13C and 2H kinetic isotope effects and the mechanism of bromination of 1-pentene under synthetic conditions.

S R Merrigan, D A Singleton

Index: Org. Lett. 1(2) , 327-9, (1999)

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Abstract

[formula: see text] The 13C and 2H kinetic isotope effects for the bromination of 1-pentene with Br2 in CCl4 were determined and interpreted with the aid of calculationally predicted isotope effects. The isotope effects observed are consistent with rate-limiting bromonium ion formation and do not fit with either rate-limiting production of a pi complex or reaction of a reversibly formed bromonium ion. This rules out some of the mechanistic complexities suggested for other brominations, though the identity of the brominating reagent(s) under these synthetic conditions remains uncertain.