Organocopper compounds, reactions with acyl halides

FIGURE 15.48 Preparation of organocopper compounds and their reaction with acyl halides. 

While a large number of studies have been reported for conjugate addition and Sn2 alkylation reactions, the mechanisms of many important organocopper-promoted reactions have not been discussed. These include substitution on sp carbons, acylation with acyl halides [168], additions to carbonyl compounds, oxidative couplings [169], nucleophilic opening of electrophilic cyclopropanes [170], and the Kocienski reaction [171]. The chemistry of organocopper(II) species has rarely been studied experimentally [172-174], nor theoretically, save for some trapping experiments on the reaction of alkyl radicals with Cu(I) species in aqueous solution [175]. 

Organocopper compounds, RCu, though less reactive toward acid halides, couple to give the corresponding ketones as well. Reaction of alkynylcoppers with acyl halides produces acetylenic ketones in good yields (Normant and Bourgain, 1970). 

FIGURE 15.49 Mechanism of reaction of organocopper compounds with acyl halides. 

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