Alcohols Organoaluminum reagents

In all of the above processes, the organoaluminum compounds serve as cocatalysts that activate a transition metal for the desired organic transformations. There are several important processes that do not involve transition metals and in which the organoaluminum reagents acts as a catalyst or stoichiometric reagent. The two most important of these are the formation of fatty alcohols and terminal alkenes from ethylene. These capitalize on the Aufbau reaction for formation of alkyl chains that can reach to C200, but the commercially important alkyls are those from C14 to C20 Oxidation of the aluminum alkyl followed by acidic hydrolysis yields predominately C14 to C20 alcohols and alumina (equation 36). The alcohols are converted to... 

Yamamoto and Maruoka investigated the reaction of chiral acetals with organoaluminum reagents. Unprecedented regio- and stereochemical control was observed in the addition of trialkylaluminums to chiral a,/3-unsaturated acetals derived from optically pure tartaric acid diamide [83]. The course of the reaction seemed to be highly influenced by the nature of substrates, solvents, and temperature. These findings provide easy access to optically active a-substituted aldehydes (84), /3-substituted aldehydes (85), a-substituted carboxylic acids (86), or allylic alcohols (87). Because optically pure RJi)- and (5,5)-tartaric acid diamides are both readily available, this method enables the predictable synthesis of both enantiomers of substituted aldehydes, carboxylic acids, and allylic alcohols from a,/3-unsaturated aldehydes (Sch. 54). 

C-3 attack predominantly takes place in the reaction of 2,3-epoxy alcohols with oiganoaluminum compounds such as MesAl, PhCTsdAlEta, MesSKT CAlEta, Bu aAlH and Bu sAl. The yield and stereochemical outcome depend on the substrates and organoaluminum reagents used. ... 

A selective ring-opening of 2,3-epoxy alcohols has been attained with organoaluminum reagents [69,70]. More recently, a highly regio- and stereoselective addition of... 

Organoaluminum reagents are important in Ziegler-Natta catalysts (Section 11.5), but are not widely used in organic synthesis. They can be violently pyrophoric and water-sensitive and can add readily to alkenes. The Aufbau reaction (Eq. 14.15) is a commercial synthesis of C12-C16 linear alcohols that are useful in detergents. 

Yasuda A, Tanaka S, Oshima K, Yamamoto H, Nozaki H (1974) Organoaluminum reagents of type R R NAlEt which allow regiospecific isomerization of epoxides to allylic alcohols. J Am Chem Soc 96 6513-6514... 

Asymmetric induction of chirality is also observed for the diastereoselective addition of organoaluminum reagents and allylstannanes to aldehyde groups at the side chain of Ti -allyl(tricarbonyl)iron lactone complexes. Ketones in the side chain of Ti -allyl(tricarbonyl)iron lactone complexes can be transformed into tertiary alcohols in a diastereoselective fashion by addition of organoaluminum reagents (Scheme... 

Addition of Grignard reagents to ketones to form alcohols is a class of the most fundamental reactions in organic synthesis. Much data on selectivities of this reaction are available. Yamamoto et al. utilized a highly bulky organoaluminum compounds as a... 

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