Copper-catalyzed ring-opening trifluoromethylthiolation/trifluoromethylselenolation of cyclopropanols with TsSCF3 or Se-(trifluoromethyl) 4-methoxybenzenesulfonoselenoate

We report a ring-opening trifluoromethylthiolation of cyclopropanols with TsSCF₃ by using Cu(OAc)₂ as the catalyst. Moreover, by using this strategy, the trifluoromethylselenolation of cyclopropanols with Se-(trifluoromethyl) 4-methoxybenzenesulfonoselenoate to access β-SeCF₃-substituted carbonyl compounds is achieved for the first time. The broad substrate scope, readily accessible reagents and cheap catalyst make this protocol an alternative and efficient method for the synthesis of β-SCF₃-substituted or β-SeCF₃-substituted carbonyl compounds.

Visible-Light-Induced Radical gem-Iodoallylation of 2,2,2-Trifluorodiazoethane

A visible-light-induced radical gem-iodoallylation of CF₃CHN₂ was developed under mild conditions, delivering a variety of α-CF₃-substituted homoallylic iodide compounds in moderate to excellent yields. The transformation features broad substrate scope, good functional group compatibility, and operational simplicity. The described protocol provides a convenient and attractive tool to apply CF₃CHN₂ as CF₃-introduction reagent in radical synthetic chemistry.

Visible-Light-Promoted Trifluoromethylthiolation and Trifluoromethylselenolation of 1,4-Dihydropyridines

We report a metal-free trifluoromethylthiolation and trifluoromethylselenolation of 1,4-dihydropyridines with S-(trifluoromethyl) 4-methylbenzenesulfonothioate and Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate under visible light irradiation. This transformation was tolerated with a wide range of functional groups and provided an alternative and green strategy for the synthesis of trifluoromethylthioesters and trifluoromethylselenoesters.

A density functional theory study on the mechanism of simultaneous trifluoromethylation and oximation of aryl-substituted ethylenes

The effects of different substituents, located at the para position of the aromatic ring and at the β-carbon atom of styrenes, on difunctionalizations involving trifluoromethylation and oxime formation are investigated, showing that the difunctionalization reaction has a good adaptability to such reactants containing a range of substituents. This is important in the actual production process. It was found that proton transfer in the final tautomerism step involving transformation of a nitroso intermediate into an oxime is the rate-limiting step. The solvent effect did not influence the rate-limiting step significantly. Compared with direct proton transfer in a vacuum, the energy barrier of the final tautomerism step decreased from 57.80 kcal mol−1 in vacuum to 12.98 kcal mol−1 in water occurring via mediated proton transfer, which declines by 77.5%. When water participates in the rate-limiting steps in organic solvents, the energy barrier also decreases significantly, which indicates that a small amount of water in the organic solvent is conducive to the reaction.

Electrochemical Trifluoromethylation of Thiophenols with Sodium Trifluoromethanesulfinate

We developed an electrochemical trifluoromethylation of thiophenols without the use of metal catalysts and oxidants. This reaction features mild reaction conditions, readily available substrate, as well as moderate to good yields. In addition, this protocol can be easily scaled up with moderate efficiency.

Metal-Free Trifluoromethylthiolation of Arylazo Sulfones

A visible-light-driven protocol for the synthesis of aryl trifluoromethyl thioethers under photocatalyst- and metal-free conditions has been pursued. The procedure exploits the peculiar properties of arylazo sulfones (having electron-rich or electron-poor substituents on the (hetero)aromatic ring) as photochemical precursors of aryl radicals and S-trifluoromethyl arylsulfonothioates as easy-to-handle trifluoromethylthiolating agents.

Visible-Light-Promoted Cross-Coupling Reactions of Aryldiazonium Salts with S-Methyl-d3 Sulfonothioate or Se-Methyl-d3 Selenium Sulfonate: Synthesis of Trideuteromethylated Sulfides, Sulfoxides, and Selenides

A novel visible-light-photocatalytic deuterated thiomethylation/methylselenation of aryldiazonium salts utilizing S/Se-methyl-d₃ sulfonothioate has been developed. The mild conditions and the various functional groups provide a green protocol for the efficient and rapid introduction of the S-CD₃ or Se-CD₃ group with useful levels of deuterium content (>91% D). Trideuteromethyl sulfoxides have also been successfully chemoselectively observed by simple atmospheric changes under photocatalytic conditions.

Recent application of visible-light induced radicals in C-S bond formation

The sulphur centered radicals, produced from various organic compounds, in high efficiency by single-electron-transfer (SET) oxidation. These radicals are highly reactive intermediates having various applications in the construction of organosulphur compounds in the field of synthetic organic chemistry. These S-centred radical-mediated organic transformations have been achieved using photoredox catalysts, including organic dyes and transition metal catalysts, as well as in the absence of any catalyst. Compared with previous methods, photoredox catalysis is inexpensive and features the advantages of being environmentally benign, highly efficient and easy to use. This review focuses on recent developments in the photocatalyzed carbon-sulphur bond formation.

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

Fluorine chemistry plays an increasingly important role in pharmaceutical, agricultural, and materials industries. The incorporation of fluorine-containing groups into organic molecules can improve their chemical and physical properties, which attracts continuous interest in organic synthesis. Among various reported methods, transition-metal-catalyzed fluorination/fluoroalkylation has emerged as a powerful method for the construction of these compounds. This review attempts to describe the major advances in the transition-metal-catalyzed incorporation of fluorine, trifluoromethyl, difluoromethyl, trifluoromethylthio, and trifluoromethoxy groups reported between 2011 and 2019.

Nickel-Catalyzed Defluorinative Reductive Cross-Coupling Reaction of gem-Difluoroalkenes with Thiosulfonate or Selenium Sulfonate

A nickel-catalyzed defluorinative reductive cross-coupling of gem-difluoroalkenes with thiosulfonate or selenosulfonates is described. The reaction involves the formation of thiolated or selenylated monofluoroolefins via regioselective C-F bond cleavage and C-S or C-Se bond formation and features easily available substrates, mild reaction conditions, and high E-selectivity. One of the derivatives by further cross coupling with PhMgBr exhibited an aggregation-induced emission enhancement effect.

Use of ArSO2SRf reagents: an efficient tool for the introduction of SRf moieties

In recent years, a renewal of interest was shown to the quest for new synthetic solutions to directly introduce emergent fluorinated groups (SRf) onto molecules. In this context, a new generation of reagents (ArSO2SRf) as efficient sources of SCF3, SCF2H and more generally SRf groups, was designed. Hence, potent solutions were developed for the synthesis of SRf-containing molecules, compounds of interest for drug and agrochemical research. This review highlights the recent advances made in the synthesis and the use of this new class of reagents, considerably extending the portfolio of tools for the direct introduction of SRf moieties.

Facile synthesis of α-trifluoromethylthio phosphonium ylides with a constrained trifluoromethylthiooxide via a proton-transfer procedure

Synthesis of α-trifluoromethylthio(CF₃S–)phosphonium ylides is easily accomplished with a constrained trifluoromethylthiooxide via a proton-transfer procedure without extra base.

Visible light enabled γ-trifluoromethylation of Baylis–Hillman acetates: stereoselective synthesis of trisubstituted alkenes

Metal-free γ-trifluoromethylation of Baylis–Hillman acetates is reported using Langlois’ reagent under visible light photoredox catalysis.