Photocatalytic Alkylation of α-(Trifluoromethyl)Styrenes with Potassium Xanthogenates

A protocol for the coupling of potassium xanthogenates with α-(trifluoromethyl)styrenes in the presence of triethyl phosphite is reported. The reaction is carried out under blue light irradiation in the presence of organic photocatalyst 3DPAFIPN. The reaction proceeds via formation of alkyl radicals from readily available xanthogenate salts via oxidative desulfurization and cleavage of the carbon–oxygen bond assisted by triethyl phosphite

Dual Photoredox/Copper Catalyzed Fluoroalkylative Alkene Difunctionalization

A method for performing radical difunctionalization of alkenes using fluorinated halides and a nucleophilic component (thiolate and iodide anions) is described. These nucleophilic fragments serve as redox active groups for performing subsequent transformations. The difunctionalization reaction involves photoredox generation of fluorinated radicals, their addition to the double bond followed by copper-promoted C–S or C–I bond formation. The primary products can be further coupled with silyl enol ethers, α-(trifluoromethyl)styrenes, and trimethylsilyl cyanide affording a variety of fluorinated compounds

Photoredox Catalyzed Dealkylative Aromatic Halogen Substitution with Tertiary Amines

A reaction of aromatic halides bearing electron-withdrawing groups with tertiary amines in the presence of an iridium catalyst under blue light irradiation is described. Products of the aromatic substitution of the halide by the dialkylamino fragment are obtained. The interaction of aryl radicals with tertiary amines to generate zwitterionic radical species is believed to be the key factor responsible for the reaction efficiency

Synthesis of <i>gem</i>-Difluorinated Hydroxypyrrolidines

A method for the synthesis of 3-hydroxy-4,4-difluoro­pyrrolidines from α,α-difluoro-β-bromoketones is described. The reaction involves methylenation of the carbonyl group with tetrahydro­thiophenium ylide followed by coupling with primary amines

Visible light-mediated difluoroalkylation of electron-deficient alkenes

A method for the reductive difluoroalkylation of electron-deficient alkenes using 1,1-difluorinated iodides mediated by irradiation with blue light is described. The reaction involves radical addition of 1,1-difluorinated radicals at the double bond followed by hydrogen atom transfer from sodium cyanoborohydride

Silicon Reagent with Functionalized Tetrafluoroethylene Fragments: Preparation and Coupling with Aldehydes

A new fluorinated silicon reagent bearing a functionalized tetrafluoroethylene fragment was prepared from two CF₂ building blocks: ethyl bromodifluoroacetate and (bromodifluoromethyl)­trimethylsilane. The key C–C bond-forming step involves a difluorocarbene addition/cyclopropane rearrangement sequence. The silicon reagent was coupled with aldehydes and reactive azomethines in the presence of potassium fluoride

Difluoro(trimethylsilyl)acetonitrile: Synthesis and Fluoroalkylation Reactions

A new silicon reagent, difluoro­(trimethylsilyl)­acetonitrile, was prepared by insertion of difluorocarbene into silyl cyanide. The obtained silane served as a good cyanodifluoromethylating reagent toward aldehydes, <i>N</i>-tosylimines, <i>N</i>-alkylimines, and enamines under basic or acidic conditions