Poly(4-vinylpyridinium bromide perbromide)1

[91650-35-0]  · (C7H8Br3N)n  · Poly(4-vinylpyridinium bromide perbromide)  · (MW )n(345.86)

(polymeric reagent used in the bromination of alkenes and ketones2)

Alternate Name: P(4-VPBPB).

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

Form Supplied in: orange solid granules with ~4 mequiv Br3-/g resin.

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

Bromination of Alkenes and Ketones.

Poly(4-vinylpyridinium bromide perbromide) can replace free Bromine in bromination of alkenes (eq 1) and ketones (eq 2).2 This reagent is stable in storage and is safer to use than liquid bromine. Product isolation is simplified since the polymer can be removed from the reaction mixture by filtration. After use, the reagent may be regenerated by addition of bromine or it can be converted to Poly(4-vinylpyridine) by treatment with aqueous Sodium Hydroxide.2 A variation of this reagent is the poly(4-vinylpyridine bromine complex) which brominates alkenes and alkynes3 and effects side chain allylic bromination of alkyl-substituted aromatic molecules.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.; Farrall, M. J.; Nuyens, L. J. J. Macromol. Sci., Chem. 1977, A11, 507.
3. Zabicky, J.; Mhasalkar, M.; Oren, I. Macromolecules 1990, 23, 3755.
4. Sket, B.; Zupan, M. JOC 1986, 51, 929.

William F. Wood

Humboldt State University, Arcata, CA, USA

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