Formation and substitution of remote ester-functionalized organocopper reagents

Article abstract of DOI:10.1021/om00040a028

Remote ester-functionalized aryl and alkyl organocopper compounds have been produced through the use of a highly reactive form of copper. Methyl 5-bromopentanoate and various alkyl halobenzoates undergo oxidative addition with active copper to produce methyl 5-cupriopentanoate and alkyl cupriobenzoates, respectively, in moderate to good yields. These organocopper reagents will cross-couple with acid chlorides to form the corresponding keto esters and with alkyl halides to produce the corresponding alkylated esters in moderate to good yields. The organocopper compounds could also be converted to their respective homocoupled dimers in varying yields by appropriate oxidative or thermal methods. Methyl 5-cupriopentanoate has a slight tendency to undergo an intramolecular cyclization to form, after aqueous workup, cyclopentanone and methanol.