Propynyllithium
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| Names | |
|---|---|
| IUPAC name
1-Lithium-1-propyne
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| Other names
1-Propyn-1-yllithium
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.022.604 |
| EC Number |
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PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| C3H3Li | |
| Molar mass | 46.00 g·mol−1 |
| Appearance | Whitish powder |
| Decomposition | |
| Hazards | |
| GHS labelling: | |
 
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Propynyllithium is an organolithium compound with the chemical formula LiC
2CH
3. It is a white solid that quickly decomposes upon contact with air or water. It is soluble in 1,2-dimethoxyethane, and tetrahydrofuran. To preclude degradation by oxygen and water, propynyllithium and its solutions are handled under inert gas (Ar or N
2).[1]
Synthesis
Various preparations of propynyllithium are known, but the most expeditious route starts with 1-bromopropene:[2][3]
- CH3CH=CHBr + 2 BuLi → CH3C2Li + 2 BuH + LiBr
Historic routes
It can be prepared by passing propyne gas through a solution of n-butyllithium[4] or by direct metallization of propyne with lithium in liquid ammonia or other solvent. Propyne, however, is an expensive gas, and, therefore, it is sometimes replaced by less expensive gas mixtures used for welding and containing a small percentage of propyne.
Applications
Propynyllithium is used in the organic synthesis as a reactant.[2][5] It is a nucleophile that adds to aldehydes to give secondary alcohols, with ketones to give tertiary alcohols, and with acid chlorides to give ketones containing the propynyl group. These reactions are used in the synthesis of complex natural and synthetic substances such as the drug mifepristone.[6]
References
- ^ Greeves, Nicholas (15 April 2001). "Propynyllithium". onlinelibrary.wiley.com. doi:10.1002/047084289X.rp277. Retrieved 17 May 2017.
- ^ a b "Synthesis of 1-Iodopropyne". Org. Synth. 93: 245. 2016. doi:10.15227/orgsyn.093.0245.
{{cite journal}}: Cite uses deprecated parameter|authors=(help) - ^ Toussaint, Dominique; Suffert, Jean (1999). "Generation of 1-Propynyllithium From (Z/E)-1-Bromo-1-propene: 6-Phenylhex-2-yn-5-en-4-ol". J. Org. Chem. vol. 60: 3550–3553.
{{cite journal}}:|volume=has extra text (help) - ^ "Acetylenic lead compounds and gasoline compositions thereof US 3185553 A". Retrieved 17 May 2017.
- ^ "Acetylenic lead compounds and gasoline compositions thereof US 3185553 A". Retrieved 17 May 2017.
- ^ Hazra, B.G.; Pore, V.S. (2001). "Mifepristone (RU-486), the recently developed antiprogesterone drug and its analogues". Journal of the Indian Institute of Science. vol. 81: 287–298.
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