Poly(4-vinylpyridinium dichromate)1

[82246-45-5]  · (C14H16Cr2N2O7)n  · Poly(4-vinylpyridinium dichromate)  · (MW )n(428.32)

(polymeric oxidizing agent used to convert alcohols to aldehydes and ketones2)

Alternate Name: P(4-VPDC).

Physical Data: mp >300 °C.

Solubility: insol all solvents; polymer swells when added to aqueous and nonaqueous solvents.

Form Supplied in: brown powder.

Handling, Storage, and Precautions: store in a tightly closed container in a cool dry place.

Oxidation of Alcohols to Aldehydes and Ketones.

Poly(4-vinylpyridinium dichromate) is a solid polymeric reagent that readily oxidizes primary and secondary alcohols to aldehydes and ketones (eq 1).2,3 The reagent works best when it is soaked in water, filtered, and used in a nonpolar solvent such as cyclohexane. All chromium ions in oxidized or reduced form are retained on the polymer. Product isolation is simplified since the polymer is removed from the reaction mixture by filtration. This reagent may be regenerated.2,3 A variation of this polymeric reagent is a silver dichromate-poly(4-vinylpyridine) complex that rapidly converts alcohols to the corresponding aldehyde or ketone.4

1. (a) Goe, G. L.; Marston, C. R.; Scriven, E. F. V.; Sowers, E. E. In Catalysis of Organic Reactions; Blackburn, D. W., Ed.; Dekker: New York, 1990; pp 275-286. (b) Fréchet, J. M. J.; de Meftahi, M. V. Br. Polym. J. 1984, 16, 193.
2. Fréchet, J. M. J.; Darling, P.; Farrall, M. J. Polym. Prepr., Am. Chem. Soc. Div. Polym. Chem. 1980, 21, 272.
3. Fréchet, J. M. J.; Darling, P.; Farrall, M. J. JOC 1981, 46, 1728.
4. Tamami, B.; Hatam, M.; Mohadjer, D. Polym. Bull. (Berlin) 1989, 21, 531.

William F. Wood

Humboldt State University, Arcata, CA, USA

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