Transformations of perfluorinated 1-alkyl-, 1-phenyl- and 1,2-dialkylbenzocyclobutenes under the action of SiO2/SbF5

• Published in: Journal of fluorine chemistry 2013-01, Vol.145, p.41-50
• Main Authors: Zonov, Yaroslav V., Karpov, Victor M., Platonov, Vyacheslav E., Rybalova, Tatjana V.
• Format: Article
• Language: English
• Subjects: Antimony pentafluoride; Benzocyclobutenes; Perfluorinated; Phthalanes; Phthalides; Silicon dioxide
• ISSN: 0022-1139; 1873-3328
• DOI: 10.1016/j.jfluchem.2012.11.004

[Display omitted] ► Rearrangements of perfluoroalkylbenzocyclobutenes in the reaction with SiO2/SbF5. ► Involvement of SiO2 in the four-membered ring cleavage. ► The influence of the substituent group on the reaction route. Heating of perfluorinated 1-methyl-, 1-ethyl- and 1-isopropylbenzocyclobutenes with SiO2 in an SbF5 medium at 75°C results in perfluoro-2-alkylbenzocyclobutenones or perfluoro-3-alkylphthalides formation. Perfluorinated 1,2-diethyl- and 1-ethyl-2-methylbenzocyclobutenes react with SiO2/SbF5 at 75°C to form, after treatment of the reaction mixture with water, perfluorinated 1,3-diethyl- and 1-ethyl-3-methylphthalan-1,3-diol, respectively. Perfluoro-1,2-diisopropylbenzocyclobutene under the action of SiO2/SbF5 at 95°C is converted to perfluoro-7,8-diisopropylbicyclo[4.2.0]octa-1,5,7-triene-3,4-dione and perfluoro-1,2-diisobutyrylbenzene. Perfluoro-1-methyl-2-phenylbenzocyclobutene does not react with SiO2 in an SbF5 medium at 75°C, perfluoro-1-phenylbenzocyclobutene in analogous conditions gives a mixture of perfluorinated 2-hydroxy-2-phenylbenzocyclobutenone and 2-benzoylbenzoic acid.