A group of diphosphine-thiosemicarbazone complexes of palladium: Efficient precursors for catalytic C C and C N coupling reactions

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

“…Cationic complexes 23 of the type [Pd(dppe)L]NO3 (dppe = 1,2-bis(diphenylphosphino)ethane), where L is a bidentate thiosemicarbazone ligand derived from a p-substituted benzaldehyde were prepared by Thapa et al, and structurally characterised, confirming the formation of N,S-chelated 5membered rings (Figure 4) [117]. The authors hypothesised that, in view of the previously observed Dharani et al reported a series of palladium complexes 22 derived from 3-acetyl-7-methoxy-2H-chromen-2-one thiosemicarbazones (Figure 3) [115].…”

“…It was found that the catalyst could be used twice without any detectable loss of activity but that gradual loss of activity was observed for subsequent cycles. Apart from the aforementioned monophosphine complexes, a recent study reports the synthesis of a cationic Pd thiosemicarbazone complex 23 (R = OCH 3 ; see in Figure 4) containing a diphosphine which, apart from catalysing the Suzuki-Miyaura reaction (see above) was also found to be effective in the Buchwald-Hartwig arylation [117]. Aryl bromides and iodides gave good conversions in the reaction with primary or secondary amines in either dioxane at 100 • C or PEG at 150 • C with low catalyst loadings (0.01 mol%) in the presence of NaOBu t .…”

Molecular Organosulphur, Organoselenium and Organotellurium Complexes as Homogeneous Transition Metal Catalytic Systems for Suzuki Coupling

“…These ligands have been used in the development of homogeneous catalytic systems [18–102] . All such ligands behave as Lewis bases due to the presence of chalcogen (S/Se/Te) donor sites, and form a coordinate (i. e. dative) bond with the metal through such sites.…”

“…Such systems include preformed complexes of metals with a variety of ligands [10,11,14,15,17] in molecular form (i. e., homogeneous catalysts). All these types of systems have also been designed using organosulphur, organoselenium and organotellurium ligands [10,11,18–86] during last decade. The chalcogen donor containing systems are very popular due to their high efficiency and stability.…”

[1,2-Bis(diphenylphosphanyl)ethane-κ2 P,P]chlorido(isonicotinamide-κN)palladium(II) nitrate acetonitrile monosolvate

“…Palladium complexes containing 1,2-bis(diphenylphosphanyl)ethane as a ligand have received much attention over the last decade because of their application in catalysis (Naghipour et al, 2021;Thapa et al, 2019). Recently, some of the focus has shifted to exploring their cytotoxicity (Cullinane et al, 2018;Kuijpers & Blom, 2021) and biological activity (Al-Janabi et al, 2021).…”