Abstract A novel copper-catalyzed arylation of arylboronic acids with aldehydes under oxygen atmosphere was achieved in the presence of Cu (OTf) 2 and Xantphos, affording diaryl ketone derivatives in moderate to good yields. The efficiency of this reaction was demonstrated by the compatibility with fluoro, bromo, chloro, nitro, methylsulfonyl, and trifluoromethyl groups.