14592-56-4Relevant articles and documents
N, N′-Olefin functionalized Bis-Imidazolium Pd(II) chloride N-Heterocyclic carbene complex builds a supramolecular framework and shows catalytic efficacy for 'C-C' coupling reactions
Roymahapatra, Gourisankar,Samanta, Tapastaru,Seth, Saikat Kumar,Mahapatra, Ambikesh,Chattopadhyay, Shyamal Kumar,Dinda, Joydev
, p. 1057 - 1065 (2015)
The ligand 3,3′-(p-phenylenedimethylene)bis{1-(2-methylallyl)} imidazolium bromide (1) and its Palladium(II) N-heterocyclic carbene (NHC) complex (3) has been synthesized and characterized by several spectroscopic techniques and the solid-state structure of 3 has been determined by single crystal X-ray diffraction studies. The Pd(II) complex possesses ring head to tail π- π stacking interactions (3.767 A ) through imidazole rings. Complex 3 catalyzes Suzuki-Miyaura 'C-C' coupling reaction. DFT calculations have been used to understand the HOMO/LUMO energy and hence the stability and reactivity of Pd(II) complex in syn and anti-configuration.
Structure of Cu(II) and Pd(II) complexes with 2-(2,2-dimethylhydrazone)pentanone-4
Kuratieva,Vikulova,Shushanyan,Nikolaeva,Dorovskikh,Mikhaleva,Morozova
, p. 1004 - 1008 (2017)
Palladium(II) and copper(II) complexes with 2-(2,2-dimethylhydrazone) pentanone-4 are synthesized for the first time. The compounds are characterized by IR and NMR spectroscopy, elemental and single crystal X-ray diffraction analyses. The palladium complex crystallizes in the space group I41/a; the copper complex crystallizes in the space group P1?. Both compounds are molecular; the palladium chelate core has a distorted square geometry and that of copper has a distorted tetrahedral geometry. The average M–O and M–N bond lengths are respectively 1.9808(15) ? and 2.0427(17) ? for M = Pd, 1.915(8) ? and 1.97(1) ? for M = Cu. The chelate O–M–N angles are 88.32(7)-91.67(7)° for M = Pd, 93.37(4)-99.02(5)° for M = Cu.
Photolysis of tetraphenylcyclobutadiene palladium chloride induced by LMCT excitation
Kunkely, Horst,Vogler, Arnd
, p. 248 - 250 (2006)
The complex tetraphenylcyclobutadiene palladium(IV) chloride shows a longest-wavelength absorption at λmax = 530 nm which is assigned to a LMCT transition from the C4Ph4 dianion to Pd(IV). LMCT excitation leads to the release of Pd(CH3CN) 2Cl2 and neutral C4Ph4 which dimerizes to octaphenylcyclooctatetraene.
Flexible cofacial binuclear metal complexes derived from α,α-bis(salicylimino)-m-xylene
Maverick, Andrew W.,Laxman, Ravi K.,Hawkins, Mark A.,Martone, Daniel P.,Fronczek, Frank R.
, p. 200 - 206 (2005)
The tetradentate Schiff-base ligand SIXH2 (α,α-bis(salicylimino)-m-xylene), prepared from salicylaldehyde and m-xylylenediamine, forms cofacial binuclear complexes with Pd and Cu. Of the two isomers possible (trans-syn and trans-anti) for M2(SIX) 2, these complexes crystallize exclusively as the trans-anti isomer. In ansolvous Pd2(SIX)2, the metal-containing planes are approximately parallel, with Pd ... Pd 4.416(1) A. Pd 2(SIX)2 also forms a crystalline solvate, in which the molecules adopt a more open conformation with longer metal-metal distances (5.109(1) and 5.112(1) A). The M ... M distance is significantly longer in Cu2(SIX)2 (6.653(1) A), because of conformational changes in the m-xylylene moieties and substantial tetrahedral distortion about Cu.
Trimeric cage complexes of platinum group and coin metals
Stickel, Marc,Maichle-Moessmer, Caecilia,Mayer, Hermann A.
, p. 518 - 525 (2014)
The treatment of cis,cis-1,3,5-tris(diphenylphosphinomethyl)cyclohexane (tdppmcy) with Rh(CO)Cl(PPh3)2, MCl2L 2 (M = Pd, Pt; L = PhCN, MeCN), Pt(CN)2, AgBF4, or Au(Cl)PPh3 in a stoichiometric ratio of 2:3 affords the trimeric macrocyclic cage compounds [M]3(tdppmcy)2 {[M] = trans-Rh(CO)Cl (2), trans-PdCl2 (3), trans-Pt(CN)2 (4b), Ag+ (5), and AuCl (6)} in good yields. Only when PtCl 2(PhCN)2 was used as complex precursor, the formation of coordination polymers was observed. NMR spectroscopy in solution as well as single-crystal X-ray diffraction analyses demonstrate that in all cases two tdppmcy ligands coordinate three metal fragments exclusively in trans fashion. Copyright
A supramolecular recyclable catalyst for aqueous Suzuki-Miyaura coupling
Qi, Miao,Tan, Pei Zi,Xue, Fei,Malhi, Haripal Singh,Zhang, Zhong-Xing,Young, David J.,Hor, T. S. Andy
, p. 3590 - 3596 (2015)
A water-soluble, supramolecular catalytic system has been designed based on inclusion complexation between a hydrophobic palladium(ii)-dipyrazole complex bearing an adamantyl (Ad) molecular recognition moiety and a complementary, hydrophilic β-cyclodextrin (β-CD) derivative. The single-crystal molecular structure of the Pd(ii) complex was determined and its host-guest inclusion complexation with heptakis(2,6-di-O-methyl)-β-CD (dmβ-CD) in an aqueous medium was confirmed by 2D NOESY 1H NMR spectroscopy. The catalyst showed high activity for Suzuki-Miyaura coupling of hydrophilic aryl bromides with aryl boronic acids in aqueous organic solvents. In the presence of n-Bu4NBr as a stabilizer, the catalyst-containing reaction solution can be recycled and reused multiple times to catalyze the coupling reaction of fresh substrates once the product has been removed by centrifugation. This work demonstrates a supramolecular complex approach, non-covalently modifying a water insoluble metal complex to provide a water-soluble inclusion system to serve as a recyclable catalyst for potential application in green chemical synthesis. This journal is
Remarkable catalytic activity of [PdCl2(CH3CN) 2] in Suzuki-Miyaura cross-coupling reaction in aqueous media under mild conditions
Ganesamoorthy,Shanmugasundaram,Karvembu
, p. 118 - 124 (2013)
[PdCl2(CH3CN)2] (2 mol%) was found to be an efficient catalyst for the Suzuki-Miyaura cross coupling reaction between aryl bromide and aryl boronic acid in water solvent at 45 °C. The scope of the protocol was extended to various aryl bromides and aryl boronic acids. In general, an effective method has been developed for the Suzuki-Miyaura cross coupling reaction by using a phosphine-free Pd catalyst.
Palladium(II) complexes of 2-pyridylmethylamine and 8-aminoquinoline: A crystallographic and DFT study
Akerman, Kate J.,Venter, Chané,Hunter, Leigh A.,Akerman, Matthew P.
, p. 74 - 80 (2015)
Two nominally square planar palladium(II) chelates: dichloro-(2-aminomethylpyridine-N,N′)-palladium(II) ([Pd(L1)Cl2]) and dichloro-(8-aminoquinoline)-palladium(II) ([Pd(L2)Cl2]) have been synthesised and studied by X-ray crystallography and DFT methods. [Pd(L1)Cl2] crystallised in the monoclinic space group C2/c. In the solid state this compound exists as a one-dimensional supramolecular structure supported by N-HCl hydrogen bonds and metallophilic PdPd interactions. The same hydrogen bonding motif leads to a two-dimensional supramolecular structure in the case of [Pd(L2)Cl2]; this structure is devoid of metallophilic interactions. DFT simulations show that the planar geometry of [Pd(L1)Cl2] in the solid state is not the lowest energy conformation. An out-of-plane distortion of the methylene group leads to a structure ca. 11 kJ mol-1 lower in energy. The NBO partial charges provide insight into the stability of the hydrogen bonding motif. TD-DFT calculations were used to delineate the experimental UV-visible spectra.
Synthesis and redox chemistry of Pd(ii) complexes of a pincer verdazyl ligand
Sanz, Corey A.,Patrick, Brian O.,Hicks, Robin G.
, p. 12674 - 12683 (2019)
A series of palladium(ii) complexes containing a redox-active, tridentate verdazyl ligand of general formula (verdazyl)PdL (L = Cl, CH3CN) are synthesized. The tetrazine core of tridentate verdazyl ligand 5 is flanked by two pyridyl groups, creating a geometry in which the ancillary ligand L is bound trans to the verdazyl ring in the square planar metal complexes. Pd(ii) complexes were isolated with the verdazyl ligand in either its neutral radical charge state (6: L = CH3CN, 12: L = Cl) or its closed-shell monoanionic charge state (10: L = CH3CN, 9: L = Cl). The charge state of the ligand was determined using X-ray crystallography and NMR, EPR, and IR spectroscopy. The cyclic voltammograms of radical complexes 6 and 12 each contain a reversible one-electron reduction wave and an irreversible one-electron oxidation wave. The complexes can be chemically interconverted between radical ligand (6, 12) and reduced, closed-shell anion (9, 10) using decamethylferrocene as the reductant and a mixture of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and fluoroboric acid as the oxidant.
Silver(i), gold(i) and palladium(II) complexes of a NHC-pincer ligand with an aminotriazine core: A comparison with pyridyl analogues
Vaughan, Jamila,Carter, Damien J.,Rohl, Andrew L.,Ogden, Mark I.,Skelton, Brian W.,Simpson, Peter V.,Brown, David H.
, p. 1484 - 1495 (2016)
Dinuclear silver, di- and tetra-nuclear gold, and mononuclear palladium complexes with chelating C,N,C diethylaminotriazinyl-bridged bis(NHC) pincer ligands were prepared and characterised. The silver and gold complexes exist in a twisted, helical conformation in both the solution- and the solid state. In contrast, an analogous dinuclear gold complex with pyridyl-bridged NHCs exists in a linear conformation. Computational studies have been performed to rationalise the formation of twisted/helical vs. linear forms.
Nitrile-functionalized pyridinium ionic liquids: Synthesis, characterization, and their application in carbon-carbon coupling reactions
Zhao, Dongbin,Fei, Zhaofu,Geldbach, Tilmann J.,Scopelliti, Rosario,Dyson, Paul J.
, p. 15876 - 15882 (2004)
A series of relatively low-cost ionic liquids, based on the N-butyronitrile pyridinium cation [C3CNpy]+, designed to improve catalyst retention, have been prepared and evaluated in Suzuki and Stille coupling reactions. Depending on the nature of the anion, these salts react with palladium chloride to form [C3CNPy]2[PdCl4] when the anion is Cl- and complexes of the formula [PdCl 2(C3CNpy)2][anion]2 when the anion is PF6-, BF4-, or N(SO 2CF3)2-. The solid-state structures of [C3CNpy]Cl and [C3CNpy]2[PdCl4] have been established by single-crystal X-ray diffraction. The catalytic activity of these palladium complexes following immobilization in both N-butylpyridinium and nitrile-functionalized ionic liquids has been evaluated in Suzuki and Stille coupling reactions. All of the palladium complexes show good catalytic activity, but recycling and reuse is considerably superior in the nitrile-functionalized ionic liquid. Inductive coupled plasma spectroscopy reveals that the presence of the coordinating nitrile moiety in the ionic liquid leads to a significant decrease in palladium leaching relative to simple N-alkylpyridinium ionic liquids. Palladium nanoparticles have been identified as the active catalyst in the Stille reaction and were characterized using transmission electron microscopy.
Synthesis, characterization and biological investigation of glycine-based sulfonamide derivative and its complex: Vibration assignment, HOMO – LUMO analysis, MEP and molecular docking
Shafieyoon, Parvaneh,Mehdipour, Ebrahim,Mary, Y. Sheena
, p. 244 - 252 (2019)
A combined experimental and theoretical investigation has been reported on N-(glycine)-para styrene sulfonamide (abbreviated as GSS). The GSS and its complex were synthesized for first time in two steps. The GSS was synthesized from the reaction of para styrene sulfonyl chloride and glycine in the mild condition. The palladium complex was prepared from the reaction of PdCl2, CH3CN and GSS as a ligand. The GSS and its complex was confirmed using FT-IR and 1H-NMR spectra. The data obtained from wave number calculations are used to assign vibrational bands obtained in infrared and Raman spectra recorded. Potential energy distribution was done using GAR2PED program. HOMO-LUMO analysis, and Molecular Electrostatic Potential studies of the GSS and its complex have been investigated using DFT method. The GSS is investigated against Staphylococcus aureus and Escherichia coli. Molecular Docking study of GSS is also reported.
Carbazolyl-bis(triazole) and Carbazolyl-bis(tetrazole) Complexes of Palladium(II) and Platinum(II)
Samanta, Samya,Zheng, Cameron,Gajecki, Leah,Berg, David J.,Oliver, Allen G.,Crosby, Tristan,Godin, Logan,Sandhu, Jaylene
, p. 983 - 1008 (2021)
The synthesis of several carbazole-bis(triazole) (CzTrR) and carbazole-bis(tetrazole) (CzTR) ligands (5a–d and 6a–d, respectively, where R=Me (a), i–Pr (b), Bz (c) and CH2-2,4,6-C6H2Me3 (d)) is reported. Reaction of these ligands with PdCl2 in refluxing acetonitrile affords the complete series of square planar complexes, Pd(CzTrR)Cl (7a–d) and Pd(CzTR)Cl (8a–d). The analogous platinum complexes are prepared by deprotonation of ligand carbazole nitrogen under nitrogen followed by reaction with Pt(COD)Cl2 to give Pt(CzTrR)Cl (9b, 9d) and Pt(CzTR)Cl (10b, 10d). The X-ray structure of several ligands (5b, 5c, 6c) and their metal complexes (8b, 8d, 9b) are reported. Complexes 7–10d were examined by cyclic voltammetry and DFT calculations to shed light on their electronic structures. The Pd and Pt complexes of the same ligand (CzTr: 7d, 9d; CzT: 8d, 10d) showed very similar oxidation potentials suggesting the lowest oxidation is ligand based. In contrast, oxidations of the tetrazole complexes 7d and 9d were notably more difficult than the triazole complexes 8d and 10d. Both of these observations are supported by DFT calculations that indicate the HOMO is essentially carbazole π-bonding in character.
7-azaindol-1-yl(organo)silanes and their PdCl2 complexes: Pd-capped tetrahedral silicon coordination spheres and paddlewheels with a Pd-Si axis
Wahlicht, Sven,Brendler, Erica,Heine, Thomas,Zhechkov, Lyuben,Wagler, Joerg
, p. 2479 - 2488 (2014)
Supported by excess triethylamine, 7-azaindole (HL) and dichlorodimethylsilane (Me2SiCl2), methyltrichlorosilane (MeSiCl3), and tetrachlorosilane (SiCl4) react, respectively, with formation of the 7-azaindol-1-yl-substituted silanes Me 2SiL2, MeSiL3, and SiL4. In these compounds the silicon atom adopts [4+2], [4+3], and [4+4] coordination, respectively, with the pyridine N atoms of the 7-azaindol-1-yl groups capping the tetrahedral Si coordination sphere from distances of >3 A. Two pyridine nitrogen atoms of these silanes replace the acetonitrile ligands of [PdCl2(NCMe)2], thus forming the complexes Me 2Si(μ-L)2PdCl2, MeSiL(μ-L) 2PdCl2, and SiL2(μ-L)2PdCl 2. In addition to capping of the silicon coordination sphere by the pyridine N atoms of the dangling 7-azaindol-1-yl groups (in MeSiL(μ-L) 2PdCl2 and SiL2(μ-L)2PdCl 2), these three palladium complexes exhibit capping of one tetrahedral face of the Si coordination sphere by the palladium atom (with Si···Pd separations of 3.34, 3.43, and 3.31 A, respectively). According to computational analyses, the paddlewheel complex ClSi(μ-L)4PdCl should be energetically favored over its isomer SiL2(μ-L)2PdCl2; however, isomerization into this paddlewheel compound requires higher temperatures (150 °C) or the addition of a Lewis acid (such as GaCl3).
Development of an Efficient Synthesis of rac-3-Demethoxyerythratidinone via a Titanium(III) Catalyzed Imine-Nitrile Coupling
Luu, Hieu-Trinh,Streuff, Jan
, p. 139 - 149 (2019)
We herein describe the evolution of a rapid, high-yielding synthesis of the erythrina alkaloid 3-demethoxyerythratidinone. The natural product is assembled in six steps from commercial precursors in 30–35 % overall yield and with only two chromatographical purification operations. The key step is a titanium(III) catalyzed umpolung reaction in form of a reductive imine–nitrile coupling that can be combined with a subsequent cyclization reaction on a 50 mmol scale. Furthermore, optimized Wacker oxidation conditions enable the selective alkene oxidation in the presence of a tertiary amine functionality, which has been a problem in previous syntheses of erythrina alkaloids. The racemic route can be used to prepare the natural product on gram scale and the results may be useful for the synthesis of related alkaloids.
Excited state properties of dimeric π-allylpalladium(II) chloride. Photoreduction of palladium induced by ligand-to-metal charge transfer excitation
Kunkely, Horst,Vogler, Arnd
, p. 262 - 264 (2003)
The longest-wavelength absorption of [(π-allyl)PdIICl]2 at λmax=318 nm is assigned to an allyl-→PdII ligand-to-metal charge transfer (LMCT) transition. In the primary photochemical step LMCT excitation leads to the formation of an allyl radical and PdICl, which in acetonitrile undergoes a disproportionation to metallic palladium and palladium(II). PdII(CH3CN)2Cl2 is formed with φ=0.008 at λirr=366 nm.
Synthesis of Indoles by Reductive Cyclization of Nitro Compounds Using Formate Esters as CO Surrogates
Ahmed Fouad, Manar,Ferretti, Francesco,Formenti, Dario,Milani, Fabio,Ragaini, Fabio
supporting information, p. 4876 - 4894 (2021/09/20)
Alkyl and aryl formate esters were evaluated as CO sources in the Pd- and Pd/Ru-catalyzed reductive cyclization of 2-nitrostyrenes to give indoles. Whereas the use of alkyl formates requires the presence of a ruthenium catalyst such as Ru3(CO)12, the reaction with phenyl formate can be performed by using a Pd/phenanthroline complex alone. Phenyl formate was found to be the most effective CO source and the desired products were obtained in excellent yields, often higher than those previously reported using pressurized CO. The reaction tolerates many functional groups, including sensitive ones like a free aldehydic group or a pendant pyrrole. Detailed experiments and kinetic studies allow to conclude that the activation of phenyl formate is base-catalyzed and that the metal doesn't play a role in the decarbonylation step. The reactions can be performed in a single thick-walled glass tube with as little as 0.2 mol-% palladium catalyst and even on a 2 g scale. The same protocol can be extended to other nitro compounds, affording different heterocycles.
A ferrocene-templated Pd-bearing molecular reactor
Gunka, Piotr A.,Kasprzak, Artur
supporting information, p. 6974 - 6979 (2020/06/04)
High-yield, chromatography-free syntheses of a ferrocene-templated molecular cage and its Pd-bearing derivative are presented. The formation of a symmetric cage-type structure was confirmed by single-crystal X-ray diffraction analysis. The Pd-bearing cage was used as an innovative catalyst for the efficient synthesis of 1,1'-biphenyls under mild conditions. The presented catalyst is reusable and 1,1'-biphenyls can be obtained efficiently in a gram scale process.
