| Abstract
| - We report a quantitative comparison of the rates of nucleophilic reactions in ionic liquids and molecularsolvents taking place at a cationic center. Cationic sulfonium electrophiles were reacted with three aminenucleophiles (n-butylamine, di-n-butylamine, and tri-n-butylamine) in several molecular solvents (toluene,dichloromethane, tetrahydrofuran, acetonitrile, and methanol) and ionic liquids {1-butyl-1-methylpyrrolidiniumbis(trifluoromethanesulfonyl)imide, 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and 1-butyl-3-methylimidazolium trifluoromethanesulfonate}. The solvent effects on these reactions are examined using a linear solvation energy relationshipbased on the Kamlet−Taft solvent scales (α, β, and π*). These correlations reveal that hydrogen-bondinginteractions provide the dominant effects in determining the rate of reaction. In particular, hydrogen bondsdonated by the sulfonium electrophile to the solvent are the most important controlling factor on the rate ofnucleophilic reaction.
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