Nickel(II) complexes containing ONS donor ligands: Synthesis, characterization, crystal structure and catalytic application towards C-C cross-coupling reactions

Abstract

Nickel(II) complexes containing thiosemicarbazone ligands [Ni(L) 2 ] (1-3) (L = 9,10-phenanthrenequinonethiosemicarbazone (HL 1 ), 9,10-phenanthrenequinone-N-methylthio semicarbazone (HL 2 ) and 9, 10-phenanthrenequinone-N-phenylthiosemicarbazone (HL 3 )) have been synthesized and characterized by elemental analysis and spectroscopic (IR, UV-Vis, 1 H, 13 C-NMR and ESI mass) methods. The molecular structures of complexes 1 and 2 were identified by means of single-crystal X-ray diffraction analysis. The analysis revealed that the complexes possess a distorted octahedral geometry with the ligand coordinating in a uni-negative tridentate ONS fashion. The catalytic activity of complexes towards some C-C coupling reactions (viz., KumadaCorriu, Suzuki-Miyaura and Sonogashira) has been examined. The complexes behave as efficient catalysts in the Kumada-Corriu and Sonogashira coupling reactions rather than Suzuki-Miyaura coupling.

Thiosemicarbazone Complexes of Transition Metals as Catalysts for Cross-Coupling Reactions

“…Relatively good activity was observed although it was much less than that shown by similar palladium complexes. Similar O,N,S-bonded nickel complexes 26 derived from 9,10phenanthrenequinone thiosemicarbazone, 9,10-phenanthrenequinone N-methylthiosemicarbazone and 9,10-phenanthrenequinone N-phenylthiosemicarbazone have also been reported by Anitha et al, but these complexes gave only rather moderate results for Suzuki-Miyaura couplings [119]. Bidentate complexes 3 and 4 prepared and characterised by Paul et al, and described above in relation to their catalytic activity in the Heck reaction (Figure 1), were also examined for their possible use in the Suzuki-Miyaura reaction [95,102].…”

“…The octahedral nickel complexes 26 (Figure 4) prepared by Anitha et al derived from 9,10phenanthrenequinone thiosemicarbazone, 9,10-phenanthrenequinone N-methylthiosemicarbazone and 9,10-phenanthrenequinone N-phenylthiosemicarbazone described briefly above in connection with the Suzuki-Miyaura reaction were also examined for their activity in the Sonogashira reaction of phenyl acetylene with aryl halides [119]. Using catalyst loadings of 0.5 mol%, they were found to give good to very good conversions after 4 h in MeOH and in the presence of Cu(I) and pyridine (Scheme 27).…”

RETRACTED ARTICLE: Schiff base transition metal complexes for Suzuki–Miyaura cross-coupling reaction

“…3,4 Metal complexes containing Schiff base ligand have been studied for their interesting and important properties such as their ability to bind with oxygen, photochromism, antibacterial and antifungal properties, catalytic activity in olefins, hydrogenation and complexing proficieency towards a few toxic metals. 5,6 Transition metal-catalyzed cross-coupling reactions are undoubtedly the most utilized means for forming C-C, 7 C-N, 8 C-O, 9 and C-S 10 bonds in synthetic organic chemistry. Researchers are trying to develop simple, fast, cheap and more efficient methodologies for different coupling reactions.…”

Evaluation of DNA/BSA Binding and Chemical Nuclease Activity of L-Tyrosine-Based Mn(III) and Fe(III) Metallo-Intercalators

“…The signal for the methane carbon of L-tyrosine appears at δ 67.10. The signals in the range δ 114.12-136.16 are due to aromatic carbon 24 atoms of L-tyrosine as well as 9,10-phenanthrenequinone. The signal at δ 163.19 corresponds to the two azomethine carbons.…”