Umpolung Reactivity of Fluoroalkylselenotoluenesulfonates: Towards a Versatile Reagent

Direct trifluoromethylselenolations of electron-rich (hetero)aromatic rings with N-trifluoromethylselenolating saccharin

A novel, easily synthesizable, shelf-stable electrophilic trifluoromethylselenolating reagent, N-trifluoromethylselenosaccharin, has been developed. This reagent can be synthesized in good yield by a two-step one-pot reaction from BnSeCF3, SO2Cl2, and silver saccharin. N-Trifluoromethylselenosaccharin proves to be an efficient trifluoromethylselenolating reagent, enabling the direct trifluoromethylselenolation of various electron-rich aromatic and heteroaromatic rings under mild reaction conditions. It exhibits excellent chemoselectivity and excellent compatibility with various functional groups, making it suitable for late-stage trifluoromethylselenolation applications in complex natural product and drug synthesis.

Visible-light-promoted trifluoromethylselenolation of ortho-hydroxyarylenaminones

Development of an efficient process that employs easy to handle and shelf-stable reagents for the synthesis of trifluoromethylselenylated heterocyclics remains a daunting challenge in organic synthesis. Herein, we report a...

Chemical reduction of Ag+ to Ag employing organic electron donors: evaluation of the effect of Ag+-mediated cytosine-cytosine base pairing on the aggregation of Ag nanoparticles

Ag⁺-mediated base pairing is valuable for synthesising DNA-based silver nanoparticles (AgNPs) and nanoclusters (AgNCs). Recently, we reported the formation of a [Ag(cytidine)₂]⁺ complex in dimethyl sulfoxide (DMSO), which facilitated the evaluation of the effect of cytosine-Ag⁺-cytosine (C-Ag⁺-C) base pairing on the degree of AgNP aggregation in solution. As an aprotic solvent, DMSO was expected to dissolve the [Ag(cytidine)₂]⁺ complex, and powerful reducing agents, such as organic electron donors. In this study, the chemical reduction of a cytidine/Ag⁺ system using a powerful reducing agent tetrakis(dimethylamino)ethylene (TDAE) was investigated. ¹H/¹³C/¹⁵N NMR spectroscopic evidence was obtained to identify the iminium dication (TDAE²⁺), which is an oxidised form of TDAE. The results were compared with those obtained using another organic electron donor, tetrathiafulvalene (TTF), which exhibits a relatively lower reduction activity than TDAE. AgNPs prepared via redox reaction between [Ag(cytidine)₂]⁺ and organic electron donors (TDAE and TTF) were characterised using UV-Vis spectroscopy and nanoparticle tracking analysis. It was found that the formation of C-Ag⁺-C base pairing inhibited the aggregation of AgNPs in solution. In addition, in the presence of cytidine, the total concentration of the AgNP solution was affected by the reduction activity of the reducing agent.

Metal-free nucleophilic trifluoromethylselenolation via an iodide-mediated umpolung reactivity of trifluoromethylselenotoluenesulfonate

We report herein a practical method to generate CF₃Se^- (and R_FSe^-) anions from shelf-stable reagents under iodide activation. Metal-free nucleophilic trifluoromethylselenolations have been then performed with this in situ-generated anion. Perfluoroalkylselenolations have also been described.

Metal-free oxidative trifluoromethylselenolation of electron-rich (hetero)arenes with the readily available [Me4N][SeCF3] reagent

The first oxidative trifluoromethylselenolation of nucleophilic (hetero)arenes with the nucleophilic [Me₄N][SeCF₃] salt under transition-metal-free conditions is described.