Palladium( II )-catalysed oxidation of carbon–carbon double bonds of allylic compounds with molecular oxygen; regioselective formation of aldehydes

Treatment of N-allylamides 1a–c and lactams 1d–f with molecular oxygen in the presence of [PdCl2(MeCN)2]–CuCl catalyst in anhydrous 1,2-dichloroethane containing hexamethylphosphoric triamide gives the corresponding aldehydes 2 regioselectively, while methyl ketones 3 become the major products in the presence of water.