Visible-light photoredox-catalyzed radical aryldifluoromethylation of N-arylacrylamides with S-(difluoromethyl)sulfonium salt

A facile and highly efficient visible-light photoredox-catalyzed protocol for aryldifluoromethylation of acrylamides was developed using S-(difluoromethyl)sulfonium salt as the difluoromethyl source. With this method, pharmaceutically interesting CF2H-containing oxindoles were readily accessed from N-arylacrylamides, and this method featured mild reaction conditions, a broad scope of substrates, good tolerance of functional groups, and good to excellent yields. Control experiments revealed that this protocol proceeded through a difluoromethylation/cyclization cascade process.

Automated summary

A facile and highly efficient protocol for aryldifluoromethylation of acrylamides was developed using visible-light photoredox catalysis with S-(difluoromethyl)sulfonium salt as the difluoromethyl source. This method enables the synthesis of pharmaceutically interesting CF2H-containing oxindoles from N-arylacrylamides, and demonstrates mild reaction conditions, a broad scope of substrates, good tolerance of functional groups, and high yields. Control experiments indicate that the protocol proceeds through a difluoromethylation/cyclization cascade process.