Focus on Physico-Chemical Properties of Sulfoximines: Acidity, Basicity and Lipophilicity.

Despite the numerous published syntheses and applications of sulfoximines, very few studies describe their physico-chemical properties and in particular their acidic, basic and lipophilic or hydrophilic characters. We report for the first time the acidity values (pK) of fluorinated sulfoximines in water and in acetonitrile, as well as the basicity (pK) measurements of fluorinated and non-fluorinated sulfoximines in acetonitrile. The same sulfoximine library was also studied in terms of lipophilicity with measurement of the Hansch parameters of the sulfoximine moieties. Finally, these new data allowed us to optimize the N-alkylation reaction of fluorinated sulfoximines.