Decarboxylative Alkylcarboxylation of α,β-Unsaturated Acids Enabled by Copper-Catalyzed Oxidative Coupling

A facile and general
method for copper-catalyzed decarboxylative
alkylcarboxylation of cinnamic acids with dimethyl 2,2′-azobis­(2-methyl­propionate)
has been developed. The scope and versatility of the reaction was
demonstrated, and a broad range of substrates bearing electron-donating
and -withdrawing groups on the aromatic rings were all compatible
with this reaction to provide desired β,γ-unsaturated
esters in moderate to good yields. Moreover, α,β-unsaturated
acids with a carbonyl group on the γ-position of acrylic acids
also smoothly proceeded to furnish the desired products in good yields.