Diethylaluminium cyanide
| Diethylaluminium cyanide | ||
|---|---|---|
 | ||
| IUPAC name diethylalumanylformonitrile | ||
| Other names Cyanodiethyl Aluminum | ||
| Identifiers | ||
| CAS number | 5804-85-3  | |
| PubChem | 16683962 | |
| Properties | ||
| Molecular formula | C 4H 10AlCN Et 2AlCN | |
| Molar mass | 111.12 g mol−1 | |
| Appearance | dark brown, clear liquid (1.0 mol L−1 in toluene)[1] | |
| Density | 0.864 g cm−3 at (25 °C) liquid | |
| Boiling point | 162 °C / 0.02 mmHg 435.15 K | |
| Solubility in water | Benzene, Toluene, diisopropyl ether | |
| Hazards | ||
| Flash point | 7 °C - closed cup[1] | |
(verify) (what is: / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | ||
| Infobox references | ||
Diethylaluminum cyanide is the organoaluminum compound with formula ((C2H5)2AlCN)n. This compound is usually handled as a solution in toluene. This compound is a reagent for the hydrocyanation of α,β-unsaturated ketones.[1][2][3][4][5]
Synthesis
Diethylaluminum cyanide was originally produced in 1966. It is generated by the treatment of triethylaluminum 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.
- Et3Al + HCN → Et2AlCN + Et-H
Structure
Diethylaluminum cyanide has not been examined by X-ray crystallography, although other diorganoaluminum cyanides have had their crystal structures determined. Diorganylaluminum 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.
A compound similar to diethylaluminum 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:[3]
2CH)2AlCN)3-2D.png)
More recently, bis(hydrocarbyl)aluminium cyanides have been structurally characterized, such as bis(tert-butyl)aluminium cyanide, tBu2AlCN, which forms a tetramer in the crystalline phase:[6][7]
4-2D.png)
Uses
Diethylaluminum cyanide is used for 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.[8] The purpose of this reaction is to generate alkylnitriles which are precursors to amines, amides, carboxylic acids and esters.
References
- ↑ 1.0 1.1 1.2 "MSDS - 276863". Sigma-Aldrich. Retrieved December 9, 2012.
- ↑ Nagata, W. (1966). "Alkylaluminum cyanides as potent reagents for hydrocyanation". Tetrahedron Lett. 7 (18): 1913–1918. doi:10.1016/S0040-4039(00)76271-X.
- ↑ 3.0 3.1 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". Z. Naturforsch. B: Chem. Sci. 59 (11-12): 1214–1222.
- ↑ Uhl, W.; Schütz, U.; Hiller, W.; Heckel, M. (2005). "Synthese und Kristallstruktur des trimeren [(Me3Si)2CH]2Al—CN". Z. Naturforsch. B: Chem. Sci. 60 (2): 155–163.
- ↑ Nagata, W.; Yoshioka, M. (1988), "Diethylaluminum cyanide", Org. Synth.; Coll. Vol. 6: 436
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