Aluminum-mediated

Later, Torii et al. found that the tin-aluminum-mediated allylation can be carried out with the less expensive allyl chloride, instead of allyl bromide, when a mixture of alcohol-water-acetic acid was used as the solvent.77 When combined with stoichiometric amounts of aluminum powder, both stoichiometric and catalytic amounts of tin are effective. As reported by Wu et al., higher temperatures can be used instead of aluminum powder.78 Under such a reaction condition, allyl quinones were obtained from 1,4-quinones, followed by oxidation with ferric chloride. Allylation reactions in water/organic solvent mixtures were also carried out electrochemically, with the advantage that the allyltin reagent could be recycled.79... 

Alkyl migration, aluminum-mediated, 3, 279 Alkylphosphines, in Rh-catalyzed hydroformylations dirhodium tetraphosphine, 7, 252 monophosphines, 7, 252 Alkylsilanes... 

Verstraeten SV, Golub MS, Keen CF, et al. 1997. Myelin is a preferred target of aluminum-mediated oxidative damage. Arch Biochem Biophys 344 289-294. 

The aluminum-mediated Petasis-Ferrier rearrangement is a stepwise [1,3]-sigmatropic process. The first step is the coordination of the Lewis-acid to the 0-atom of the enol. Coordination to the ether O-atom is reversible and nonproductive. Cleavage of the adjacent C-O-bond, assisted by the antiperiplanar lone pair of the etheral O-atom, stereospecifically gives rise to an oxocarbenium enolate species, which cyclizes to the desired oxacycle. The rate difference in the rearrangement for the five- versus six-membered series can be explained by the more facile 6-(enolendo)-endo-trig cyclization. The last step is the intramolecular equatorial hydride delivery. 

Gothelf, A. S., Hansen, T., Jorgensen, K. A. Studies on aluminum mediated asymmetric Friedel-Crafts hydroxyalkylation reactions of pyridinecarbaldehydes. J. Chem. Soc., Perkin Trans. 1 2001,854-860. 

Aluminum oxide has been one of the most frequently used reagents for self-condensation of ketones and aldehydes. However applications of aluminum-mediated aldol reactions to cross-coupling have appeared only recently in the literature. Aluminum reagents, in common with other Lewis acids, form aldol product chelates so that unwanted side reactions such as dehydration or secondary condensation may be avoided. ... 

Davies and Liebeskind independently prepared chiral aluminum enolates from enantiomerically homogeneous acyl-iron complexes (137) and recorded the first aluminum-mediated asymmetric aldol reactions. Although the lithium enolate of the chiral iron complex (CHIRAC) provides aldol products with... 

Scheme 45. Aluminum-mediated carbocyclizations Ferrier-type reaction vs. Claisen rearrangement [77]...

Further preparative methods are also based on the reaction of CFsBr or CF3I with TMSCI, consisting in electrochemical - or aluminum-mediated reductive procedures. The need for a more convenient method, avoiding the use of CFsBr because of its ozone depletion potential, has led to the development of a new protocol that employs a magnesium-mediated cleavage of phenyltrifluoromethylsulfoxide (eq 2). 

As shown in Scheme 4.28, the stereocontrolled transformation of l,3-dioxolan-4-ones into substituted tetrahydrofurans involves initial methylenation with dimethyltitanocene 30, subsequent aluminum-mediated rearrangement of the cyclic... 

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