[2040-00-8] · C4H10AlI · Diethylaluminum Iodide · (MW 212.01)
(ethylating agent; catalyst)
Alternate Names: diethyliodoaluminum; diethyliodoalane.
Physical Data: bp 118-120 °C/4 mmHg; d 1.609 g cm-3.
Solubility: sol toluene, benzene.
Form Supplied in: colorless liquid; commercially available, either neat or in toluene solution.
Preparative Methods: by reaction of Triethylaluminum and Aluminum Iodide in THF or benzene.1
Handling, Storage, and Precautions: moisture-sensitive and pyrophoric. Reacts with water to form an explosive and flammable gas. Extremely harmful if vapors are inhaled. The reagent is absorbed through skin. Wear gloves. Corrosive. Air-sensitive; must be stored under inert atmosphere. Use in a fume hood.
In using the reagent to deliver the ethyl group to a carbonyl, there appears to be a preference for equatorial attack on cyclohexanones (eq 1).1 A preference was also noted for 1,2-attack over 1,4-attack (eq 2).
An alkylation-deoxygenation reaction provides an interesting approach to substituted alkenes from epoxides (eq 3).2
Diethylaluminum iodide-catalyzed reaction of aldehydes with a,b-unsaturated carbonyl compounds provides a useful entry into molecules of the types shown in eqs 4-7.3
Diethylaluminum iodide is a useful catalyst for conversions of the general type shown in eq 8.4
Bradford P. Mundy
Colby College, Waterville, ME, USA