Charge Screening in the SN2 Reaction of Charged Electrophiles and Charged Nucleophiles: An Ionic Liquid Effect

The application of liquids that are salts at room temperature to chemical synthesis has become a hugely exciting field of study. The greatest promise that these ionic liquids hold is that they might offer process advantages, even novel behaviors that cannot be achieved in molecular solvents. We report here that the S(N)2 reaction of the trifluoromethanesulfonate and bis(trifluoromethanesulfonyl)imide salts of dimethyl-4-nitrophenylsulfonium ([p-NO2PhS(CH3)(2)](+)[X](-), [X](-) = [CF3SO3](-), [N(CF3SO2)(2)](-)) with chloride ion follow a fundamentally different pathway to when the same salts react in molecular solvents.