Alkyl copper

M-C(t bonds can be formed by each of the metals. The simple alkyls and ai7ls of Ag are less stable than those of Cu while those of Au have not been isolated. Copper alkyls and ai7ls are prepared by the action of LiR or a Grignard reagent on a Cu halide ... 

Results from the same laboratory have appeared on carbon dioxide complexes with copper(I) compounds (124). Phosphine-containing copper(I) car-boxylate complexes, formed by the insertion of C02 into a copper-alkyl bond, take up additional C02. A complex, formulated as [(RC00)Cu(C02)-(PPh3)J has been isolated and the C02 shown to be labile, i.e., the C02 was lost on attempted recrystallization. The authors speculate that the car-... 

Carbon monoxide insertion into the copper-alkyl bond is indirectly shown by reaction of CO with dibutylcuprate(I), an anionic dialkyl derivative of dicoordinated copper(I). The product of the reaction, dibutylketone, may be rationalized by assuming carbon monoxide coordination to the anionic copper complex, followed by alkyl migration to the unstable anionic complex Cu[C(0)Bu](Bu) , with subsequent reductive elimination to the observed organic product. 

The yields in this type of synthesis are generally better than 90% (based on dissolved anode material) and the isolated material is of high purity (55). Anionic species [Cu(SR) ] " with n > 1 are generally not isolated and both copper alkyl- and arenethiolates are accessible in this way. Moreover, this technique also allows access to copper selenolates [Cu(SeR)] (57). 

Sadighi and coworkers were the first to report the reactivity of NHC-copper boryl complexes for the reduction of CO2 to CO [39]. Later, DFT studies imder-taken by Marder and coworkers showed that the reduction occmred through CO2 insertion into the Cu—B bond to give Cu-C02-boryl species [40]. Subsequent boryl migration from C to O allowed the release of CO. Importantly, CO2 insertion also occurred in NHC-copper alkyl systems. However, the energy barrier does not favor the migration and the CO elimination. 

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