A variety of (substituted) aryl glyoxylates is formed in good to excellent yield under very mild conditions by direct oxidation of the corresponding arylacetic esters or mandelic acid esters with molecular oxygen and N-hydroxyphthalimide/cobalt (II) acetate as catalyst. Heteroaromatic analogs are more difficult to oxidize with this system. The effect of substitution in the aromatic ring of N-hydroxyphthalimide on the oxidation of ethylbenzene ...
