Benzothiazole-Derived Sulfones and Sulfoxides as Reactive Templates for Biothiols and Sulfane Sulfurs

Abstract

In this work we studied the reactions of benzothiazole sulfones and sulfoxides toward reactive sulfur species. The reaction of thiols with benzothiazole sulfones produces sulfinic acids (RSO2H), which can further react with sulfane sulfurs to form thiosulfonic acids (RSO2SH). This was used to design fluorescent sensors for hydrogen polysulfides. The reaction of thiols with benzothiazole sulfoxides produces sulfenic acids (RSOH), which can undergo fast intramolecular cyclization and be used to design thiol-triggered fluorescent sensors.

Catalytic Asymmetric α‐Alkylsulfenylation with a Disulfide Reagent

“…However, synthetic potentials of disulfides as alkyl sulfenylation reagents have not been explored in asymmetric catalysis. Recently, Xian reported a thioazole‐containing disulfide for the ligation of proteins [9, 11] . Inspired by this work, we herein reported a new type of alkyl sulfenylation reagents based on disulfides derived from 2‐mercapto‐5‐methyl‐1,3,4‐thiadiazole (MMTD) (Scheme 1, B).…”

“…Recently, Xian reported a thioazole-containing disulfide for the ligation of proteins. [9,11] Inspired by this work, we herein reported a new type of alkyl sulfenylation reagents based on disulfides derived from 2-mercapto-5-methyl-1,3,4-thiadiazole (MMTD) (Scheme 1, B). MMTDsulfides can be successfully applied in the asymmetric alkyl sulfenylation reaction by chiral primary aminocatalysis.…”

Synthesis and Application of Two-Photon Active Fluorescent Rhodol Dyes for Antibody Conjugation and In Vitro Cell Imaging

“…43 At first, an activated 44 NHS ester of 11d was prepared with TSTU (18), followed by the smooth acylation of 3azidopropane-1-amine (19), resulting in 17. Then, we were able to label the antibody (12) with the fluorescent dye in a copper-free strain-promoted azide-alkyne click reaction at room temperature. The antibody−fluorophore conjugate 13 was characterized by UV/Vis spectroscopy to determine the fluorophore−antibody ratio (FAR).…”

“…However, there was still some room for improvement in fluorescence properties, and therefore, on the one hand, an electron-donating julolidine core − was incorporated into next-generation compounds ( 3 ) that inhibits the internal rotation of the amino group, decreasing the twisted intramolecular charge transfer (TICT). On the other hand, in some cases, the π-system was extended ( 4 ) to fine-tune the emission. − Furthermore, rhodols were also used as fluorescent probes for inorganic (H 2 O 2 and HOCl) ( 5 and 6 ) or glutathione-detecting probes ( 7 ). The latter compound ( 7 ) was also applied in biological systems (Figure B). − …”