Lithium tetramethylpiperidide

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Lithium tetramethylpiperidide
Structural formula of lithium tetramethylpiperidide
Names
IUPAC name
Lithium tetramethylpiperidide
Systematic IUPAC name
1-Lithio-2,2,6,6-tetramethylpiperidine
Identifiers
3D model (Jmol)
ChemSpider
ECHA InfoCard 100.209.926
Properties
C9H18LiN
Molar mass 147.19 g·mol−1
Acidity (pKa) 37
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Lithium tetramethylpiperidide (often abbreviated LiTMP or LTMP) is a chemical compound with the molecular formula C9H18LiN. It is used as a non-nucleophilic base, being comparable to LiHMDS in terms of pKa and steric hindrance.

Synthesis[edit]

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 commercially available as such.

Structure[edit]

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

Lithium tetramethylpiperide tetramer.jpg

See also[edit]

References[edit]

  1. ^ amide primer H. J. Reich 2002
  2. ^ M.F. Lappert; M.J. Slade; A. Singh; J.L. Atwood; R.D. Rogers; R. Shakir (1983). "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)". Journal of the American Chemical Society. 105 (2): 302–304. doi:10.1021/ja00340a031.