Emerging Organosulfonium Electrophiles as Unique Reagents for Carbon–Sulfur Bond Formation: Prospects in Synthetic Chemistry of Organosulfur Compounds

Abstract

Carbonsulfur (CS) bond formation is one of the important synthetic routes in organic chemistry. Among sulfur sources for CS bond formation, organosulfur cations (RS + ) and their synthetic equivalents are unique reagents. These cationic sulfur species are easily prepared as compared with the oxonium analogues, because of their low ionization potentials. This review describes various synthetic methods for CS bond formation, mainly focusing on electrophilic reactions, addition to olefins, and substitution to aromatic rings. A breakthrough has been anticipated for RS + electrophiles, based on their versatile utility in aromatic polymer synthesis.

Mechanistic and Synthetic Investigations on the Dual Selenium-π-Acid/Photoredox Catalysis in the Context of the Aerobic Dehydrogenative Lactonization of Alkenoic Acids

“…30 In conclusion, the results of these ESI-MS experiments suggest that (a) diselanes are most likely regenerated under oxidative conditions from intermediates of type 4, potentially through the mechanism illustrated in Scheme 2 (scenario b), and (b) triselenonium species (ArSe) 3 + and related polyselenonium cations may likely be operative intermediates in the catalytic cycle. It is important to point out that, in contrast to sporadic reports on olefin functionalizations mediated by trisulfonium cations [(ArS) 3 ] + , 28,31 cognate triselenonium cations have so far not been generally considered as catalytically active intermediates in analogous SET oxidation processes on the basis of experimental results but rather the corresponding monomeric selenenium electrophiles (RSeY). 9a,42 To validate the hypothesis that triselenonium cations may lead to the very same intermediates and products that were observed under photocatalytic conditions (i.e., intermediates 4 and products 2; cf.…”

Regioselective C–H Sulfanylation of Aryl Sulfoxides by Means of Pummerer-Type Activation

“…However, these halogen-based strategies often suffer from narrow substrate scope or heavy metal contaminations of products. To avoid such problems, significant efforts have been devoted to invent C–H sulfanylation of arenes under metal-free conditions. , However, previous methods entirely focused on Friedel–Crafts-type reactions of arenes with electrophilic sulfur reagents or their precursors, i.e., N -sulfanylsuccinimides, disulfides, thiols, and so on . Consequently, harsh reaction conditions and/or highly electron-rich arenes such as anilines, phenols, and indoles have been required (Scheme A).…”

Synthesis of colorless and high-refractive-index sulfoxide-containing polymers by the oxidation of poly(phenylene sulfide) derivatives

“…Poly(2,6-dimethyl-1,4phenylenesulfide) (PMPS) and poly(2-methoxy-1,4-phenylenesulfide) (OMePPS) were prepared according to a previous report. 12,15 Measurements 1 H and 13 C NMR spectra were obtained using a JEOL ECX500 spectrometer (500 Hz), and the samples for NMR experiments were prepared by adding tetramethylsilane (TMS) as an internal standard. The molecular weights of polymers were determined using a SHIMADZU CBM-20A and SPD-20MA, with a TOSOH TSKgel SuperHM-N column (eluent: chloroform or DMF (containing 0.1 M LiCl), flow rate: 0.3 mL min −1 ).…”

“…Our group found that poly(phenylene sulfide) (PPS), regarded as one of the super engineering plastics with high crystallinity and thermal stability, became completely amorphous once it was derivatized with alkyl or alkoxyl side groups. [11][12][13][14][15][16][17] These PPS derivatives presented not only good solubility in organic solvents, but also high transparency and high RI, all of which were suitable for optical applications.…”