Organoaluminum reactions with

Propargylic alcohols are reduced by reaction with lithium aluminum hydride and subsequent hydrolysis to ( J-allylic alcohols via an organoaluminum intermediate (A) as shown below ... 

The regiochemistry of Al-H addition to unsymmetrically substituted alkynes can be significantly altered by the presence of a catalyst. This was first shown by Eisch and Foxton in the nickel-catalyzed hydroalumination of several disubstituted acetylenes [26, 32]. For example, the product of the uncatalyzed reaction of 1-phenyl-propyne (75) with BujAlH was exclusively ds-[3-methylstyrene (76). Quenching the intermediate organoaluminum compounds with DjO revealed a regioselectivity of 82 18. In the nickel-catalyzed reaction, cis-P-methylstyrene was also the major product (66%), but it was accompanied by 22% of n-propylbenzene (78) and 6% of (E,E)-2,3-dimethyl-l,4-diphenyl-l,3-butadiene (77). The selectivity of Al-H addition was again studied by deuterolytic workup a ratio of 76a 76b = 56 44 was found in this case. Hydroalumination of other unsymmetrical alkynes also showed a decrease in the regioselectivity in the presence of a nickel catalyst (Scheme 2-22). 

Organoaluminum compounds, reaction with imino carbocations, 66, 189 Orthoester Claisen rearrangement, 66, 22 Orthoformic acid, triethyl ester, 65, 146 Oxalic acid, diethyl ester, 65, 146... 

Substitution of sulfonesJ Organoaluminum reagents, particularly vinyl- or alkynylalanes, undergo Lewis acid catalyzed substitution reactions with sulfones. Thus the vinylalane 2 reacts with the allylic sulfone 1 in the presence of A1C13 to... 

Organoaluminum reagents, 202 1,1,1-Trifluoroacetone, 323 Trityllithium, 338 Zinc chloride, 349 Stereoselective aldol reactions With boron enolates Boron trichloride, 43 Chlorodimethoxyborane, 73 9-(Phenylseleno)-9-borabicyclo-[3.3.1]nonane, 245 With silyl enol ethers... 

The mechanism of addition of aikylmagnesium halides to double bonds has been the subject of intensive investigation.6 According to the current interpretation, these reactions differ significantly in mechanism from reactions with organoaluminum species under similar reaction conditions. For this reason no general mechanism for can be lormulated carbometallation reactions. 

Reaction with epoxy aiochols-3 Epoxides formed from (E)-allylic alcohols react regioselectively with organoaluminum compounds to provide 1,2-diols with inversion at C j in high yield. 

Organoaluminum compounds, particularly AlEt3, are commercially very important as activators for olefin polymerization catalysts and are produced on a large scale, in spite of their pyrophoric nature and violent reaction with water. In the laboratory organoaluminum compounds can be made from mercury alkyls by transmetallation ... 

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