CATALYSIS AND SOLUTE EFFECTS IN THE SOLVOLYSIS OF 3 ARENESULFONYL CHLORIDES IN AQUEOUS TRIFLUOROETHANOL

Solvolyses in 1:1 (v/v) water-trifluoroethanol in the absence of Other solutes of 2-mesitylenesulfonyl chloride, 2, 2,4-dimethoxybenzenesulf onyl chloride, 3, and 4-bromobenzenesulfonyl chloride, 4, are solvent- induced S(N)2 reactions. Sodium trifluoroethoxide leads to an apprecia ble second-order term for all three substrates in accord with a direct S(N)2 reaction by the trifluoroethoxide anion. Sodium acetate and sod ium trimethylacetate also enhance the rates, principally by their effe ct upon the concentration of the conjugate base of the solvent. Effect s of other solutes are also reported.