Various oxidative reactions with novel ion-supported (diacetoxyiodo)benzenes

Abstract

The oxidation of secondary alcohols and primary alcohols with two novel ion-supported (diacetoxyiodo)benzenes (IS-DIBs) A and B in the presence of a catalytic amount of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) in dichloromethane at room temperature proceeded efficiently to provide the corresponding ketones and aldehydes, respectively, in good yields. The oxidative reaction of N,N-diisopropylbenzylamines with those IS-DIBs was also carried out to generate the corresponding aromatic aldehydes in good yields. In addition, the Hofmann rearrangement of primary amides in methanol under basic conditions and the oxidative 1,2-rearrangement of propiophenones in trimethyl orthoformate under acidic conditions with those IS-DIBs provided the corresponding methyl carbamates and methyl 2-arylpropanoates, respectively, in good yields. Moreover, treatment of acetophenones with those IS-DIBs in the presence of trifluoromethanesulfonic acid in acetonitrile generated the corresponding 5-aryl-2-methyloxazoles in good yields. In those five reactions, the desired products were obtained in good yields with high purity by simple extraction of the reaction mixture with diethyl ether and subsequent removal of the solvent from the extract. Moreover, ion-supported iodobenzenes, which were the co-products derived from IS-DIBs in the present oxidative reactions, were recovered in good yields and could be re-oxidized to IS-DIBs A and B for reuse in the same oxidative reactions.