Diethylaluminum Cyanide1


[5804-85-3]  · C5H10AlN  · Diethylaluminum Cyanide  · (MW 111.12)

(hydrocyanation of a,b-unsaturated ketones;2 preparation of a-cyanohydrins from carbonyl compounds3)

Physical Data: bp 162 °C/0.02 mmHg; colorless syrup; exists as a tetra- or pentamer in boiling benzene or diisopropyl ether and as a dimer in boiling THF.

Solubility: sol benzene, toluene, diisopropyl ether.

Form Supplied in: solution in toluene.

Preparative Method: by reaction of Triethylaluminum with a slight excess of Hydrogen Cyanide below rt.1

Handling, Storage, and Precautions: highly toxic. It can be stored as 1-2 M solutions in benzene, toluene, or diisopropyl ether. Use in a fume hood.

Hydrocyanation of a,b-Unsaturated Ketones.

Diethylaluminum cyanide is a reagent for the conjugate hydrocyanation of a,b-unsaturated ketones. The reaction is carried out simply by adding a stock solution of the reagent to a solution of the substrate a-enone in an aprotic solvent with ice cooling, and then allowing the reaction mixture to stand at rt (eqs 1 and 2).2,3 This hydrocyanation is reversible and therefore can be controlled both kinetically and thermodynamically; that is, the product is kinetically controlled in the early stage.

Preparation of a-Cyanohydrins from Carbonyl Compounds.

The preparation of cyanohydrins from ketones and aldehydes of low reactivity can be effected with Et2AlCN (eq 3).4

1. Nagata, W.; Yoshioka, M. OR 1977, 25, 255.
2. Nagata, W.; Yoshioka, M.; Hirai, S. JACS 1972, 94, 4635.
3. Agosta, W. C.; Lowrance, W. W., Jr. JOC 1970, 35, 3851.
4. Nagata, W.; Yoshioka, M.; Murakami, M. OS 1972, 52, 96.

Takeshi Nakai & Katsuhiko Tomooka

Tokyo Institute of Technology, Japan

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