2‑Trifluoromethylated Indoles via Radical Trifluoromethylation of Isonitriles

Either two or three C–C bonds are formed in the synthesis of 2-trifluoromethylindoles starting with readily prepared isonitriles and the Togni reagent as CF₃ radical precursor. These transformations occur in the absence of transition metal, and products are obtained in moderate to good yields with excellent diastereoselectivity

Sodium-Ketyl Radical Anions by Reverse Pinacol Reaction and Their Coupling with Iodoarenes

Transition-metal-free C–C bond formation between aryl iodides and pinacols is presented. Pinacols are readily transformed by deprotonation with NaH to their Na-pinacolates. C–C-bond homolysis at room temperature generates in situ the corresponding Na-ketyl radical anions which react with various aryl iodides in a homolytic aromatic substitution reaction to form tertiary Na-alcoholates. Protonation eventually provides tertiary alcohols in an unprecedented route

Regio- and Stereoselective Cyanotriflation of Alkynes Using Aryl(cyano)iodonium Triflates

A novel, mild, and versatile approach for regioselective <i>syn</i>-addition of both the CN and OTf groups of aryl­(cyano)­iodonium triflates to alkynes is described. The reaction uses Fe-catalysis and can be conducted in gram scale. Products of the vicinal cyanotriflation can be stereospecifically readily further functionalized, rendering the method highly valuable

Perfluoroalkylation of Aryl‑<i>N</i>,<i>N</i>‑dimethyl Hydrazones Using Hypervalent Iodine(III) Reagents or Perfluoroalkyl Iodides

Radical trifluoromethylation of aryl <i>N</i>,<i>N</i>-dimethyl hydrazones using TBAI as an initiator and Togni’s reagent as a trifluoromethyl radical source is described. Cascades proceed via electron-catalysis; this approach is generally more applicable to hydrazone perfluoroalkylation using perfluoroalkyl iodides as the radical precursors in combination with a base under visible-light initiation

1‑Trifluoromethylisoquinolines from α‑Benzylated Tosylmethyl Isocyanide Derivatives in a Modular Approach

The preparation of various 1-trifluoromethylisoquinolines from α-benzylated tosylmethyl isocyanide derivatives and the commercial Togni reagent using a radical cascade is reported. The starting isocyanides are readily prepared in a modular sequence from commercial tosylmethyl isocyanide via sequential double α-alkylation, and the radical reaction proceeds under mild conditions with high efficiency without any transition-metal catalyst via electron catalysis. This valuable protocol has been successfully applied to the total synthesis of CF₃-mansouramycin B

Reaction of Arynes with Vinyl Sulfoxides: Highly Stereospecific Synthesis of <i>ortho</i>-Sulfinylaryl Vinyl Ethers

The reaction of in situ generated arynes with aryl vinyl sulfoxides provides <i>ortho</i>-arylsulfinylaryl vinyl ethers via aryne σ-bond insertion into the S–O-bond and concomitant stereospecific S–O-vinyl migration. The cascade allows preparing di- or trisubstituted vinyl ethers with excellent stereospecificity. The reactions proceed under mild conditions, the substrate scope is broad, and the products obtained are valuable

Copper-Catalyzed Intermolecular Aminoazidation of Alkenes

Copper-catalyzed intermolecular aminoazidation of alkenes is described. This novel methodology provides an efficient approach to vicinal amino azides which can easily be transformed into other valuable amine derivatives. The commercially available <i>N</i>-fluorobenzenesulfonimide (NFSI) is used as a nitrogen-radical precursor and TMSN₃ as the N₃ source. Yields are moderate to excellent, and for internal alkenes aminoazidation occurs with excellent diastereoselectivity

Stereoselective Radical Azidooxygenation of Alkenes

Radical azidooxygenation of various alkenes is described. A readily prepared N₃-iodine(III) reagent acts as a clean N₃-radical precursor. Radical generation is achieved with TEMPONa acting as a mild organic reducing reagent. The C-radical generated after N₃-radical addition is efficiently trapped by <i>in situ</i> generated TEMPO. Yields are good to excellent, and for cyclic systems azidooxygenation occurs with excellent diastereoselectivity

Stereoselective Radical Azidooxygenation of Alkenes

Radical azidooxygenation of various alkenes is described. A readily prepared N₃-iodine(III) reagent acts as a clean N₃-radical precursor. Radical generation is achieved with TEMPONa acting as a mild organic reducing reagent. The C-radical generated after N₃-radical addition is efficiently trapped by <i>in situ</i> generated TEMPO. Yields are good to excellent, and for cyclic systems azidooxygenation occurs with excellent diastereoselectivity

9‑Silafluorenes via Base-Promoted Homolytic Aromatic Substitution (BHAS) – The Electron as a Catalyst

Transition-metal-free intramolecular radical silylation of 2-diphenyl­silylbiaryls via base-promoted homolytic aromatic substitution (BHAS) to give 9-silafluorenes is reported. 2-Diphenyl­silylbiaryls are readily prepared, and cross dehydrogenative silylation occurs with <i>tert</i>-butylhydro­peroxide (TBHP) as a cheap stoichiometric oxidant in the presence of a small amount of tetra­butyl­ammonium iodide (TBAI) as an initiator. These cyclizations are catalyzed by the electron