Red-Al, or sodium bisaluminumhydride, is an organoaluminium compound with the formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 NaAlH₂(OC₂H₄OCH₃)₂. The name which is a trademark of Sigma-Aldrich

Sigma-Aldrich

Sigma-Aldrich Corporation , is a life science and high technology company with over 7,600 employees and operations in 40 countries. Its chemical and biochemical products and kits are used in scientific research, biotechnology, pharmaceutical development, the diagnosis of disease, and as key...

 refers to its being a Reducing aluminium compound. It is used almost exclusively as a solution in toluene, which is used as a reagent in organic synthesis

Organic synthesis

Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...

. The compound features tetrahedral aluminium center attached to two hydride

Hydride

In chemistry, a hydride is the anion of hydrogen, H−, or, more commonly, a compound in which one or more hydrogen centres have nucleophilic, reducing, or basic properties. In compounds that are regarded as hydrides, hydrogen is bonded to a more electropositive element or group...

 and two alkoxide

Alkoxide

An alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They can be written as RO−, where R is the organic substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands...

s, the latter derived from 2-methoxyethanol

2-Methoxyethanol

2-Methoxyethanol, or methyl cellosolve, is an organic compound that is used mainly as a solvent. It is a clear, colorless liquid with an ether-like odor. It is in a class of solvents known as glycol ethers which are notable for their ability to dissolve a variety of different types of chemical...

.

Some common functional group reductions using Red-Al can be found below:
Red-Al is a potent hydride reducing agent. It converts carboxylic acid anhydrides and lactone

Lactone

In chemistry, a lactone is a cyclic ester which can be seen as the condensation product of an alcohol group -OH and a carboxylic acid group -COOH in the same molecule...

s to diol

Diol

A diol or glycol is a chemical compound containing two hydroxyl groups A geminal diol has two hydroxyl groups bonded to the same atom...

s. Amide

Amide

In chemistry, an amide is an organic compound that contains the functional group consisting of a carbonyl group linked to a nitrogen atom . The term refers both to a class of compounds and a functional group within those compounds. The term amide also refers to deprotonated form of ammonia or an...

s, nitrile

Nitrile

A nitrile is any organic compound that has a -C≡N functional group. The prefix cyano- is used interchangeably with the term nitrile in industrial literature. Nitriles are found in many useful compounds, one example being super glue .Inorganic compounds containing the -C≡N group are not called...

s, imine

Imine

An imine is a functional group or chemical compound containing a carbon–nitrogen double bond, with the nitrogen attached to a hydrogen atom or an organic group. If this group is not a hydrogen atom, then the compound is known as a Schiff base...

s, and most other organonitrogen compounds are reduced to the corresponding amine

Amine

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

s. Nitroarenes can be converted to azoxyarenes, azoarenes, or hydroazoarenes depending on the reaction conditions.

Comparison with lithium aluminium hydride

As a reagent

Reagent

A reagent is a "substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs." Although the terms reactant and reagent are often used interchangeably, a reactant is less specifically a "substance that is consumed in the course of...

, Red-Al is comparable with LiAlH₄

Lithium aluminium hydride

Lithium aluminium hydride, commonly abbreviated to LAH or known as LithAl, is an inorganic compound with the chemical formula LiAlH4. It was discovered by Finholt, Bond and Schlesinger in 1947. This compound is used as a reducing agent in organic synthesis, especially for the reduction of esters,...

. In contrast with lithium aluminium hydride, Red-Al exhibits good solubility in aromatic solvents. Thus, a 70 wt.%-solution in toluene

Toluene

Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3.It is an aromatic...

is commercially available. Its solutions are also more stable to moisture and air than LiAlH₄ and more thermally stable, tolerating temperatures up to 200 °C. The reagent can be modified to effect partial reductions.

External links

• Red-Al, Sodium bis(2-methoxyethoxy)aluminumhydride at organic-chemistry.org
• Aldrich