Lithium tetramethylpiperidide explained

Lithium tetramethylpiperidide (often abbreviated LiTMP or LTMP) is a chemical compound with the molecular formula . It is used as a non-nucleophilic base, being comparable to LiHMDS in terms of steric hindrance.

Synthesis

It is synthesised by the deprotonation of 2,2,6,6-tetramethylpiperidine with n-butyllithium at −78 °C. Recent reports show that this reaction can also be performed 0 °C.^[1] The compound is stable in a THF/ethylbenzene solvent mixture and is commercially available as such.

Structure

Like many lithium reagents it has a tendency to aggregate, forming a tetramer in the solid state.^[2]

See also

• Lithium diisopropylamide
• Lithium amide

Notes and References

1. http://www.chem.wisc.edu/areas/reich/Handouts/lireagents/amidebases.pdf amide primer
2. M.F. Lappert . M.J. Slade . A. Singh . J.L. Atwood . R.D. Rogers . R. Shakir . . 1983 . 105 . 2 . 302–304 . Structure and reactivity of sterically hindered lithium amides and their diethyl etherates: crystal and molecular structures of [Li{N(SiMe₃)₂}(OEt₂)]₂ and tetrakis(2,2,6,6-tetramethylpiperidinatolithium) . 10.1021/ja00340a031.