Oxidation of primary aliphatic and aromatic aldehydes with difluoro(aryl)-λ ³-bromane

Oxidation of primary aliphatic aldehydes with p- trifluoromethylphenyl(difluoro)-λ ³-bromane in dichloromethane at 0 °C afforded acid fluorides selectively in good yields, while that of aromatic aldehydes in chloroform at room temperature produced aryl difluoromethyl ethers. A larger migratory aptitude of aryl groups compared to primary alkyl groups during a 1,2-shift from carbon to an electron-deficient oxygen atom in bromane(III) Criegee-type intermediates will result in these differences in the reaction courses.