Pinpoint-fluorinated phenanthrene synthesis based on CF bond activation of difluoroalkenes

• 1,1-Difluoro-1-alkenes bearing a biphenyl skeleton were treated with a cationic palladium(II) catalyst.
• The Friedel–Crafts-type cyclizations of difluoroalkenes afforded pinpoint-fluorinated phenanthrenes via CF bond activation.
• The packing structure of the products was investigated by single-crystal X-ray structure analysis.
• Columnar and layer structures in the solid state were observed.

Treatment with a cationic palladium(II) catalyst promoted the Friedel–Crafts-type cyclization of 1,1-difluoro-1-alkenes bearing a biphenyl skeleton to afford regioselectively fluorinated (pinpoint-fluorinated) phenanthrenes via CF bond activation. The obtained pinpoint-fluorinated phenanthrenes were observed to be organized by π–π and CH⋯F interactions to exhibit columnar and layer structures in the solid state.

Treatment with a cationic palladium(II) catalyst promoted the Friedel–Crafts-type cyclization of 1,1-difluoro-1-alkenes bearing a biphenyl skeleton to afford regioselectively fluorinated (pinpoint-fluorinated) phenanthrenes via CF bond activation. The obtained pinpoint-fluorinated phenanthrenes were observed to be organized by π–π and CH⋯F interactions to exhibit columnar and layer structures in the solid state.Figure optionsDownload as PowerPoint slide