Lithium aluminum hydride is used as a reducing agent in various synthetic organic chemistry reactions. For example, it is used in the conversion of esters, carboxylic acids, acyl chlorides, aldehydes and ketones into their corresponding alcohols. It also involved in the conversion of amide, nitro, nitrile, imine, oxime and azide compounds into their amines as well as reduces alkyl halides to alkanes. It reacts with sodium chloride to prepare sodium hydride. It acts as a potential hydrogen storage medium, which could be used for future fuel cell-powered vehicles. It is mainly used in the preparation of other tetrahydridoaluminumates like sodium aluminum hydride, potassium aluminum hydride and magnesium alanate. Furthermore, it has been used to prepare thermoplastic polyester polyamides from oleic acid and lithium-polymer batteries.
Many procedures for reactions with this reagent which have been described in the literature are potentially unsafe on anything other than a very small scale, since often no precautions are given for mixing the reagent with flammable solvents. The following suggestions are offered for laboratory scale reductions:
Mixing with a flammable solvent must always be carried out under an inert atmosphere.
Reverse addition (solvent to reagent), if done rapidly, may be safer.
For THF, at least 10ml solvent per gram of reagent is recommended to absorb heat of mixing.
Efficient stirring is essential during mixing, reaction and workup.
The use of water or steam baths, or of electric heating mantles is to be strongly discouraged.
The reduction reaction should preferably be controlled by adjusting the rate of addition of the substrate rather than relying on external heating or cooling.
External heating or cooling, if required, should be by means of a suitable inert oil.
The use of Diethoxymethane, B23134 as a reaction solvent has also been recommended.
For phase-transfer reductions in hydrocarbon solvents, see 15-Crown-5, A12265. For formation of lithium tris(diethylamino)aluminum hydride and use in the reduction of esters or amides to aldehydes, see Diethylamine, A11716. For formation of a reagent for reduction of carboxylic acids to aldehydes, see 1-Methylpiperazine, A10837.
For reduction of sulfones, see Titanium(IV) chloride, 14713.
Monograph: J. Seyden-Penne, Reductions by the Alumino- and Borohydrides In Organic Synthesis, 2nd ed., Wiley, N.Y. (1997).
Hsu, C. P.; Jiang, D. H.; Lee, S. L.; Horng, J. L.; Ger, M. D.; Chang, J. K. Buckyball-, carbon nanotube-, graphite-, and graphene-enhanced dehydrogenation of lithium aluminum hydride. Chem. Commun. 2013, 49 (78), 8845-8847.
Gooodman, C. A.; Janci, E. M.; Onwodi, O.; Simpson, C. C.; Hamaker, C. G.; Hitchcock, S. R. A two-step, one pot preparation of amines via acyl succinimides. Synthesis of the calcimimetic agents cinacalcet, NPS R-467, and NPS. Tetrahedron Lett. 2015, 56 (30), 4468-4471.
해저드 설명서 (EU): H260-H314-H318
In contact with water releases flammable gases which may ignite spontaneously. Causes severe skin burns and eye damage. Causes serious eye damage.
주의 설명서: P231+P232-P262-P280-P303+P361+P353-P305+P351+P338-P308
Handle under inert gas. Protect from moisture. Do not get in eyes, on skin, or on clothing. Wear protective gloves/protective clothing/eye protection/face protection. IF ON SKIN (or hair): Remove/Take off immediately all contaminated clothing. Rinse skin with water/shower. IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. IF exposed or concerned: