Product control of palladium-catalyzed aerobic oxidation of terminal olefins with electron- withdrawing groups can be achieved through modifying reaction conditions. When the oxidant, such as CuCl2/O2, benzoquinone/O2 or O2, was present in scCO2, aerobic oxidation of terminal olefins goes smoothly. With enough MeOH and sufficient oxygen, acetalization preponderated over cyclotrimerization, while with little MeOH as co-solvent ...