Suzuki-Miyaura coupling reaction using pentafluorophenylboronic acid

[GRAPHICS] We have found new conditions for the Suzuki-Miyaura coupling reaction applicable to pentafluorophenylboronic acid (C6F5B(OH)2) (1), which is an inactive substrate under normal conditions. The reactions of 1 with phenyl iodide or bromide under Pd(PPh3)(4)/CsF/Ag2O or Pd-2(dba)(3)/P(t-Bu)(3)CsF/Ag2O catalytic system conditions gave 2,3,4,5,6-pentafluoro-1,1'-biphenyl (3a) in more than 90% yields. Combination of CsF and Ag2O was essential for promoting these reactions.