Organocopper reagents enolates

Hydrolysis of the enol ethers obtained from the substitution reaction with the organocopper reagent yielded chiral b-substituted aldehydes with ees of 62 and 73% for the Sn2" and Sn2 products, respectively. 

Review Taylor has reviewed the conjugate addition-enolate trapping reactions of organocopper reagents, in particular of lithium dialkylcuprates (131 references). 

Conjugate additions of various organocopper reagents to the enones derived from glycals, e.g. 2-(diethoxyphosphoryl)hex-l-en-3-uloses, has been described. The reactions proved to be rapid, clean, and diastereoselective, giving rise to the formation of 3-oxo-2-phosphono-o -C-glycosides or the corresponding enol acetates.215... 

Similar to the addition reactions of acceptor-substituted dienes (Scheme 16), the outcome of the transformation depends on the regioselectivity of the nucleophilic attack of the organocopper reagent (1,4- vs. 1,6-addition) and of the electrophilic capture of the enolate formed. The allenyl enolate obtained by 1,6-addition can afford either a conjugated diene or an allene upon reaction with a soft electrophile, and thus opens up the possibility to create axial chirality. The first copper-mediated addition reactions to Michael acceptors of this type, for example, 3-alkynyl-2-cyclopentenone 75,... 

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