Allylpotassium

Allylpotassium

Names
IUPAC name Potassium prop-2-en-1-ide
Other names Potassium prop-1-ene Potassium 2-Propenyl Allylpotassium Potassium allyl
Identifiers
CAS Number	7329-38-6
3D model (JSmol)	Interactive image
ChemSpider	35786254
PubChem CID	12859842
CompTox Dashboard (EPA)	DTXSID50511691
InChI InChI=1S/C3H5.K/c1-3-2;/h3H,1-2H2;/q-1;+1 Key: ZPQJASJRBFXYKB-UHFFFAOYSA-N
SMILES [K+].[CH2-]C=C
Properties
Chemical formula	C3H5K
Molar mass	80.171 g·mol−1
Appearance	colorless solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Allylpotassium is an organopotassium compound with the molecular formula CH₂=CHCH₂K. It is a colorless, extremely air-sensitive compound that is usually generated and handled in solution. It is synthesized by metalation of propylene with Schlosser's base, a mixture of potassium tert-butoxide and butyl lithium: ^[1]

CH₂=CHCH₃ + LiC₄H₉ + KOC(CH₃)₃ → KCH₂CHCH₂ + C₄H₁₀ + LiOC(CH₃)₃

Consistent with its extreme air-sensitivity, allylpotassium is highly nucleophilic. ^[2] For example, it adds to pyridine, allowing the synthesis of 4-allyl-1,4-dihydropyridines. ^[3] Trimethylsilyl-substituted allylpotassium have been characterized by X-ray crystallography ^[4]

Further reading

• Giner, J. L., Margot, C., & Djerassi,C (April 1989). "Scope and regiochemical control of the allylpotassium reaction in the synthesis of sterols with unsaturated side chains" . The Journal of Organic Chemistry. 54 (9): 2117–2125. doi:10.1021/jo00270a021.
• Thompson, T. B., & Ford, W. T. (September 1979). "Rotational barriers of allyl anions in solution" . Journal of the American Chemical Society. 101 (19): 5459–5464. Bibcode:1979JAChS.101.5459T. doi:10.1021/ja00513a001.

References

1. Schlosser, M. (1974). "Prescriptions and Ingredients for Controlled CC Bond Formation with Organometallic Reagents. New synthetic methods". Angewandte Chemie International Edition in English. 13 (11): 701–706. doi:10.1002/anie.197407011.
2. Zhang, X., Fensterbank, L., & Chauvier, C. (15 December 2023). "Silylation of Allylic C(sp³ )–H Bonds Enabled by the Catalytic Generation of Allylpotassium Complexes" . ACS Catalysis. 13 (24): 16207–16214. doi:10.1021/acscatal.3c04626.
3. Schlosser, M (1 January 1988). "Superbases for organic synthesis". Pure and Applied Chemistry. 60 (11): 1627–1634. doi:10.1351/pac198860111627.
4. Sulway, S. A., Girshfeld, R., Solomon, S. A., Muryn, C. A., Poater, J., Solà, M., Bickelhaupt, F. M., & Layfield, R. A. (September 2009). "Alkali Metal Complexes of Silyl-Substituted ansa -(Tris)allyl Ligands: Metal-, Co-Ligand- and Substituent-Dependent Stereochemistry" . European Journal of Inorganic Chemistry (27): 4157–4167. doi:10.1002/ejic.200900618.