Suzuki–Miyaura cross-coupling reaction of aryl bromides and chlorides with phenylboronic acid under aerobic conditions catalyzed by palladium complexes with thiosemicarbazone ligands

For the first time, palladium complexes with salicylaldehyde thiosemicarbazones were applied as catalyst precursors to the Suzuki–Miyaura reaction. These air and moisture stable phosphine-free systems efficiently catalyze the cross-coupling of aryl bromides and chlorides (from electron rich to electron poor) with phenylboronic acid in DMF/H2O at 100 °C for 24 h, using Na2CO3 as base, without addition of free ligand or any promoting additive, and under aerobic conditions no significant homocoupling of phenylboronic acid to unsubstituted biphenyl was observed.