Trifluoromethylation of aromatic alkenes by visible-light-driven photoredox catalysis: Direct conversion of alkenes to 3-trifluoromethyl-1-propenyl and 1,3-bis(trifluoromethyl)-1-propenyl derivatives

• Trifluoromethylation of alkenes is promoted by visible-light photoredox catalysis.
• Umemoto's reagent serves as a CF3 radical precursor.
• Photocatalytic trifluoromethylation produces 4,4,4-trifluoro-2-aryl-1-butenes.
• Double trifluoromethylation produces 1,1,1,5,5,5-hexafluoro-3-aryl-2-pentenes.

Photoredox-catalyzed trifluoromethylation of alkenes using Umemoto's reagent as a CF3 source under visible light irradiation has been developed. A Ru photocatalyst, [Ru(bpy)3](PF6)2 (bpy = 2,2′-bipyridine), is useful for the present trifluoromethylation and preferable formation of 3-trifluoromethyl-1-propenyl derivatives is observed. Use of an excess amount of Umemoto's reagent readily induces double trifluoromethylation of electron-rich alkenes, resulting in 1,3-bis(trifluoromethyl)-1-propenyl skeleton.

Photoredox-catalyzed trifluoromethylation of alkenes with Umemoto's reagent results in mono- and bis-trifluoromethylation to afford 4,4,4-trifluoro-2-aryl-1-butene and 1,1,1,5,5,5-hexafluoro-3-aryl-2-pentene derivatives.Figure optionsDownload as PowerPoint slide