[5804-85-3] · C5H10AlN · Diethylaluminum Cyanide · (MW 111.12)
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.
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.
The preparation of cyanohydrins from ketones and aldehydes of low reactivity can be effected with Et2AlCN (eq 3).4
Takeshi Nakai & Katsuhiko Tomooka
Tokyo Institute of Technology, Japan