Visible-light-induced mesoporous graphitic carbon nitride-catalyzed trifluoromethylation and perfluoroalkylation of 4-aminocoumarins†
Abstract
A heterogeneous photocatalytic 3-trifluoromethylation and 3-perfluoroalkylation of 4-aminocoumarins was realized from 4-aminocoumarins and CnF2n+1SO2Na under mild conditions using mesoporous graphitic carbon nitride (mpg-C3N4) as an effective and recyclable photocatalyst without any other additives. This transition-metal-free procedure shows wide substrate scope with air as a green oxidant affording 3-trifluoromethylated/perfluoroalkylated 4-aminocoumarins in moderate to good yields.