Direct Acyloxylation of C(sp2)-H and C(sp2)-X (X = Cl, Br) Bonds in Aromatic Amides Using Copper Bromide and 2-(4,5-Dihydro-oxazol-2-yl)-phenylamine.

Here we reported a method for Cu2+-catalyzed ortho-acyloxylation of either the C(sp2)-H or C(sp2)-X (X = Cl, Br) bond of aromatic amides with carboxylic acid, especially olefine acids, to obtain corresponding products in good yields up to 91%. The catalyst CuBr2 is cheap and stable to conserve in comparison with other metals, like Rh, Pd, Ru, and Cu+. This simple procedure is applicable for wide substrate scope and various functional groups to produce carboxylic esters without any additives or ligands.