Photoredox-Catalyzed Bromodifluoromethylation of Alkenes with (Difluoromethyl)triphenylphosphonium Bromide

Trifluoromethanesulfonic Anhydride as a Low-Cost and Versatile Trifluoromethylation Reagent

A large number of reagents have been developed for the synthesis of trifluoromethylated compounds. However, an ongoing challenge in trifluoromethylation reaction is the use of less expensive and practical trifluoromethyl sources. We report herein the unprecedented direct trifluoromethylation of (hetero)arenes using trifluoromethanesulfonic anhydride as a radical trifluoromethylation reagent by merging photoredox catalysis and pyridine activation. Furthermore, introduction of both the CF₃ and OTf groups of the trifluoromethanesulfonic anhydride into internal alkynes to access tetrasubstituted trifluoromethylated alkenes was achieved. Since trifluoromethanesulfonic anhydride is a low-cost and abundant chemical, this method provides a cost-efficient and practical route to trifluoromethylated compounds.

Electrochemical Difluoromethylarylation of Alkynes

An unprecedented radical difluoromethylarylation reaction of alkynes has been developed by discovering a new difluoromethylation reagent, CF₂HSO₂NHNHBoc. This air-stable and solid reagent can be prepared in one step from commercially available reagents CF₂HSO₂Cl and NH₂NHBoc. The CF₂H radical, generated through ferrocene-mediated electrochemical oxidation, participates in an unexplored alkyne addition reaction followed by a challenging 7-membered ring-forming homolytic aromatic substitution step to afford fluorinated dibenzazepines.

A Zn(OTf)2 catalyzed Ugi-type reaction of 3-(2-isocyanoethyl)indoles with indole-derived ketimines: rapid access to hexacyclic spiroindolines

A Zn(OTf)₂ catalyzed Ugi-type reaction of 3-(2-isocyanoethyl)indoles and indole-derived ketimines was developed for the synthesis of hexacyclic spiroindolines featuring three stereocenters including two quaternary stereocenters.

Photoredox 1,2-dicarbofunctionalization of unactivated alkenes via tandem radical difluoroalkylation and alkynyl migration

Visible-light-mediated tandem radical difluoroalkylation and alkynylation of unactivated alkenes is described. It comprises a mild C–C bond activation via intramolecular 1,4-radical alkynyl migration.

Synthesis of 3-CF2-Containing Chromones via a Visible-Light-Induced Radical Cascade Reaction of o-Hydroxyaryl Enaminones

A general and efficient visible-light-induced CF₂ radical-based cascade reaction of o-hydroxyaryl enaminones has been described. This protocol afforded the corresponding functionalized 3-CF₂-containing chromones in generally good yields under mild reaction conditions. The use of NaHSO₃, which has both basicity and reducibility, efficiently suppressed the formation of two byproducts, 4H-chromen-4-one and 3-bromo-4H-chromen-4-one.

Metal-free di- and tri-fluoromethylation of alkenes realized by visible-light-induced perylene photoredox catalysis

Regioselective amino-difluoromethylation of aromatic alkenes via C(sp³)-CF₂H and C(sp³)-N bond formation with the C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C moiety has been achieved in a single operation by visible-light photoredox catalysis. The combination of a shelf-stable and easy-to-handle sulfonium salt, S-difluoromethyl-S-di(p-xylyl)sulfonium tetrafluoroborate, and perylene catalysis is the key to the successful transformation. Furthermore, this noble metal-free protocol allows for the photocatalytic trifluoromethylation of alkenes.

China's flourishing synthetic organofluorine chemistry: innovations in the new millennium

The new millennium has witnessed the rapid development of synthetic organofluorine chemistry all over the world, and chemists in China have made significant contributions in this field. This review aims to provide a brief introduction to China's primary innovations from 2000 to early 2017, covering fluorination, fluoroalkylation, fluoromethylthiolation, fluoroolefination and polyfluoroarylation, as well as synthesis with fluorinated building blocks. Recent advances in the chemistry of difluorocarbene and the chemistry of carbon–fluorine bond activation are also discussed. As a conclusion, the review ends with some personal perspectives on the future development of China's synthetic organofluorine chemistry.

Visible-light induced di- and trifluoromethylation of N-benzamides with fluorinated sulfones for the synthesis of CF2H/CF3-containing isoquinolinediones

A photocatalytic radical di- or trifluoromethylation/cyclization of methacryloyl benzamides with fluorinated sulfones provided an efficient route to CF₂H/CF₃-containing isoquinoline-1,3(2H,4H)-diones.

Visible-light-mediated direct difluoromethylation of alkynoates: synthesis of 3-difluoromethylated coumarins

A photoredox-catalyzed direct difluoromethylation of alkynoates has been developed.

Visible-light-mediated radical cascade reaction: synthesis of 3-bromocoumarins from alkynoates

The development of a visible-light mediated bromo radical addition/spirocyclization/ester migration cascade reaction to generate 3-bromocoumarins from alkynoates is reported.

Nucleophilic 1,1-Difluoroethylation with Fluorinated Phosphonium Salt

The fluorinated phosphonium salt (Ph3P+CF2CH3 BF4-) was shown to act as a nucleophilic 1,1-difluoroethylation agent to enable difluoroethylation of aldehydes and imines.

Visible-Light-Driven, Radical-Triggered Tandem Cyclization of o-Hydroxyaryl Enaminones: Facile Access to 3-CF2 /CF3-Containing Chromones

A practical and straightforward synthetic route to construct a variety of 3-CF₂/CF₃-containing chromones via photoredox catalysis was developed. This novel protocol features a visible-light-induced radical-triggered tandem cyclization.

Mechanism of Silver-Mediated Geminal Difluorination of Styrenes with a Fluoroiodane Reagent: Insights into Lewis-Acid-Activation Model

Fluorination mediated by the cyclic hypervalent fluoroiodane reagent (1) often requires an exogenous Lewis acid. The widely accepted Lewis-acid-activation model is that a given Lewis acid binds to the oxygen atom of 1 (O-coordination) to polarize the I-O bond. Computational studies of silver-mediated geminal difluorination of styrenes with 1 reveal a new "F-coordination" model that is energetically much preferred over the commonly accepted "O-coordination" model. The calculations rationalize the regioselective formation of the geminal difluorination product.

Cascade Photoredox/Iodide Catalysis: Access to Difluoro-γ-lactams via Aminodifluoroalkylation of Alkenes

The novel cascade photoredox/iodide catalytic system enables the alkene to serve as a radical acceptor capable of achieving aminodifluoroalkylation of alkenes. Cheap iodide salts play a vital role in this reaction, which could tune carbocation reactivity through reversible C-I bond formation for controlling reaction selectivity, and a series of competitive reactions are completely eliminated in the presence of multiple reactivity pathways. The present dual catalytic protocol affords a very convenient method for direct synthesis of various difluoro-γ-lactams from simple and readily available starting materials under mild reaction conditions.

Recent advances in photoinduced trifluoromethylation and difluoroalkylation

Recent advances in photoinduced trifluoromethylation and difluoroalkylation under photocatalysis are summarized. Most of the photoredox reactions proceed efficiently under mild conditions with simple operation. Various fluorinated reagents are developed and applied in different transformations.

Visible-light-mediated radical oxydifluoromethylation of olefinic amides for the synthesis of CF2H-containing heterocycles

The visible-light-mediated oxydifluoromethylation of olefinic amides with difluoromethyl sulfones has been explored.

Merging photoredox with copper catalysis: decarboxylative difluoroacetylation of α,β-unsaturated carboxylic acids with ICF2CO2Et

A novel decarboxylative difluoroacetylation of α,β-unsaturated carboxylic acids via a combination of visible light photocatalysis and cooper catalysis is reported.