Organoaluminum lithium

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 ... 

EPOXIDES Alumina. r-Butyldimethyl-iodosilane. n-Butyllithium-Magnesium bromide. Cyclohexylisopropylamino-magnesium bromide. Dialkylaluminum amides. lodotrimethylsilane. Lithium l-a,a -dimethyldibenzylamide. Nafion-H. Organoaluminum compounds. Pyri-dinium chloride. Raney nickel. Tti-fluoroacetyl chloride, lrimethylsilyl-acctonitrile. Tris(phenylscleno)borane. Zinc iodide. 

CLAISEN REARRANGEMENT Lithium hex-amethyldisilylazide. Lithium methylsulfi-nylmethylide. Organoaluminum compounds. Sodium melhylsulllnylmethylide. 

Epoxides Cyanotrimethylsilane. Dilithium tetrabromonicklelate. Lithium borohydride. Organoaluminum reagents. Sodium hydrogen telluride. 

DUsobutylaluminum hydride, (CH3)2CHCH2AlCH,CH(CHa)j. Mol. wt. 142.21, b.p, 140°/4 mm. Supplier (i lb. unit in pressure cylinder) Texas Alkyls Inc. (Techn, Bull. Pi 640,928, 1964). Being a liquid, the reagent is dissolved more easily than lithium aluminum hydride. Suitable solvents are ether, benzene, toluene, and cyclohexane. Tetrahydrofurane forms a complex with the hydride and is not suitable. Since the reagent is pyrophoric in concentrated form, all operations with this and other organoaluminum compounds must be conducted in an oxygen-free atmosphere. ... 

The steric and electronic effects of oxygen-substituted ligands attached to aluminum on the tacticity of the polymers were particularly apparent for use of lithium enolate initiator 175 in the presence of organoaluminum catalysts at near-ambient temperature in toluene (Scheme 6.175) [224]. It was demonstrated that the nature of the species R A1(OR) 3 determines the mode of interaction with the lithium enolates and the monomer, which in turn controls the final tacticity of the PMMA. 

The reactivity of the aluminum-carbon bonds is greatly reduced in the 1 1 adducts, and this may be utilized in preparing particularly labile organoaluminum compounds which cannot be isolated in the free form. Thus tri-tert-alkyl alanes, such as tri-terf-butylalane, may be prepared as etherates from tertiary butyl lithium in diethylether (207) or from the corresponding magnesium tertiary alkyls (157, 159) ... 

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