Carbanion reactivity — σ-adduct formation and elimination in the reactions of the carbanion from bis(phenylsulfonyl)methane with 4-nitrobenzofurazan derivatives

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Date
2008-03
Authors
Crampton, M.R.
Isanbor, C.
Asghar, Basim H.M.
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Journal ISSN
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Publisher
NRC Canada
Abstract
1H NMR studies in [2H6]-DMSO show that the carbanion 4 from bis(phenylsulfonyl)methane reacts with 4,6-dinitrobenzofuroxan to yield a σ-adduct that undergoes base-catalysed elimination to yield an alkene derivative. Rate constants, measured spectrophotometrically, are reported for the corresponding reactions in methanol of 4 with 4-nitrobenzofurazan and some derivatives that give adducts at the 5-position. The intrinsic rate constant, ko, for this process has a value of 1.5 ± 0.5. The 5-adducts undergo methoxide-catalysed elimination of phenylsulfinic acid to yield alkene derivatives and rate constants for this process are reported.Key words: carbanions, 4-nitrobenzofurazan, σ-adducts, elimination reactions.
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Keywords
Research Subject Categories::NATURAL SCIENCES::Chemistry::Physical chemistry::Spectroscopy , carbanions , elimination reactions , 4-nitrobenzofurazan
Citation
Asghar, B. H., Crampton, M. R., & Isanbor, C. (2008). Carbanion reactivity—σ-adduct formation and elimination in the reactions of the carbanion from bis (phenylsulfonyl) methane with 4-nitrobenzofurazan derivatives. Canadian Journal of Chemistry, 86(3), 225-229.