Lithium tetramethylpiperidide

Lithium tetramethylpiperidide
Names

IUPAC name Lithium tetramethylpiperidide
Systematic IUPAC name 1-Lithio-2,2,6,6-tetramethylpiperidine
Identifiers
CAS Number	38227-87-1^Y
3D model (JSmol)	Interactive image Interactive image Cyclic tetramer: Interactive image
ChemSpider	21428984^Y
ECHA InfoCard	100.209.926
PubChem CID	11051814
CompTox Dashboard (EPA)	DTXSID00453330
InChI InChI=1S/C9H18N.Li/c1-8(2)6-5-7-9(3,4)10-8;/h5-7H2,1-4H3;/q-1;+1^Y Key: ANYSGBYRTLOUPO-UHFFFAOYSA-N^Y
SMILES [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
Chemical formula	LiC₉H₁₈N
Molar mass	147.19 g·mol⁻¹
Acidity (pK_a)	37
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is ^YN ?) Infobox references

Chemical compound

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]

References

^ amide primer H. J. Reich 2002
^ 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.