水素化ジイソブチルアルミニウム

外観

無色透明液体～わずかに濁った液体

溶解性

ヘキサン及びベンゼンと任意の割合で混和するが、水及びエタノールには分解する。

解説

水素化ジイソブチルアルミニウム，スイソカジイソブチルアルミニウムC8H19Al(142.22)．[(CH3)2CHCH2]2AlH．略称DIBALH．アルミニウム，イソブテンと水素との反応により得られる．無色の自然発火性の液体．融点－80 ℃，沸点105 ℃(26 Pa)．炭化水素溶媒に可溶．テトラヒドロフランとは錯体を形成する．有機化合物の還元剤として用いられる．

用途

水素化ジイソブチルアルミニウム（すいそかジイソブチルアルミニウム、diisobutylaluminium hydride）は有機合成において汎用される還元剤である。もともとはアルケンを重合させる際の共触媒として開発された化合物である。

使用上の注意

本品を採取する場合は、よく乾燥して窒素を充填した注射器等を用いること。不活性ガス封入

説明

Diisobutylaluminium hydride (DIBALH, DIBAL, DIBAL-H or DIBAH) is a reducing agent with the formula (i-Bu2AlH)2, where i-Bu represents isobutyl (-CH2CH(CH3)2). It can be used for various homogeneous reductions such as alkynes to alkenes, esters or nitriles to aldehydes. It is available commercially as the neat reagent and as a solution in several different solvents (hexane, dichloromethane, tetrahydrofuran, etc.). The neat reagent is a liquid and is supplied in metal cylinders. It is pyrophoric and highly reactive and therefore must be handled with great care. The molar solutions in organic solvents are more stable and easier to handle provided that the normal precautions are taken for working with air-sensitive compounds. They must all be handled in an atmosphere free from oxygen and water. Commonly used solvents for diisobutylaluminium hydride are dichloromethane, diglyme, dioxane and tetrahydrofuran. Even when the substrate is not completely soluble in these solvents successful reductions can be accomplished.

化学的特性

Diisobutylaluminium hydride, also known as Dibal. colorless liquid. Viscosity 18.0mPa-s(25℃). Reacts violently with water to form hydrogen and isobutane. Tetrahydrofuran is not suitable as Dibal solvent, because the two react to produce coordination compounds. Diisobutylaluminium hydride is a useful reducing agent in organic synthesis. It can reduce ketones, carboxylic acids and esters to the corresponding alcohols. Dibal can also reduce lactones to o-hydroxy lactones.

使用

Diisobutylaluminum hydride is commonly used as a reducing agent in organic synthesis.
Diisobutylaluminum hydride can be used in the following protocols:
As a promotor of Tishchenko reaction of aldehydes.
Conversion of benzylidene acetals of 1,2-and 1,3-glycols to the corresponding monobenzyl ethers of the glycols.
To generate a novel chiral reducing agent based on (S)-proline for the asymmetric reduction of prochiral ketones.

安全性プロファイル

Mddly toxic by inhalation. Dangerous fire hazard; iptes spontaneously in air. To fight fire, do not use water, foam, or halogenated extinguisking agents. See also HYDRIDES and ALUMINUM COMPOUNDS.