𝔖 Bobbio Scriptorium
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Concerted chain isomerization in protonated alkylbenzenes

✍ Scribed by J. P. Denhez; H. E. Audier; D. Berthomieu

Book ID
102560281
Publisher
John Wiley and Sons
Year
1993
Tongue
English
Weight
253 KB
Volume
28
Category
Article
ISSN
1076-5174

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✦ Synopsis

Abstract

The first step in the unimolecular reaction of metastable protonated alkylbenzenes is the stretching of the C(benzene)—C(α) bond. Therefore, the intermediacy of a π‐complex [C~6~H~6~, alkyl^+^] has often been proposed. In this work, the kinetic energy releases associated with the [tert‐alkyl]^+^ product were measured for a large number of [C~6~H~6~–C__n__H] (n > 3) ions. At least for β‐branched alkylbenzenes, it is shown that the chain isomerization which occurs prior to dissociation involves neither the [C~6~H~6~, C__n__H] π‐complex nor a [C~6~H~7~^+^, alkene] ion–neutral complex. The data are explained by a concerted process in which the stretching of the C(benzene)—C(α) bond is accompanied by the migration of the tertiary β‐hydrogen from C(β) to C(α).

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