Poly[4-(diacetoxyiodo)styrene]

(C12H13IO4)n (MW 348.12) (polystyrene-supported derivative of (diacetoxyiodo)benzene used in the oxidation of aniline,1, 2 oxidation of hydroquinones,3-5 oxidative spirocyclization,4 phenolic oxidative coupling,6, 7 oxidation of alcohols,4, 8 oxidative cleavage of diols,1 α-hydroxylation and α-acetoxylation of ketones,3-5 oxidative 1,2-aryl migrations of alkyl aryl ketones,3, 9 generation of carbonyls from hydrazones and oximes,5 oxidation of sulfides3, 5 and thiols,5 iodination of aromatic rings,3, 9 preparation of heterocycles,10, 11 preparation of diaryliodonium salts,12, 13 and the oxidation of triphenylphosphine,5 organotellurium compounds5 and organoselenides14) Alternate Name: PS-I(OAc)2, poly[styrene(iodosoacetate)], polymer-supported (diacetoxyiodo)benzene, PSDIB, polymer-supported phenyliodine diacetate, poly-p-iodosostyryldiacetate. Physical Data: loading ca. 2.0–3.5 mmol g−1.4, 5, 10, 11 Solubility: some solubility in organic solvents such as CH2Cl2 (DCM), EtOAc, and CHCl3; insoluble in Et2O and MeOH. Analysis of Reagent Purity: iodometry and elemental analysis.3-5, 9-11 Preparative Methods: a solution of polystyrene (32 g, 0.31 mol), diiodine (32 g, 0.25 mol), iodine pentoxide (12 g, 0.04 mol), carbon tetrachloride (40 mL) and 50% sulfuric acid (60 mL) in nitrobenzene (400 mL) was kept at 90 °C for 39 h. The reaction mixture was cooled, diluted with chloroform (200 mL) and precipitated with methanol. Filtration gave poly(4-iodostyrene) (65 g) as a pale yellow powder. A mixture of poly(4-iodostyrene) (5 g) and peracetic acid solution [prepared from 30% hydrogen peroxide (25 mL) and acetic anhydride (90 mL)] was kept at 30–40 °C overnight. Precipitation with diethyl ether and filtration gave poly[4-(diacetoxyiodo)styrene] (5.7 g) as a white powder.1, 12 The loading is determined by iodometry or elemental analysis.3-5, 9-11 Handling, Storage, and Precautions: resin is best stored protected from direct sunlight and in a refrigerator, although no appreciable decomposition was observed at room temperature.4, 10