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Organolithium Compounds

17. Reactions of Organolithium Compounds
Metal-halogen exchange
Facile for I and Br, usually (too) slow for Cl, F
Regioselective synthesis of R'Li
Side reaction: Wurtz coupling
Usually done at low temperature
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Organolithium Compounds

18. Reactions of Organolithium Compounds
Metathesis
Driving force: stability of LiCl (lattice energy!)
Selective synthesis of RlMXm often hard
With excess RLi often "ate" complexes (Rn+1M-)
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Organolithium Compounds

19. Organolithium Compounds
[(tmeda)LiMe2]Mg
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Organolithium Compounds