Visible-light induced di- and trifluoromethylation of N-benzamides with fluorinated sulfones for the synthesis of CF2H/CF3-containing isoquinolinediones.

A general visible light induced direct difluoromethylation of N-methacryloyl benzamides by using difluoromethyl sulfone was developed. In addition, photoredox-catalyzed trifluoromethylation of N-methacryloyl benzamides with trifluoromethyl sulfone via a similar radical process was also achieved. This method allows for an efficient and practical synthesis of a variety of CF2H/CF3-containing isoquinoline-1,3(2H,4H)-diones in moderate to good yields. The reaction features mild reaction conditions, operational simplicity, and a broad substrate scope.