Diisobutylaluminium hydride

  • DIBAL
  • DIBAL-H
  • DIBAH

Ignite itself, colorless liquid

Liquid

0.79 g · cm -3

-80 ° C

114 ° C (at 1 hPa)

  • Violent reaction with water
  • Insoluble in toluene, hexane, dichloromethane, diethyl ether and THF

Risk

Template: Infobox chemical / molecular formula search available

Diisobutylaluminum hydride ( DIBAL Abbr, DIBAL -H, DIBALH, DIBAH ) is a reducing agent having the chemical formula (i -Bu) 2AlH ( i-Bu = isobutyl ). DIBAL is mainly used in organic synthesis for various reductions and is located in the reactivity between lithium aluminum hydride ( LiAlH4 ) and sodium borohydride ( NaBH4 ).

A typical application of DIBAL is the direct reduction of esters to aldehydes. With LiAlH4 such esters are directly reduced to alcohols, while NaBH4 has no reactivity towards esters.

Also for the reduction of nitriles to aldehydes DIBAL is often used. So that the reaction can be controlled so that a molecule of DIBAL -H always transmits only one hydride ion. Due to the bulky iso -butyl groups sterically accessible electrophilic centers are preferentially attacked.

DIBAL is an electrophilic reducing agent which reacts well with the electron-rich compounds, while the reactivity with respect to electron-deficient substrates is relatively low.

DIBAL is commercially available both in substance, more comfortable, however, in solution (eg, in toluene). It can be synthesized by β -hydride elimination from triisobutylaluminum. DIBAL is air-and moisture-sensitive and reacts violently with water.

CAS registry number Dangerous Substances Directive (67/548/EEC)
235673
de