Catalyst-free direct C H trifluoromethylation of indoles with Togni’s reagent

Pd-Catalyzed Direct C7 Trifluoromethylation of Indolines with Umemoto’s Reagent

“…However, direct trifluoromethylation of indole or indoline derivatives is still challenging. Recently, various strategies to introduce the CF 3 group at C2–C4 positions of indoles have been developed by organic chemists (Scheme a) . However, most of these approaches have disadvantages of long reaction time, ,, poor regioselectivity, − difficult-to-handle or toxic reagents, and involving additional ligands. , While examples of the introduction of a CF 3 group into heteroarenes with a stable and easy to handle trifluoromethyl source are still scarce, among those limited examples, direct trifluoromethylation of heteroarenes with versatile trifluoromethylation reagents via transition-metal (TM)-catalyzed C–H bond activation is regarded as a robust and direct methodology .…”