Diethylaluminium cyanide ("Nagata's reagent")[2] is the organoaluminium compound with formula ((C2H5)2AlCN)n. This colorless compound is usually handled as a solution in toluene. It is a reagent for the hydrocyanation of α,β-unsaturated ketones.[1][3][4][5][6]
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| Names | |
|---|---|
| IUPAC name
diethylalumanylformonitrile
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Other names
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| Identifiers | |
| ECHA InfoCard | 100.024.873 |
PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| (CH3CH2)2AlCN | |
| Molar mass | 111.124 g·mol−1 |
| Appearance | Dark brown, clear liquid (1.0 mol/L in toluene)[1] |
| Density | 0.864 g/cm3 at (25 °C) (liquid) |
| Boiling point | 162 °C (324 °F; 435 K) at 0.02 mmHg |
| Reacts with water | |
| Solubility | Benzene, Toluene, diisopropyl ether |
| Hazards | |
| Flash point | 7 °C (45 °F; 280 K) closed cup[1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis
editDiethylaluminium cyanide was originally generated by treatment of triethylaluminium with a slight excess of hydrogen cyanide. The product is typically stored in ampoules because it is highly toxic. It dissolves in toluene, benzene, hexane and isopropyl ether. It undergoes hydrolysis readily and is not compatible with protic solvents.
- n Et3Al + n HCN → (Et2AlCN)n + n EtH
Structure
editDiethylaluminium cyanide has not been examined by X-ray crystallography, although other diorganoaluminium cyanides have been. Diorganylaluminium cyanides have the general formula (R2AlCN)n, and they exist as cyclic trimers (n = 3) or tetramers (n = 4). In these oligomers, one finds AlCN---Al linkages. One compound similar to diethylaluminium cyanide is bis[di(trimethylsilyl)methyl]aluminium cyanide, ((Me3Si)2CH)2AlCN, which has been shown crystallographically to exist as a trimer with the following structure:[4]
![trimeric bis[di(trimethylsilyl)methyl]aluminium cyanide](/wiki/File:Cyclo-(((Me3Si)2CH)2AlCN)3-2D.png)
Bis(tert-butyl)aluminium cyanide, tBu2AlCN exists as a tetramer in the crystalline phase:[7][8]
4-2D.png)
Uses
editDiethylaluminium cyanide is used for the stoichiometric hydrocyanation of α,β-unsaturated ketones. The reaction is influenced by the basicity of the solvent. This effect arises from the Lewis acidic qualities of the reagent.[9] The purpose of this reaction is to generate alkylnitriles, which are precursors to amines, amides, carboxylic acids esters and aldehydes.
References
edit- ^ a b c "MSDS - 276863". Sigma-Aldrich. Retrieved December 9, 2012.
- ^ Nagata, W (1988). "Diethylaluminum cyanide". Organic Syntheses. VI: 307. doi:10.15227/orgsyn.052.0090.
- ^ Nagata, W. (1966). "Alkylaluminum cyanides as potent reagents for hydrocyanation". Tetrahedron Lett. 7 (18): 1913–1918. doi:10.1016/S0040-4039(00)76271-X.
- ^ a b Uhl, Werner; Schütz, Uwe; Hiller, Wolfgang; Heckel, Maximilian (1995). "Synthese und Kristallstruktur des trimeren [(Me3Si)2CH]2Al—CN". Z. anorg. allg. Chem. 621 (5): 823–828. doi:10.1002/zaac.19956210521.
- ^ Wade, K.; Wyatt, B. K. (1969). "Reactions of organoaluminium compounds with cyanides. Part III. Reactions of trimethylaluminium, triethylaluminium, dimethylaluminium hydride, and diethylaluminium hydride with dimethylcyanamide". J. Chem. Soc.: 1121–1124. doi:10.1039/J19690001121.
- ^ Coates, G. E.; Mukherjee, R. N. (1963). "35. Dimethylaluminium cyanide and its gallium, indium, and thallium analogues; beryllium and methylberyllium cyanide". J. Chem. Soc.: 229–232. doi:10.1039/JR9630000229.
- ^ Uhl, W.; Matar, M. (2004). "Hydroalumination of nitriles and isonitriles" (PDF). Z. Naturforsch. B. 59 (11–12): 1214–1222. doi:10.1515/znb-2004-11-1239. S2CID 99001626.
- ^ Uhl, W.; Schütz, U.; Hiller, W.; Heckel, M. (2005). "Synthese und Kristallstruktur des trimeren [(Me3Si)2CH]2Al—CN" (PDF). Z. Naturforsch. B. 60 (2): 155–163.
- ^ Nagata, W.; Yoshioka, M. (1988). "Diethylaluminum cyanide". Organic Syntheses; Collected Volumes, vol. 6, p. 436.
External links
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