Aluminium isopropoxide

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Aluminium isopropoxide

General
Systematic name	Aluminium Isopropoxide
Other names	Triisopropoxyaluminium Aluminium isopropanolate Aluminium sec-propanolate Aluminium triisopropoxide 2-Propanol aluminium salt AIP
Molecular formula	C₉H₂₁O₃Al
SMILES	CC(C)O[Al](OC(C)C)OC(C)C
Molar mass	204.25 g/mol
Appearance	white solid
CAS number	555-31-7
Properties
Density and phase	1.035 g/cm³, solid
Solubility in water	Insoluble (decomposes)
Solubility in methanol	Soluble
Melting point	135 °C (408 K)
Boiling point	125-130 °C (198-403 K)
Structure
Crystal structure	monoclinic
Hazards
MSDS	External MSDS
Main hazards	Flammable (F)
NFPA 704	1 2 2
Flash point	16 °C
R-phrases	R11
S-phrases	S8, S16
RTECS number	BD0975000
Supplementary data page
Structure & properties	n, ε_r, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references

Aluminium isopropoxide (C₉H₂₁O₃Al) is a compound of aluminium that is useful in organic chemistry. Aluminium isopropoxide was first used as a reducing agent by Meerwein and Schmeidt in the Meerwein-Ponndorf-Verley reduction in 1925.^[1]

In 1937, Oppenauer used aluminium isopropoxide as an oxidizing agent in a reaction that was essentially the reverse of the MPV reduction.^[2] This reaction is known as the Oppenauer Oxidation.

Aluminium isopropoxide has been also investigated as a catalyst for ring opening polymerization.

1 Preparation
2 Reactions
3 References
4 External links

[edit] Preparation

The most common way of preparing aluminium isopropoxide was published in 1936 by Young, Hartung, and Crossley.^[3] Their procedure entails heating a mixture of 100 g of aluminium wire, 1200 mL of Isopropyl alcohol, and 5 g of mercuric chloride at reflux for seven hours. An catalytic amount of iodine is sometimes now used to initiate the reaction, which can be quite vigorous. Young et al. achieved an 85-90% yield, after purification by distillation at 140-150 °C (5 mm Hg).

[edit] Reactions

In a MPV reduction, ketones and aldehydes are reduced to alcohols concomitant with the formation of acetone. This reduction relies on an equilibrium process, hence it produces the thermodynamic product.

Conversely, in the Oppenauer Oxidation, secondary alcohols are converted to ketones^[4] while homoallylic alcohols are converted to α,β-unsaturated carbonyls.

[edit] References

↑ Meerwein, H.; Schmidt, R. Justus Liebigs Ann. Chem. 1925, 39, 221.
↑ Oppenauer, R. V., Recl. Trav. Chim. Pays-Bas, 56, 137, 1937.
↑ Young, W.; Hartung, W.; Crossley, F. "Reduction of Aldehydes with Aluminum Isopropoxide" Journal of the American Chemical Society, 58, page 100-2, 1936.
↑ Eastham, J. F.; Teranishi, R. "Δ4-Cholesten-3-one" Organic Syntheses, Coll. Vol. 4, p.192 (1963); Vol. 35, p.39 (1955).