Alkylsulfonioarylene and Thioarylene Polymers Derived from Sulfonium Electrophiles

Abstract

Superacidification of sulfoxides and sulfinates effects the electrophilic substitution reaction of the resulting hydroxysulfonium ions onto aromatic rings with the elimination of H2O at room temperature. The present account emphasizes the utility of the reaction for use as an elementary step in organic synthesis. The product, the alkyldiarylsulfonium ion, often quantitatively obtained, allows the synthesis of alkylsulfonio-bridged (λ4-alkylsulfanyliumdiyl) aromatic polymers. High molecular-weight poly(alkylsulfonioarylene) salts with a wide range of structural dimensionalities from linear to network architectures have been made accessible by the regioselective condensation of aryl sulfoxides. The polymers possess interesting properties such as good solubility in polar organic solvents and sometimes even in H2O, susceptibility to nucleophiles to provide thioarylene derivatives, photo-degradability, and electric semiconductivity, according to the dimensionality of the molecule. The synthetic chemistry of the alkylsulfonioarylene polymers as well as their possible applications in high molecular-weight poly(thioarylene) synthesis, photochemical recycling processes of an engineering plastic poly(thio-1,4-phenylene), and photo-resist technologies, are reviewed.

Electro- and Magneto-Responsible Chiral Polymers

“…(33 in this chapter. The key step to form the ladder structure comprised of a fused phenoxathiine ring was the one-pot quantitative ring-closing reaction of the pendant alkyl sulfoxide group on the aromatic polymer, which has been already reported by the authors' group [104,105]. In addition, a crucial factor to synthesize the helical molecules is how to control the helicity.…”

“…The pendant alkyl sulfide of 51 was quantitatively oxidized using peracetic acid to afford the alkyl sulfoxide derivative 50. The intramolecular ring-closing condensation with excess pure triflic acid or the electrophilic attack of the pendant sulfoxide on the 4 or 6 position of the adjacent phenylene unit slowly proceeded in comparison with the previous ladder polymers which were prepared by the authors' group [105,114,115]. After one week, the ringclosure produced a ladder polymer 49 in which the tetrahydro-thiophenium bridge between the benzene rings was formed without any structural defects based on the NMR spectroscopy.…”

Synthesis and characterization of a π‐conjugated hybrid of oligothiophene and porphyrin

“…π‐Conjugated porphyrin polymers have been employed in sensors,2–5 (electro)optical devices,6–8 and solar energy conversion systems 9–11. Coupling porphyrins as pendant groups to π‐conjugated backbones12–21 often result in physical distortions or changes in electronic density and thereby alters the properties of the backbone. Indeed, most of polythiophene derivatives containing porphyrin substituents are insulators with electrical conductivities of less than 10 −8 S/cm 22.…”

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

“…The V=O complex has to be activated with a strong acid to form the active form of the catalyst, [V-O-V] 2+ . 45 The catalyst allowed 4-electron reduction of O 2 to H 2 O without producing the partially reduced active oxygen species, which contributed to enhance the selectivity of the reaction. The catalytic mechanism is illustrated in Scheme 17.…”