Cascade Oxidative Trifluoromethylthiolation and Cyclization of 3-Alkyl-1-(2-(alkynyl)phenyl)indoles
Thikhamporn Uppalabat, Nattawoot Hassa, Natthapat Sawektreeratana, Pawaret Leowanawat, Pattarapapa Janthakit, Phattananawee Nalaoh, Vinich Promarak, Darunee Soorukram, Vichai Reutrakul, Chutima Kuhakarn
Abstract
Persulfate-promoted radical cascade trifluoromethylthiolation and cyclization of 3-alkyl-1-(2-(alkynyl)phenyl)indoles with AgSCF 3 were investigated. This protocol provides a novel route to CF 3 S-substituted indolo[1,2- a ]quinoline-7-carbaldehydes and CF 3 S-substituted indolo[1,2- a ]quinoline-7-methanone derivatives via the formation of the C–SCF 3 bond and C–C bond and benzylic carbon oxidation in a single step. This reaction can accommodate a broad range of functional groups. The single-crystal X-ray diffraction data confirm the chemical structure of the product. A scale-up experiment and radical inhibition experiments were operated in the reaction system. Photophysical properties of some selected 5-((trifluoromethyl)thio)indolo[1,2- a ]quinoline-7-carbaldehydes were studied by UV–visible and fluorescence spectroscopy.