14052-12-1

Upstream product

• 100898-99-5 bis(μ-chloro)bis[1-3-η3-(1-chloromethyl)-1-buten-3-yl]dipalladium(II) 
• 110-86-1 pyridine 
• 40691-28-9 PdCl₂(P(C₆H₅)(2-C₆H₄Cl)2)2 
• 1121-60-4 pyridine-2-carbaldehyde 
• 7440-05-3 palladium 
• 59245-57-7 tetrapyridine palladium (II) tetrachloropalladate (II) 
• 935544-87-9 HCN(CH₂C(O)NHC₆H₅)CHCHN(CH₂C(O)NHC₆H₅)⁽¹⁺⁾*Cl^(1-)=(HCN(CH₂C(O)NHC₆H₅)CHCHN(CH₂C(O)NHC₆H₅))Cl 
• 13750-62-4 N-benzyl-2-methylimidazole 
• 78-95-5 chloroacetone 
• 78610-10-3 Pd₂Cl₄(As(C(CH₃)3)3)2 

Downstream Products

• 6894-19-5 bis(aniline)dichloridopalladium(II) 
• 13815-17-3 tetramminepalladium(II) chloride 
• 134625-37-9 PdCl₂(PPh₃)(py) 
• 54845-69-1 cis-[Pd(C₆F₅)2(py)2] 
• 632326-76-2 cis-[Pd(CH₂Ph)2(pyridine)2] 

Relevant academic research and scientific papers

Zwitterionic palladium complexes: Room-temperature Suzuki-Miyaura cross-coupling of sterically hindered substrates in an aqueous medium

A series of new imidazolium chlorides were straightforwardly prepared from the reactions between chloroacetone and imidazole derivatives. Deprotonation of the methylene proton next to the ketone group in these salts by pyridine led to the formation of a monodentate ligand that coordinated to palladium, readily forming zwitterionic anionic palladium pyridine complexes bearing a formal positive charge on the ligand ancillary. The pyridine ligand in the zwitterionic complexes can be facilely replaced by phosphine ligands. Seven of these new complexes were successfully characterized by X-ray crystallography. The zwitterionic phosphine complexes were highly efficient in catalyzing room-temperature Suzuki-Miyaura reactions between sterically hindered aryl chlorides and arylboronic acids in an aqueous medium.

Understanding existing and designing novel synthetic routes to Pd-PEPPSI-NHC and Pd-PEPPSI-PR3pre-catalysts

The reaction mechanism leading to the formation of cross-coupling palladium pre-catalysts of the PEPPSI family was investigated. Two intermediates were isolated and proved to be both suitable synthons to the pre-catalysts, with one permitting the design of a novel and greener user-friendly synthetic route. In light of this mechanistic understanding, the traditional one-pot method was shown to be possible using stoichiometric amounts of throw-away ligand, which represents a considerable synthetic improvement over the wasteful “in pyridine” approach.

Hydrolysis of methionine-containing peptides in binuclear and mononuclear palladium(II) complexes

The diaqua complexes of trans-[Pd(py)2Cl2] (Py-pyridine), cis-[Pd(edta)Cl2] (edta-ethylene diamine tetraacetic acid) (complex A), cis-[Pd(temed)Cl2] (temed-N,N,N′,N′-tetramethylethylene diamine) and cis-1,2-bis(2-formylglycinebenzenesulfenyl)ethane Pd(II) dichloride (complex C) react with methionine-containing dipeptides (AcMet-aa) (aa-amino acid) via the thioether group in the methionyl side chain. The trans-Pd(py)2(H2O)2]2+ and cis-[Pd(temed)(H2O)2]2+ yield binuclear complex [Pd2(μ-AcMet-aa)2(H2O)4] 4+, the diagua complexes of complex A and complex C yield mononuclear complexes, [PdL(AcMet-aa)(H2O)]2+ (L-edta, 1,2-bis(2-formylglycinebenzenesulfenyl)ethane). These reactions and hydrolytic cleavage of the Met-aa amide bond in the coordinated AcMet-aa are conveniently monitored by 1H NMR spectroscopy. The trans-Pd(py)2(H2O)2]2- is a very efficient promoter. The hydrolytic rate promoted by it is almost equal to that promoted by [Pd(H2O)3(OH)+, the fast one up to now. Although reaction of trans-[Pd(py)2(H2O)2)2+ and cis-[Pd(temed)(H2O)2]12+ with AcMet-aa yield the sam binuclear complex, [Pd2(μ-AcMet-aa)2(H2O)4] 4+, the kinetic data showed that the hydrolytic rate promoted by cis-[Pd(temed)(H2O)2]2+ was actually controlled by temed release. The new mononuclear complexes, [PdL(AcMet-aa)(H2O]2+, observed for the first time, are also hydrolytically active. It is of interest because they are closely associated with protein cleavage promoted by simple mononuclear Pd(II) complexes.

Nonchelate and chelate complexes of palladium(II) with N-heterocyclic carbene ligands of amido functionality

The imidazolium ligand precursors [L1H1H 2]Cl and [L2H12H2]C1 (H1 = NHC=O, H2 = NCHN) for the potentially bidentate and pincer-type amido-NHC ligands were synthesized in 66-78% yields. Selective deprotonation of H2 in these salts with pyridine in the presence of palladium chloride resulted in the monodentate palladium(II) complexes Pd(L 1H1)(py)Cl2 and Pd(L2H 12)(py)Cl2. The use of K2CO 3 in pyridine or DMF led to the double and triple deprotonations of the ligand precursors, giving the bis-bidentate and pincer-type palladium(II) complexes PdL12 and PdL2(py), respectively. Intriguingly, in certain cases, both the cis and the trans isomers of PdL 12 were formed and isolated in pure forms. A theoretical study indicates that the trans-PdL12 is thermodynamically more stable than the cis isomer (ca. 5.8 kcal mol-1). All the new complexes are characterized by NMR (ID and 2D) and single-crystal X-ray diffraction studies. A systematic study of the new complexes in Suzuki coupling reactions revealed the following order of activities: Pd(L1H 1)(py)Cl2 > PdL2(py) > PdL 12.

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 5. Synthesis, physicochemical and theoretical studies of a novel pentanuclear palladium(II) complex and related mononuclear species

New palladium(II) complexes of the free-base tetrakis[2,3-(5,6-di-2- pyridylpyrazino)porphyrazine], [Py8TPyZPzH2], have been prepared and their physicochemical properties examined. The investigated compounds are the pentanuclear species [(PdCl2)4Py 8TPyZPzPd], the monopalladated complex [Py8TPyzPzPd], and its corresponding octaiodide salt [(2-Mepy)8TPyzPzPd](I)8. All three PdII complexes have a common central pyrazinoporphyrazine core and differ only at the periphery of the macrocycle, where the simple dipyridinopyrazine fragments present in [Py8TPyzPzPd] bear four PdCl2 units coordinated at the pyridine N atoms in the pentanuclear complex, [(PdCl2)4Py8TPyzPzPd], or carry pyridine-N(CH3)+ moieties in the iodide of the octacation [(2-Mepy)8TPyzPzPd]8+. The structural features of the pentanuclear complex [(PdCl2)4Py8TPyZPzPd], partly supported by X-ray data and solution 1H NMR spectra of the [(CN)2Py2PyZPdCl2] precursor, were elucidated through one- and two-dimensional 1H NMR spectra in solution and density functional theory (DFT) calculations. Structural information on the monopalladated complex [Py8TPyZPzPd] was also obtained from DFT calculations. It was found that in the complex [(PdCl2) 4Py8TPyZPzPd] the peripheral PdCl2 units adopt a py-py coordination mode and the generated N2PdCl2 moieties are directed nearly perpendicular to the plane of the pyrazinoporphyrazine ring, strictly recalling the arrangement found for the palladated precursor [(CN)2Py2PyZPdCl2]. NMR and DFT results consistently indicate that of the four structural isomers predictable for [(PdCl2)4Py8TPyZPzPd], one having all four N2PdCl2 moieties pointing on the same side of the macrocyclic framework (i.e., isomer 4:0, plus the 3:1 and the 2:2-cis and 2:2-trans isomers), the 4:0 isomer (C4v symmetry) is the predominant form present. According to cyclic voltammetry and spectroelectrochemical results in pyridine, dimethyl sulfoxide (DMSO), and dimethylformamide (DMF), the monopalladated complex [Py8TPyZPzPd] undergoes four reversible or quasi-reversible one-electron ligand-centered reductions, similar to the behavior also observed for the pentanuclear complex [(PdCl2)4Py8TPyZPzPd], which shows an additional reduction peak attributable to the presence of PdCl2. Owing to the electron-withdrawing properties of the PdCl2 units, the pentanuclear complex is easier to reduce than the mononuclear complex [Py 8TPyzPzPd], some related [Py8TPyZPzM] complexes, and their porphyrin or porphyrazine analogues, so much so that the corresponding monoanion radical is generated at potentials close to 0.0 V vs SCE in DMSO or DMF. In turn, the monoanion of [(2-Mepy)8TPyzPzPd](I)8 is also extremely easy to generate electrochemically. Indeed, because of the eight positively charged N-CH3+ groups in this complex the first reduction occurs at potentials close to +0.10 V in DMSO or DMF. The redox behavior of the mono- and pentapalladated complexes has been rationalized on the basis of a detailed DFT analysis of their ground-state electronic structure.

Bis(CBT)palladium(II) Derivatives (CBT = m-carborane-1-thiolate): Synthesis, Molecular Structure, and Physicochemical Properties of cis-[(bipy)Pd(CBT)2] and trans-[(py)2Pd(CBT)2]

The new synthesized PdII complex cis-[(bipy)Pd(CBT)2] (bipy = 2,2′-bipyridyl; CBT = m-carborane-1-thiolate anion), which is a potential BNCT (boron neutron capture therapy) agent and of structure elucidated by single-crystal X-ray work, has been studied by infrared (IR) and ultraviolet-visible light (UV-vis) spectra and its properties compared with those of the previously reported and also the structurally characterized analogue trans-[(py)2Pd(CBT)2]. This trans species, prepared via a direct method, was previously isolated from a pyridine solution, consequent to the occurring releasing of the external Pd(CBT)2 moieties of the porphyrazine macrocycle [{Pd(CBT)2}4LZn]·xH2O (L = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato anion), which is an active photosensitizer in photodynamic therapy (PDT) and a potential bimodal PDT/BNCT agent. The UV-vis spectral behavior of both cis and trans species in CHCl3 solution and in the gas phase has been examined in detail by density functional theory (DFT) and time-dependent density functional theory (TDDFT) studies devoted to explain their distinct behavior observed in the region of 400-500 nm, as determined by the presence in the cis structure of a vicinal arrangement of the two CBT groups, an ensemble of results closely similar to those observed for the macrocycles [{Pd(CBT)2}4LM]·xH2O (M = MgII(H2O), ZnII, PdII). It has also been experimentally proved the tendency of the cis isomer in CHCl3/pyridine solution to be changed to the respective trans analogue, with conversion occurring in two steps, as interpreted by detailed DFT studies.

Syntheses and Structural Characterization of a Series of Hydrido Osmium-Palladium Carbonyl Clusters: n+4(μ-Cl)2-n> (n = 0-2), *H2O and *0.5C6H14

The unsaturated triosmium cluster reacted with the complex trans- (py = pyridine) to give a range of complexes including 1, 2, 3, 4, 5 and three known osmium clusters, , and .All five mixed-metal clusters were characterized by IR, 1H NMR and mass spectroscopy and X-ray crystallography.Complexes 1-3 have similar metal dispositions but different combinations of bridging hydrides and chlorides.They can be viewed as a diosmium fragment connected to the palladium vertex of the Os3Pd tetrahedron through a number of bridging ligands.Complex 4 is dimeric with two Os3Pd tetrahedra tied together by two bridging chlorides in a planar fashion.Complex 5 consists of an Os3Pd tetrahedron with a fourth osmium atom linked to the palladium vertex by three bridging chlorides.The pyridine ligand is co-ordinated to the singular osmium instead of the palladium atom.

Crystal structure, electronic properties and cytotoxic activity of palladium chloride complexes with monosubstituted pyridines

Palladium(ii) complexes attract great attention due to their remarkable catalytic and biological activity. In the present study X-ray characterization, UV-Vis and Time-Dependent Density Functional Theory (TD-DFT) calculations for six PdCl2(XPy)2 complexes (where: Py = pyridine; X = H, CH3 or Cl) were applied in order to investigate substituent effects on their crystal structures and electronic properties and to combine the results with their catalytic and cytotoxic activity. The structures of complexes PdCl2(3-MePy)2, PdCl2(4-MePy)2 and PdCl2(2-ClPy)2, have been described for the first time and we compared our results with available data for the whole series of six complexes. All compounds exhibit a square planar coordination geometry in which the palladium ion coordinates two nitrogen atoms of pyridine ligands and two chlorine atoms in trans positions. For complexes with ortho substituted XPy ligands a cis disposition of substituents takes place, whereas for other ligands: 3-MePy and 3-ClPy - the substituents are in trans positions. For XPy the energies of π-π* and n-π* transitions depend on the position and nature of the X substituent in the XPy ring. After complex formation a hipsochromic shift (24-34 nm) of π-π* and a bathochromic shift of n-π* bands are observed. The UV-Vis spectra of PdCl 2(XPy)2 confirm that square planar coordination geometry of complexes I-VI and two dπ-π* transitions are expected. With the help of the TD-DFT calculations we proved that dπ-π* transitions in solutions of PdCl2(XPy)2 complexes result from MLCT (metal-to-ligand charge transfer) with contribution from chlorine atoms to palladium. We also studied substituent effects on cytotoxic properties of Pd(ii) complexes against the human breast cancer cell line MCF7, the human prostate cancer cell line PC3, and the human T-cell lymphoblast-like cell line CCRF. The studied complexes were the most active against the CCRF cell line and less or even no cytotoxic effect was observed for PC3 cells. Complexes with MePy ligands showed increased cytotoxic activity compared to unsubstituted pyridine ligands.

Synthesis and characterization of novel PEPPSI type bicyclic (alkyl)(amino)carbene (BICAAC)-Pd complexes

A series of bicyclic alkylamino carbenes (BICAAC) (where N-aryl = dipp, mes, 2,6-dimethyl-4-(dimethylamino)phenyl, 5a–d) and their novel air- and moisture-resistant pyridine (pyridine, 4-dimethylaminopyridine) containing palladium Pd(II) complexes (6a–e) were synthetized and characterized. As novel examples of the PEPPSI (“pyridine enhanced precatalyst preparation stabilization and initiation”)-Pd compounds, the reported complexes have shown high activity in Mizoroki–Heck coupling reaction even at as low as 100 ppm loading (TON up to 10000). Kinetic studies revealed that reactions carried out in the presence of elemental mercury resulted decrease in activity. It indicates that the coupling reaction may have both molecular and Pd(0)-mediated catalytic paths.

An efficient Pd(II)-(2-aminonicotinaldehyde) complex as complementary catalyst for the Suzuki-Miyaura coupling in water

An efficient new Pd(II)-(2-aminonicotinaldehyde)-catalyzed Suzuki-Miyaura coupling of the aryl halides (Br, Cl and I) and organoboronic acids at moderate temperature in water is described. Low catalyst loading, easy accessibility, being an air-stable catalyst, functional group compatibility, and water as the reaction medium are some of the key features of this synthetic method. This protocol is also applicable for gram scale.