2,2-Difluoroethenyl 4-Methylbenzene-1-sulfonate

• 4-Biphenylboronic Acid [B2294]
• 2,2-Difluorovinyl Tosylate [D6545]
• Tris(dibenzylideneacetone)dipalladium(0) (= Pd₂dba₃) [T2184]
• Tricyclohexylphosphonium Tetrafluoroborate (= PCy₃·HBF₄) [T2585]
• Tripotassium Phosphate
• THF

4-Biphenylboronic acid (100 mg, 0.51 mmol), 2,2-difluorovinyl tosylate (177 mg, 0.76 mmol), Pd₂(dba)₃ (11.5 mg, 0.01 mmol), and PCy₃·HBF₄ (9.2 mg, 0.03 mmol) were added into the reaction vessel. To this, tripotassium phosphate (182 mg, 0.86 mmol) in water (670 µL) and THF (3.4 mL) were added subsequentially. The vessel was purged with nitrogen and the mixture was stirred at 70 °C for 20 hours. Then the reaction mixture was filtered under vacuum to remove the insoluble, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane) to afford 4-(2,2-difluorovinyl)biphenyl (93.8 mg, 88% yield) as a white solid.

The reaction was monitored by TLC (hexane, Rf = 0.4) and UPLC-MS.

4-(2,2-Difluorovinyl)biphenyl

¹H NMR (400 MHz, CDCl₃); δ 7.61- 7.57 (m, 4H), 7.46- 7.33 (m, 5H), 5.32 (dd, J = 26.4, 3.6 Hz, 1H).

• Direct Vinylation and Difluorovinylation of Arylboronic Acids Using Vinyl- and 2,2-Difluorovinyl Tosylates via the Suzuki-Miyaura Cross Coupling
  • T. M. Gøgsig, L. S. Søbjerg, A. T. Lindhardt, K. L. Jensen, T. Skrydstrup, J. Org. Chem. 2008, 73, 3404.