Aluminium triisopropoxide

Full details on this ring opening46 under titanium tetraisopropoxide or aluminium triisopropoxide catalysis have been published. Using chirally modified titanium catalysts, cyclohexene oxide provides47 fraws-2-azidocyclohexanol in up to 63% ee. 

The Oppenauer oxidation with aluminium alkoxides provides an alternative method for the oxidation of secondary (and less commonly primary) alcohols. The reaction is the reverse of the Meerwein-Pondorff-Verley reduction (see Section 7.3). Typically aluminium triisopropoxide (or aluminium tri-tert-butoxide) is used, which serves to form the aluminium alkoxide of the alcohol. This is then oxidized through a cyclic transition state at the expense of acetone (or cyclohexanone or other carbonyl compound). By use of excess acetone, the equilibrium is forced to the right (6.45). 

Duda, A., and S. Penczek. 1995. On the difference of reactivities of various aggregated forms of aluminium triisopropoxide in initiating ring-opening polymerizations. Macromolecular Rapid Communications 16(1) ... 

The Cr catalysts were prepared by the incipient-wetness method with chromium(VI)oxide (CrOj) (UCB) onto alumina and silica. The chromium loading was 0.2 wt%. Silica and alumina were prepared by the sol-gel method starting from respectively TEOS and Al(iP)3 and H2O, followed by titration. The obtained gels were dried, calcined and crushed. Details about the preparation method and the characteristics of the materials were published elsewhere [13,14] (TEOS = tetraethyl orthosilicate, Al(iP)j = aluminium triisopropoxide). 

Kurokawa, H., Ohshima, M., Sugiyama, K., and Miura, H. (2003) Methanolysis of polyethylene terephthalate (PET) in the presence of aluminium triisopropoxide catalyst to form dimethyl terephthalate and ethylene glycol. Polymer Degradation and Stability, 79 529-533. 

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