Electrophilicity of perfluoroisobutylene and methyl perfluoromethacrylate

Autor: E. I. Mysov, E. M. Rokhlin, E. P. Lur'e, N. P. Gambaryan, E. G. Gal'pern
Rok vydání: 1980
Předmět:
Zdroj: Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. 29:437-442
ISSN: 1573-9171
0568-5230
DOI: 10.1007/bf00949630
Popis: 1. Interaction of m- and p-fluorophenylmagnesium bromide with perfluoroisobutylene or with methyl perfluoromethacrylate gives the corresponding arylperfluoroisobutylenes and methylα-trifluoromethyl-β-fluoro-β-arylacrylates. 2. Examination of the19F NMR spectra of substituted m- and p-fluorobenzenes reveals that the unsaturated units CF=C(CF3)X and trans-CH=CHX have a greater deshielding effect on the fluorine nucleus in C6H4F when X=CF3 than when X=CO2Me. 3. Extended Huckel and CNDO/2 calculations on methyl perfluoromethacrylate and perfluoroisobutylene reveal that the negative π-electron charge on the “central” carbon atom is more efficiently delocalized by the methoxycarbonyl group than the trifluoromethyl. 4. The higher electrophilicity of methyl perfluoromethacrylate relative to perfluoroisobutylene stems from the greater ability of the alkoxycarbonyl group to stabilize the intermediate carbanion or the carbanion-like transition state in the reaction with the nucleophile.
Databáze: OpenAIRE
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