Sulfonates as Versatile Structural Counterions of Epoxidized Salts

Organothianthrenium salts: synthesis and utilization

Organothianthrenium salts are a class of compounds containing a positively charged sulfur atom and a neutral sulfur atom. Over the past years, organothianthrenium salts have been emerging as attractive precursors for a myriad of transformations to forge new C-C and C-X bonds due to their unique structural characteristics and chemical behaviors. The use of the thianthrenation strategy selectively transforms C-H, C-O, and other chemical bonds into organothianthrenium salts in a predictable manner, providing a straightforward alternative for regioselective functionalizations for arenes, alkenes, alkanes, alcohols, amines and so on through diverse reaction mechanisms under mild conditions. In this review, the preparation of different organothianthrenium salts is summarized, including aryl, alkenyl and alkyl thianthrenium salts. Moreover, the utilization of organothianthrenium salts in different catalytic processes and their synthetic potentials are also discussed.

2-Hydroxy-3-(1-(4-vinylbenzyl)imidazol-3-ium-3-yl)propane-1-sulfonate and 3-(4-Vinylbenzyl)dimethylammonio)-2-hydroxypropane-1-sulfonate as New Zwitterionic Monomers

Zwitterionic polymers emerge as very useful materials for applications in antifouling surfaces. The properties of these polymers can be tuned by variations of the chemical structure of the corresponding monomer. In this study, two zwitterionic ammonium sulfonate monomers, bearing hydroxyl function and styrenic polymerizable groups, were prepared in two steps. The two monomers were obtained using 4-vinylbenzyl chloride as the key precursor. The zwitterionic monomers were characterized by 1H NMR, 13C NMR, IR spectroscopy, and high-resolution mass spectrometry (HRMS). These two monomers enable the preparation of novel zwitterionic polymers with enhanced hydrophilicity, due to the presence of a hydroxyl group.

Synthesis of 1-[1H,1H,2H,2H-perfluooctyl]-3-[2-(oxiran-2-yl)ethyl]imidazolium 4-[(2-oxiran-2-yl)ethoxy]benzenesulfonate as a New Perfluorinated Ionic Monomer

Access to perfluorinated compounds represents a growing challenge in the academic and industrial fields to achieve target compounds with specific physico-chemical properties. Especially, the insertion of a perfluorinated chain within an ionic liquid can provide improvements not just in terms of hydrophobicity and lipophobicity, but also viscosity, density as well as thermal stability. In this research area, we have recently developed new access points to several epoxy imidazolium salts combined with fluorinated anions such as bistriflimide (NTf2−), hexafluorophosphate (PF6−) or tetrafluoroborate (BF4−). Here, we reported the synthesis of a perfluorinated imidazolium cation associated with a sulfonate anion as a new functionalized partner. This sequence required four steps from imidazole (cationic part) and three steps from sodium 4-hydroxybenzenesulfonate (anionic part), respectively. This perfluorinated ionic liquid was fully characterized by nuclear magnetic resonance with 1H-NMR, 19F-NMR, 13C-NMR, DEPT, COSY, HSQC, HMBC and IR spectroscopy. The two parts of the salt were confirmed by high-resolution mass spectrometry (HRMS), and we combined thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) to determine the thermal properties of this new compound.