Effect of imidazolinium salts bearing hydroxy substituents on palladium-catalysed Suzuki–Miyaura and Heck coupling reactions

Morel, A., Trzeciak, A. (2016). Effect of imidazolinium salts bearing hydroxy substituents on palladium-catalysed Suzuki–Miyaura and Heck coupling reactions. French-Ukrainian Journal of Chemistry, 4(1), 76–84. https://doi.org/10.17721/fujcV4I1P76-84

Palladium anionic complexes with imidazolinium cations containing hydroxyl substituents were used as catalyst precursors in the Suzuki–Miyaura and the Heck cross-coupling. High activity of anionic complexes was noted in the Suzuki–Miyaura reaction of 2-bromotoluene with phenylboronic acid at 40 oC in 2-propanol and a 2-propanol/water mixture using conventional heating or microwaves. Similarly, bromonaphtalene and iodonaphtalene reacted efficiently with naphtylboronic acid and 4-methylnaphtylboronic acid. A remarkably lower activity was noted when anionic palladium complexes were employed in the Heck coupling of 2,3-dihydrofuran with iodobenzene. An increase in conversion in the Heck reaction was achieved when Pd(OAc)2 was used as a catalyst precursor together with imidazolinium salts as co-catalysts.