Reaction of tert-alkoxyl and alkyl radicals with styrene studied by the nitroxide radical-trapping technique

Tomoyuki Nakamura, W. Ken Busfield, Ian D. Jenkins, Ezio Rizzardo, San H. Thang, Shuji Suyama

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28 Citations (Scopus)

Abstract

The reactions of tert-alkyl peroxypivalates 1 (R = methyl, ethyl, and n- propyl) with styrene in the presence of the free-radical scavenger (1,1,3,3- tetramethyl-2,3-dihydro-1H-isoindol-2-yl)oxyl (2) have been studied at 60 °C. tert-Butyl and tert-alkoxyl radicals (tert-butoxyl, tert-pentyloxyl, and tert-hexyloxyl radicals) were generated from the thermolysis of 1, and the derivative alkyl radicals (methyl, ethyl, n-propyl, and 4-hydroxy-4- methylpentyl radicals) were formed by subsequent unimolecular reactions (β- scission and 1,5-H shift) of the corresponding tert-alkoxyl radicals. The extent of the unimolecular reactions of the tert-alkoxyl radicals (versus addition to styrene) and the relative reactivity of alkyl radicals toward addition to styrene were obtained from the competitive addition/trapping reactions. The absolute rate constants for the addition of tert-butyl, ethyl, methyl, and n-propyl radicals to styrene at 60 °C were estimated to be (7.4, 4.7, 5, and 5.4) x 105 M-1 s-1, respectively.

Original languageEnglish
Pages (from-to)5578-5582
Number of pages5
JournalThe Journal of Organic Chemistry
Volume62
Issue number16
DOIs
Publication statusPublished - 1 Jan 1997

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