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Isolation of an Antiaromatic 9-Hydroxy Fluorenyl Cation.

ABSTRACT: Fluorenyl cations are textbook examples of 4π electron antiaromatic five-membered ring systems. So far, they were reported only as short-lived intermediates generated under superacidic conditions or by flash photolysis. Attempts to prepare a m-terphenyl acylium cation by fluoride abstraction from a benzoyl fluoride gave rise to an isolable 9-hydroxy fluorenyl cation that formed by an intramolecular electrophilic attack at a flanking mesityl group prior to a 1,2-methyl shift and proton transfer to oxygen.

SUBMITTER: Duvinage D

PROVIDER: S-EPMC8252458 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature

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Isolation of an Antiaromatic 9-Hydroxy Fluorenyl Cation.

Duvinage Daniel D Mebs Stefan S Beckmann Jens J

Chemistry (Weinheim an der Bergstrasse, Germany) 20210506 31

Fluorenyl cations are textbook examples of 4π electron antiaromatic five-membered ring systems. So far, they were reported only as short-lived intermediates generated under superacidic conditions or by flash photolysis. Attempts to prepare a m-terphenyl acylium cation by fluoride abstraction from a benzoyl fluoride gave rise to an isolable 9-hydroxy fluorenyl cation that formed by an intramolecular electrophilic attack at a flanking mesityl group prior to a 1,2-methyl shift and proton transfer t ...[more]

PMID: 33835609

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