Designer Lewis acid catalysts - bulky aluminium reagents for selective organic synthesis

Sterically hindered aluminium aryloxides have been developed as designer Lewis acid catalysts for stereo-, regio- and chemo-selective carbon-carbon bond-forming reactions. Compared with classical Lewis acids, these aluminium reagents coordinate strongly with various oxygen-containing substrates, and this coordination is affected by the steric environment of their ligands, The carbonyl groups of the bound substrates are either electronically activated or sterically deactivated depending on the aluminium reagent used and the type of reaction, Designer chiral catalysts based on the structure of these bulky aluminium reagents have also been examined.