Lithium Aluminohydride

Schaeffer, G. W., J. S. Roscoe, and A. G. Stewart The Reduction of Iron(III) Chloride with Lithium Aluminohydride and Lithium Borohydride Iron(II) Borohydride. J. Amer. chem. Soc. 78, 729 (1956). 

Balema, V.P., K.W. Dennis, and V.K. Pecharsky, Rapid solid-state transformation of tetrahedral [A1H4] into octahedral [A1H6]j in lithium aluminohydride, Chem. Commun., 17, 1665, 2000. 

Unlike with sodium borohydride (see Section 11.01.5.2), pyrrolizin-3-one 2 reacts with lithium aluminohydride mainly as an amide. No conjugate addition occurs, and only the reductive lactam cleavage takes place to give stereoselectively the (Z)-allylie alcohol 77. Similarly, benzo-annulated pyrrolizin-3-one 17 gives the corresponding benzylic alcohol 78. The same reactivity was observed with organometallics such as methyllithium which gives exclusively the tertiary (Z)-allylic alcohol 79 (Scheme 7). 

Lithium Aluminohydride. See Aluminum-Lithium Hydride A154-R Lithium Azide A588... 

A simple boron hydrogen compound BH3, does not exist. The electropositivity is too small for a salt-like boride B3+H3, while a sextet configuration would be produced with electron pair bonds. An octet configuration is indeed possible for BH4 in fact the salts Li[BH4] and Na[BH4] exist they have lattice structures similar to NaCl. The well-known LiAlH4, lithium-aluminohydride is also very similar. 

SYNS ALUMINUM LITHIUM HYDRIDE LITHIUM ALANATE LITHIUM ALUMINOHYDRIDE UTHIUM ALUMINUM HYDRIDE pOT) UTHIUM ALUMINUM HYDRIDE, ETHEREAL pOT) LITHIUM ALUMNUM TETRAHYDRIDE... 

Lithium aluminohydride (LiAlH4, LAH) is soluble in ethers. In diethylether and dioxane it forms tight ion pairs, but in THF and in DME it forms loose ion pairs [ADI, WSl]. LAH is used either in solution, as a suspension, or in a solid-liquid phase transfer medium (benzene, 15-crown-5) [DCl, GL4]. It is also used adsorbed onto silica gel [KH2, KH3] however, its reducing power is so diminished under the latter conditions that it can selectively reduce ketoesters to hydroxyesters or amide esters into amide alcohols [ks5]. 

Lithium alanate Lithium aluminohydride. See Lithium aluminum hydride Lithium aluminum hydride CAS 16853-85-3 EINECS/ELINCS 240-877-9 UN 1410 (DOT) UN 1411 (DOT)... 

Synonyms Aluminum lithium hydride LAH Lithium alanate Lithium aluminohydride Lithium aluminum hydride, ethereal Lithium aluminum tetrahydride Lithium tetrahydroaluminate Classification Lithium compd. 

Balema VP et al (2000) Rapid solid-state tiansformatimi of tetrahedral [AlHr] into octahedral [AlHg] in lithium aluminohydride. Chem. Commun 1665-666 Heats of formation and chemical compositions. Purdue School AAE Propulsion Web Page. Available at http //cobweb.ecn.purdue.edu/ propulsi/propulsion/comb/propellants.html. Purdue School of Aeronautics and Astronautics. Accessed 7 Feb 2009 Block J, Gray AP (1965) The thermal decomposition of lithium aluminum hydride. Inorg Chem 4 304-305... 

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