We report a simple and efficient procedure for Suzuki–Miyaura reactions in aqueous media catalysed by amidophosphine‐stabilized palladium complexes trans‐{L3PPh2}2PdCl2 (3), trans‐{L3PPhtBu}2PdCl2 (4), [Pd(η3‐C3H5)(L3PPh2)Cl] (5) and {Pd[2‐(Me2NCH2)C6H4](L3PPh2)Cl} (6). The acidity of the NH proton in complexes 3, 4, 5, 6 plays an important role in their catalytic activity. In addition, the palladium complexes cis‐{L1PPh2}PdCl2 (1) and trans‐{L2PPh2}2PdCl2 (2) stabilized by phosphines containing Y,C,Y‐chelating ligands L1,2 have also been found to be useful catalysts for Suzuki–Miyaura reactions in aqueous media. The method can be effectively applied to both activated and deactivated aryl bromides yielding high or moderate conversions. The catalytic activity of couplings performed in pure water increases when utilizing a Pd complex with more acidic NH protons. A decrease of palladium concentration from 1.0 to 0.5 mol% does not lead to a substantial loss of conversion. In addition, Pd complex 1 can be efficiently recovered using two‐phase system extraction. Copyright © 2016 John Wiley & Sons, Ltd.

1 H, 13 C, 31 P NMR spectroscopy and ESI-MS. The molecular structures of 3,4 and 6 were also determined by X-ray diffraction analysis. The catalytic activity of complexes 3-6 was evaluated in the Suzuki-Miyaura cross-coupling reaction.

A ligand‐free heterogeneous palladium on charcoal (Pd/C)‐catalyzed Suzuki‐Miyaura cross‐coupling has been performed. The series of substituted p‐terphenyls were prepared in very good yields without exclusion of air and with low catalyst loadings. Moreover, the developed environmentally benign and scalable protocol enables to use electron poor and sterically hindered boronic acids.magnified image

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H 3 ]SbPh 2 }PtCl 2 (6) as the result of different ability of the starting compounds 1-3 to complex platinum centre. Compounds 1-6 were characterized by 1 H, 13 C and 31 P NMR spectroscopy and electrospray ionization mass spectrometry, and molecular structures of 3-6 were determined by X-ray diffraction analysis. The substitution reactions of complexes 4-6 were also studied. The reaction of 5 and 6 with NaI yielded complexes {[2,6-(Me 2 NCH 2 ) 2 C 6 H 3 ]PPh 2 }PtI 2 (7) and {[2,6-(Me 2 NCH 2 ) 2 C 6 H 3 ]SbPh 2 }PtI 2 (8), while the same reaction of 4 with NaI did not proceed. As the compounds 7 and 8 structurally resemble cisplatin, complex {{[2-(Me 2 NCH 2 )-6-(Me 2 NHCH 2 )C 6 H 3 ]PPh 2 }PtCl 2 } + Cl À (9) was prepared as water-soluble platinum complex. The cytotoxic effect of complex 9 was evaluated on human T-lymphocytic leukemia cells MOLT-4 (IC 50 = 27.6 AE 1.8 mmol l À1 ) and human promyelocytic leukemia HL-60 (IC 50 = 55.9 AE 4.9 mmol l À1 ).