Efficient copper-catalyzed trifluoromethylation of aromatic and heteroaromatic iodides: the beneficial anchoring effect of borates

Cross-Coupling of [2-Aryl-1,1,2,2-tetrafluoroethyl](trimethyl)silanes with Aryl Halides

The synthesis of arylCF2CF2SiMe3 and their reactivity in cross-coupling reactions with aryl iodides and aryl bromides to afford a range of 1,1,2,2-tetrafluoro-1,2-arylethanes is reported. The use of pyridine as an alternative to phenanthroline, and the ability to carry out the reaction at 60 °C or room temperature are the key features of this Cu-Ag mediated cross-coupling methodology. The chemistry is compatible with (hetero)aryl halides, offering a platform to develop products of interest in material and medicinal chemistry.

Ligand-Controlled Regioselective Copper-Catalyzed Trifluoromethylation To Generate (Trifluoromethyl)allenes

"Cu-CF3" species have been used historically for a broad spectrum of nucleophilic trifluoromethylation reactions. Although recent advancements have employed ligands to stabilize and harness the reactivity of this key organometallic intermediate, the ability of a ligand to differentiate a regiochemical outcome of a Cu-CF3-mediated or -catalyzed reaction has not been previously reported. Herein, we report the first example of a Cu-catalyzed trifluoromethylation reaction in which a ligand controls the regiochemical outcome. More specifically, we demonstrate the ability of bipyridyl-derived ligands to control the regioselectivity of the Cu-catalyzed nucleophilic trifluoromethylation reactions of propargyl electrophiles to generate (trifluoromethyl)allenes. This method provides a variety of di-, tri-, and tetrasubstituted (trifluoromethyl)allenes, which can be further modified to generate complex fluorinated substructures.

Efficient direct 2,2,2-trifluoroethylation of indoles via C–H functionalization

Metal free direct trifluoroethylation of unprotected indoles at position 3 via C–H functionalization is presented: straightforward synthesis and DFT studies.