Alkylmetal reagents

For the copper-catalyzed 1,4-addition to 2-cyclohexen-l-one, other alkylmetal reagents have also been employed, achieving high enantioselectivity in some cases [Eqs. (3.2)-(3.4)]. Recently, one example appeared that utilized diphenylzinc as the nucleophile in the presence of phosphoramidite ligand 1 to produce highly enantio-enriched 3-phenylcyclohexanone [Eq. (3.5) 94% ee]. ... 

Metal-catalyzed Multicomponent Reactions 8.8.2.2 Alkylmetal Reagents... 

Aromatic carboxylic acids, a,/f-unsaturated carboxylic acids, their esters, amides, aldehydes and ketones, are prepared by the carbonylation of aryl halides and alkenyl halides. Pd, Rh, Fe, Ni and Co catalysts are used under different conditions. Among them, the Pd-catalysed carbonylations proceed conveniently under mild conditions in the presence of bases such as K2CO3 and Et3N. The extremely high toxicity of Ni(CO)4 almost prohibits the use of Ni catalysts in laboratories. The Pd-catalysed carbonylations are summarized in Scheme 3.9 [215], The reaction is explained by the oxidative addition of halides, and insertion of CO to form acylpalladium halides 440. Acids, esters, and amides are formed by the nucleophilic attack of water, alcohols and amines to 440. Transmetallation with hydrides and reductive elimination afford aldehydes 441. Ketones 442 are produced by transmetallation with alkylmetal reagents and reductive elimination. 

This article presents a review of recent advances in the catalytic addition of alkylmetal reagents to olefins, excluding reactions that involve unsaturated carbonyl compounds as substrates (conjugate addition) [2]. As described below, these reactions provide efficient and selective routes to the synthesis of a wide variety of chiral, non-racemic organic molecules that can be used in the fabrication of a number of highly functionalized molecules. 

Diastereoselective and enantioselective addition of alkylmetal reagents to aldehydes, ketones, and imines has been reviewed. (g)... 

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