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 (JSmol)
ChemSpider
ECHA InfoCard 100.209.926 Edit this at Wikidata
  • InChI=1S/C9H18N.Li/c1-8(2)6-5-7-9(3,4)10-8;/h5-7H2,1-4H3;/q-1;+1 checkY
    Key: ANYSGBYRTLOUPO-UHFFFAOYSA-N checkY
  • [Li]N1C(C)(C)CCCC1(C)C
  • CC1(C)CCCC(C)(C)N1[Li]
  • Cyclic tetramer: CC1(C)CCCC(C)(C)[N+]01[Li-][N+]1(C(C)(C)CCCC1(C)C)[Li-][N+]1(C(C)(C)CCCC1(C)C)[Li-][N+]1([Li-]0)C(C)(C)CCCC1(C)C
Properties
LiC9H18N
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).
checkY verify (what is checkY☒N ?)

Lithium tetramethylpiperidide (often abbreviated LiTMP or LTMP) is a chemical compound with the molecular formula LiC9H18N. 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

References

  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.
Categories