Visible-light induced decarboxylative coupling of phenoxyacetic acid with disulfides: synthesis of α-arylthioanisole derivatives

Photoredox-catalyzed cross-coupling reaction is an efficient strategy for the construction of organic molecules. Herein, we developed a method to synthesize α-arylthioanisoles by constructing C-S bonds in the presence of a Ru-photoredox catalyst. Thus, a series of α-arylthioanisole compounds were efficiently obtained through decarboxylative cross-coupling under mild conditions. This protocol features high efficiency, broad substrate scope and good functional group tolerance.

The Role of Dithiocarbamate Catalysts in the Diversification of Sulfur Speciation Towards Anionic Sulfur

Recently, there has been growing interest in the implementation of various "catalysts" to further diversify the substrate scope for inverse vulcanization reactions. While there have been several proposals on the mechanism of how these catalysts work, the speciation of sulfur in these mixtures has remained elusive. As a key component to understanding when and if these catalysts are appropriate, we sought to elucidate the role of dithiocarbamate species in inverse vulcanization reactions by attempting to characterize the speciation of sulfur. The reaction efficacy for various substrates containing different functional groups with sulfur, either with or without a metal dithiocarbamate, potassium diethyldithiocarbamate (K-DTC), suggests the formation of a rapidly fluctuating sulfur speciation and, most importantly, the presence of anionic sulfur. The work concludes with some suggestions on best practices for the utilization of dithiocarbamate catalysts based on our results.

Base-mediated synthesis of cyclic dithiocarbamates from 1-amino-3-chloropropan-2-ol derivatives and carbon disulfide

An efficient method for the preparation of six-membered cyclic dithiocarbamates is described, in which triethylamine effectively promotes the reaction of 1-amino-3-chloropropan-2-ol derivatives with carbon disulfide. On the basis of the experimental and theoretical studies, a reaction mechanism is proposed to explain the difference between the present reaction and our previously reported carbon dioxide fixation.

Transition metal-free coupling reactions of benzylic trimethylammonium salts with di(hetero)aryl disulfides and diselenides

A new protocol was developed to synthesize (enantioenriched) thioethers and selenoethers from (chiral) benzylic trimethylammonium salts and di(hetero)aryl disulfides or diselenides. These syntheses were promoted by the presence of weak base and did not require the use of any transition metal, and resulted in the target products with good to excellent yields (72-94%). Using quaternary ammonium salts synthesized from enantiomerically enriched amines led to highly enantiopure benzylic thioethers and selenoethers (94-99% ee) with configurations reversed from those of their enantioenriched quaternary ammonium salts.