α-Oxidation of Ketones Catalyzed by IL-Supported Aryl Iodides

Significance

Ionic liquid (IL)-supported aryl iodides A-D were designed and prepared with a view to use them as recyclable catalysts for α-tosyloxylation of ketones. The reaction was carried out in an ionic liquid, ethylmethylimidazolium tosylate ([emim]OTs), in the presence of 10 mol% of the IL-supported aryl iodide, MCPBA, and p-toluenesulfonic acid to give the corresponding α-tosyl­oxylated ketones. Representative results are shown above. After the reaction, the IL-based reaction mixture was extracted with ethyl acetate, and the extract (containing α-tosyloxy ketone and co-produced MCPBA) was washed with sat. NaHCO₃ to give the desired α-tosyloxy ketone. The resulting IL phase was then subjected to the next series of the reaction under similar conditions to exhibit good recyclability.