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The Michael-type reaction of copper-catalyzed trialkylaluminium reagents with α,β-unsaturated carbonyl compounds is a useful and simple procedure for the transfer of hydrocarbon substituents. The scope of this process and the effect of chlorotrimethylsilane as additive were investigated. Preparatively useful results were generally obtained for enones even with higher organoaluminium reagents, whereas the reaction with α,β-unsaturated aldehydes was limited to the use of trimethylaluminium.

The effect of silanes as additives in the copper-catalyzed conjugate alkylation of enones by various organoaluminium reagents was investigated. TMSCl led to significant lower amounts of CuBr catalyst needed in the reaction of trimethylaluminium with enones, but was unsuccessful in the case of organoaluminium compounds of the formula Me 2 AlY (Y = Cl, OR). Me 2 AlOEt turned out to be a useful reagent for methylation without support of additives.

The effect of silanes as additives in the copper-catalyzed conjugate alkylation of enones by various organoaluminium reagents was investigated. TMSCl led to significant lower amounts of CuBr catalyst needed in the reaction of trimethylaluminium with enones, but was unsuccessful in the case of organoaluminium compounds of the formula Me 2 AlY (Y = Cl, OR). Me 2 AlOEt turned out to be a useful reagent for methylation without support of additives.