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Sanghamitra Das, Vasudevan Subramaniyan, Ganesan Mani
Unsymmetrical pincers have been shown to be better than the corresponding symmetrical pincers in several catalysis reactions. A new unsymmetrical PNN propincer, 2-(3,5-dimethylpyrazolylmethyl)-5-(diphenylphosphinomethyl)pyrrole (1), was synthesized from pyrrole through Mannich bases in a good yield. In addition, the new byproduct 2-(3,5-dimethylpyrazolylmethyl)-5-(dimethylaminomethyl)- N-(hydroxymethyl)pyrrole was also isolated. The reaction of 1 with [PdCl2 (PhCN)2 ] and Et3 N in toluene yielded [PdCl{C4 H2 N-2-(CH2 Me2 pz)-5-(CH2 PPh2 )-κ3 P,N,N}] (2)...
February 15, 2019: Inorganic Chemistry
Saki Komori, Yoshiko Yamaguchi, Yasutaka Kataoka, Yasuyuki Ura
Terminal acetals were selectively synthesized from various unbiased aliphatic terminal alkenes and 1,2-, 1,3-, or 1,4-diols using a PdCl2(MeCN)2/CuCl catalyst system in the presence of p-toluquinone under 1 atm of O2 and mild reaction conditions. The slow addition of terminal alkenes suppressed the isomerization to internal alkenes successfully. Electron-deficient cyclic alkenes, such as p-toluquinone, were key additives to enhance the catalytic activity and the anti-Markovnikov selectivity. The halogen groups in the alkenes were found to operate as directing groups, suppressing isomerization and increasing the selectivity efficiently...
January 21, 2019: Journal of Organic Chemistry
Wenling Jiao, Chen Chen, Wenbin You, Jie Zhang, Jiwei Liu, Renchao Che
A yolk-shell Fe/Fe4 N@Pd/C (FFPC) nanocomposite is synthesized successfully by two facile steps: interfacial polymerization and annealing treatment. The concentration of Pd2+ is the key factor for the density of Pd nanoparticles (Pd NPs) embedded in the carbon shells, which plays a role in the oxygen reduction reaction (ORR) and surface-enhanced Raman scattering (SERS) properties. The ORR and SERS performances of FFPC nanocomposites under different concentrations of PdCl2 are investigated. The optimal ORR performance exhibits that onset potential and tafel slope can reach 0...
January 16, 2019: Small
Mingyang Liu, Zhanrong Zhang, Xiaojun Shen, Huizhen Liu, Pei Zhang, Bingfeng Chen, Buxing Han
Stepwise degradation of hydroxyl compounds to aldehydes via successive cleavage of C-C bonds was achieved by using a bimetallic catalytic system (PdCl2 + CuCl) without any ligands and additives. The broad applicability is expanded to a diverse range of aromatic, aliphatic, primary and secondary alcohols, as well as lignin model compounds.
January 2, 2019: Chemical Communications: Chem Comm
Yanru Yin, Ning Ma, Jing Xue, Guoqiang Wang, Shuibo Liu, Hongliang Li, Peizhi Guo
Four types of palladium (Pd) nanoparticles were prepared from the systems containing PdCl2 or Na2PdCl4 with or without the assistance of polyvinylpyrrolidone (PVP). Two types of Pd nanoparticles obtained in the absence of PVP were obviously larger than those synthesized with the assistance of PVP. The former large Pd particles showed typical features in cycle voltammetry in H2SO4 solution, while two types of small Pd nanoparticles cannot. However, small nanoparticles treated firstly in electrochemical way in 0...
January 2, 2019: Langmuir: the ACS Journal of Surfaces and Colloids
Elisa Viola, Maria Pia Donzello, Silvia Testani, Giulia Luccisano, Maria Luisa Astolfi, Corrado Rizzoli, Lei Cong, Luisa Mannina, Claudio Ercolani, Karl M Kadish
New pentanuclear porphyrazine complexes of formula [{Pd(CBT)2 }4 LM]· xH2 O (L = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato anion, CBT = m-carborane-1-thiolate, and M = MgII (H2 O), ZnII , PdII ) were prepared in good yield as dark green hydrated amorphous solids by reaction of the respective pentanuclear species [(PdCl2 )4 LM] with m-carboran-1-thiol in CH3 CN. Physicochemical characterization of the new species was carried out by elemental and thermogravimetric analysis along with IR and 1 H/13 C NMR measurements...
December 31, 2018: Inorganic Chemistry
Xue Li, Yunyun Bian, Xin Chen, Hang Zhang, Wei Wang, Sida Ren, Xuechen Yang, Chang Lu, Chunxia Chen, Jinsong Peng
An efficient sequential one-pot synthesis of fused heterocycles based on 4-quinolinone and isoquinoline scaffolds of biological interest has been developed. In all cases, the first nucleophilic addition of 2-aryl quinolin-4(1H)-ones to alkynyl bromides in tert-pentyl alcohol can proceed in a chemo-, regio- and stereoselective manner to give (Z)-N-(1-bromo-1-alken-2-yl)quinolin-4-ones at 110 °C. Sequentially, these in situ functionalized adducts can undergo direct intramolecular aromatic C-H alkenylation in the presence of PdCl2 (5 mol%) in mixed solvents (tert-pentyl alcohol/DMF = 1 : 1), affording the novel quinolinone-fused isoquinoline derivatives in good yields...
December 13, 2018: Organic & Biomolecular Chemistry
Arián E Roa, Verónica Salazar, Daniel Mendoza-Espinosa, Margarita Paneque, Antonio Rodríguez-Diéguez, Ana M Rodríguez, Juan Tejeda, José A Castro-Osma, Antonio Otero, Agustín Lara-Sánchez
A new coordination mode for the hybrid scorpionate/cyclopentadienyl ligand bpzcp, [bpzcp = 2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethylcyclopentadienyl] is observed in iridium complexes. The reaction of the lithium precursor, [Li(bpzcp)(THF)], with a range of [IrCl(diene)]2 compounds leads to an unprecedented binding mode of the hybrid scorpionate/cyclopentadienyl ligand as η5 -Cp-coordinated and the formation of Ir(I) derivatives [Ir(η5 -Cp-bpzcp)(η4 -cod)] (1), [Ir(η5 -Cp-bpzcp){η4 -CH2 ═C(Me)C(Me)═CH2 }] (2), [Ir(η5 -Cp-bpzcp)(η2 -coe)2 ] (3), and [Ir(η5 -Cp-bpzcp)(η2 -CH2 ═CH2 )2 ] (4)...
December 12, 2018: Inorganic Chemistry
Lisbeth Rosholm Comstedt, Malin Engfeldt, Cecilia Svedman, Anna Åkesson, Monica Hindsén, Magnus Bruze
Concomitant reactions to palladium chloride (PdCl2 ), sodium tetrachloropalladate (Na2 PdCl4 ), and nickel hexahydrate sulphate (NiSO4 ·6H2 O) are very common during patch testing and have mainly been explained by cross-sensitisation. Whether there is variation in reactivity to palladium or covariation to nickel and palladium is not known. The aim of this study was to investigate the variation in patch test reactivity to PdCl2 and Na2 PdCl4 over time and compare this to variation in patch test reactivity to NiSO4 ·6H2 O...
October 1, 2018: European Journal of Dermatology: EJD
Mengdie Xu, Jing Zhao, Guiqing Shu, Xiu Zheng, Qi Liu, Yudong Wang, Minfeng Zeng
Novel porous nitrogen-doped carbon supported Pd (Pd@N-C) catalytic composites were prepared by one-pot thermal carbonization of chitosan/poly(ethylene glycol)‑block‑poly(propylene glycol)‑block‑poly(ethylene glycol)/PdCl2 (CS/P123/PdCl2 ) blend hydrogel membranes at different temperature in N2 atmosphere. The porous structure of the Pd@N-C catalytic composite was governed by both the addition of P123 and the carbonization temperature. At highest carbonization temperature of 900 °C, the prepared Pd@N-C catalytic composite from CS/P123/PdCl2 blend membrane showed the highest specific area (SBET ) of 293...
December 3, 2018: International Journal of Biological Macromolecules
Tsuyoshi Mita, Sho Ishii, Yuki Higuchi, Yoshihiro Sato
By using a new catalytic system (PdCl2 [P( n-Bu)3 ]2 in combination with ZnEt2 ), various 3-indolylmethanol derivatives were successfully carboxylated with CO2 (1 atm) via dearomatization of the indole nucleus, affording 3-methyleneindoline-2-carboxylates. In contrast, carboxylation of 2-indolylmethanol derivatives afforded unexpected doubly carboxylated products, which are useful synthetic precursors for biologically active compounds.
November 26, 2018: Organic Letters
John B Coulton, Aramis C Smith, Kraig A Wheeler, Radu F Semeniuc
A new ditopic ligand, N-(2,2-bis(pyrazolyl)ethyl)-2,2-bis(pyrazolyl)acetamide ((pz)2CH-C(O)-NH-CH2-CH(pz)2, L4Pz, pz = pyrazolyl ring), comprising two bis(pyrazolyl)methane donor groups linked via an amide bridge, has been prepared from the reaction of HOOCCH(pz)2 and H2NCH2CH(pz)2. The ligand coordinates to various metallic salts (i.e. AgO3SCF3, PdCl2, Re(CO)5Br, and Fe(BF4)2), in either a κ2-μ-κ2 or a κ3-μ-κ2 fashion, depending on the coordination preferences of the metallic center. These compounds were characterized by NMR, UV-Vis and IR spectroscopy, and in solid state by single crystal X-ray diffraction...
November 22, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Yaqian Zhao, Yunxing Li, Huan Pang, Cheng Yang, To Ngai
The combination of noble metal nanoparticles (NM NPs) and metal-organic frameworks (MOFs) for enhanced properties in catalysis is a rapidly developing interdisciplinary research field. Herein we report a facile one-step approach to the deposition of functional nanocomposite shell composed of NM NPs and conducting polymer on the surface of particulate UiO-66. Our approach is based on the recently developed double solvents method involving a hydrophobic solvent (n-hexane) and a hydrophilic solvent (water). Particularly, the n-hexane was used in a large amount to suspend the UiO-66 particles with hydrophilic inner pores and promoted the enrichment of the water containing the palladium chloride (PdCl2 ) inside the pores of UiO-66 particles, because these two solvents are immiscible and the volume of water is smaller than the pore volume of the UiO-66 particles...
November 10, 2018: Journal of Colloid and Interface Science
Riku Iwasaki, Eikichi Tanaka, Toshinari Ichihashi, Yasushi Idemoto, Kohei Endo
The treatment of PdCl2 with K2 CO3 and HCO2 H in dioxane gives black precipitates, which are an effective catalyst for the semireduction of alkynes to alkenes using formic acid as a reductant. Even 0.05 mol % Pd promoted the reduction reaction of tolane in high yield with high selectivity.
November 2, 2018: Journal of Organic Chemistry
Karel Škoch, Ivana Císařová, Filip Uhlík, Petr Štěpnička
Isomeric phosphinoferrocene ligands, viz. 1'-(diphenylphosphino)-1-cyanoferrocene (1) and 1'-(diphenylphosphino)-1-isocyanoferrocene (2), show markedly different coordination behaviours. For instance, the reactions of 1 with [PdCl2(MeCN)2] and [(LNC)Pd(μ-Cl)]2 (LNC = [2-(dimethylamino-κN)methyl]phenyl-κC1) produced the "phosphine" complexes [PdCl2(1-κP)2] (7) and [(LNC)PdCl(1-κP)] (8), and the latter was converted into the coordination polymer [(LNC)Pd(μ(P,N)-1)][SbF6] (9). Conversely, the reaction of 2 with [(LNC)Pd(μ-Cl)]2 involved coordination of the phosphine moiety and simultaneous insertion of the isocyanide group into the Pd-C bond, giving rise to the P,η1-imidoyl complex [PdCl(Ph2PfcN[double bond, length as m-dash]CC6H4CH2NMe2-κ3C,N,P)] (10; fc = ferrocene-1,1'-diyl)...
November 22, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Petre Flaviu Gostin, Owen Addison, Alexander P Morrell, Yue Zhang, Angus J M C Cook, Alethea Liens, Mihai Stoica, Konstantin Ignatyev, Steven R Street, Jing Wu, Yu-Lung Chiu, Alison J Davenport
Ti-based bulk metallic glasses are under consideration for implants due to their high yield strength and biocompatibility. In this work, in situ synchrotron X-ray diffraction (XRD) is used to investigate the corrosion products formed from corrosion of Ti40 Zr10 Cu34 Pd14 Sn2 bulk metallic glass in artificial corrosion pits in physiological saline (NaCl). It is found that Pd nanoparticles form in the interior of the pits during electrochemical dissolution. At a low pit growth potential, the change in lattice parameter of the Pd nanoparticles is consistent with the formation of palladium hydride...
September 16, 2018: Advanced Healthcare Materials
Sadeeq Ullah, Aftab Ahmad, Arifullah Khan, Jie Zhang, Muslim Raza, Aziz Ur Rahman, Muhammad Tariq, Usman Ali Khan, Shah Zada, Qipeng Yuan
Low cost and an easy technique for the synthesis of palladium nanoparticles (PdNPs) was developed. Glucosamine was used to stabilize palladium precursor (PdCl2 ) into palladium nanoparticles. Several analytical techniques were used for the determination of morphology, crystalline structure; size, capping, and composition of synthesize palladium nanoparticles. The UV-visible spectroscopy SPR peak (Surface Plasmon Resonance) at 284 nm revealed synthesis of PdNPs. Energy dispersive X-ray (EDX) and X-ray diffraction (XRD) studies proved the elemental composition and crystalline structure of the synthesized palladium nanoparticles respectively...
September 12, 2018: Microbial Pathogenesis
Yasunari Monguchi, Tomohiro Ichikawa, Tsuyoshi Yamada, Yoshinari Sawama, Hironao Sajiki
Microwave-assisted continuous-flow reactions have attracted significant interest from synthetic organic chemists, especially process chemists from practical points of view, due to a less complicated shift to large-scale synthesis based on simple and continuous access to products with low energy requirements. In this personal account, we focused on the Suzuki-Miyaura and Mizoroki-Heck reactions, both of which are significantly important cross-coupling reactions for the synthesis of various functional materials...
September 4, 2018: Chemical Record: An Official Publication of the Chemical Society of Japan ... [et Al.]
Tao Zhang, Guigang Deng, Hanjie Li, Bingxin Liu, Qitao Tan, Bin Xu
A palladium-catalyzed synthesis of dibenzothiophenes from 2-biphenylthiols is described. This highly efficient reaction employs a simple PdCl2 /DMSO catalytic system, in which PdCl2 is the sole metal catalyst and DMSO functions as an oxidant and solvent. This transformation has broad substrate scope and operational simplicity and proceeds in high yield. The synthetic utility was demonstrated by the facile synthesis of helical dinapthothiophene 3 and an eminent organic semiconductor DBTDT 4. Importantly, highly strained trithiasumanene 5, a buckybowl of considerable synthetic challenge, was observed under this catalytic system...
September 7, 2018: Organic Letters
Rena Simayi, Simone M Gillbard, Warren B Cross, Eric G Hope, Kuldip Singh, Gregory A Solan
The pyridylimine-substituted 1-naphthalenes, 2-(1-C10H7)-6-{CR[double bond, length as m-dash]N(2,6-i-Pr2C6H3)}C5H3N (R = Me HLMe, H HLH), react with Na2[PdCl4] in acetic acid at elevated temperature to afford either ortho-C-Hnaphthyl activated (LMe)PdCl (2ortho) or the unactivated adduct (HLH)PdCl2 (1b). Alternatively, 1b and its ketimine analogue (HLMe)PdCl2 (1a), can be prepared by treating (MeCN)2PdCl2 with either HLMe or HLH in chloroform at room temperature. Regio-selective ortho-C-H activation to form 2ortho can also be initiated by the thermolysis of 1a in acetic acid, while no reaction occurs under similar conditions with 1b...
August 21, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
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