Elimination reactions on the borderline between concerted and stepwise processes. Base-promoted dehydrohalogenation of 2-phenylsulphonylethyl bromide, chloride, and fluoride
Fiandanese, Vito; Marchese, Giuseppe; Naso, Francesco
Журнал:
Journal of the Chemical Society, Perkin Transactions 2
Дата:
1973
Аннотация:
The reactions of 2-phenylsulphonylethyl bromide, chloride, and fluoride with methoxide ion in methanol and with triethylamine in acetonitrile and in benzene, have been followed kinetically. The reactivity order Br > Cl > F has been observed. The kinetic isotope effects were determined for the nine substrateâ baseâ solvent combinations. The measured k H/k D values range from a maximum of 5·0 in the case of the bromo-derivative in alcohol to a minimum of 1·0 in the case of the fluoro-derivative in benzene. On the basis of isotope effects, leaving group effects, and related observations the position of the elimination mechanism in the E2â E1 cB spectrum is tentatively located.
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