(A) Heterobiaryls in drugs. (B) Heterobiaryls via metal-catalyzed cross-coupling reactions. R denotes a general organic group; Hal, halogen substituent. (C) Test system for heterobiaryl synthesis via phosphorus ligand coupling reactions. Ph, phenyl; Me, methyl; Et, ethyl; Tf, trifluoromethylsulfonyl; DBU, 1,8-diazabicyclo[5.4.0] undec-7-ene; rt, room temperature.