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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...
August 14, 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 13, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Vnira Rakhimovna Akhmetova, Rozalia Akramovna Galimova, Nail Salavatovich Akhmadiev, Albina Midkhatovna Galimova, Ravil Akhmetzyanovich Khisamutdinov, Galiya Maratovna Nurtdinova, Eduard Feliksovich Agletdinov, Valery Alekseevich Kataev
Purpose: This research is devoted to designing the synthesis of sulfanyl-substituted 3,5-dimethylisoxazoles, which contain structural analogues of the SAM drug in the molecule. SAM (S-adenosyl-L-methionine), formed in the biosynthetic process, is used as an effective hepatoprotective drug. Complexation and hepatoprotective properties of the combinatorial series of bis(isoxazolylsulfanyl)ethane have been studied. Methods: Bis(isoxazol-4-ylmethylsulfanyl)alkanes were synthesized using the one-pot method. The structures of compounds were established by one-dimensional (1 H,13 C) and two-dimensional (COSY, HCQS, HMBC) NMR spectroscopy, mass-spectrometry and X-ray diffraction...
June 2018: Advanced Pharmaceutical Bulletin
Sheng Zhang, Hengmin Ma, Hon Eong Ho, Yoshinori Yamamoto, Ming Bao, Tienan Jin
A new and efficient Pd-catalyzed cascade cyclization of biaryl-tethered o-alkynylanilines for the formation of dibenzo[a,c]carbazole derivatives has been reported. The use of the alkyl-substituted tertiary anilines together with the combination of the PdCl2 catalyst with the MnO2 oxidant and PivOH is vital for giving rise to 5-endo cyclization, C-N bond cleavage, and C-H bond activation in a cascade manner to produce the corresponding products with structural diversity.
July 25, 2018: Organic & Biomolecular Chemistry
Sunit Kumar, Kishor G Thorat, Way-Zen Lee, Mangalampalli Ravikanth
A new nonaromatic selenabenziporphyrin was synthesized by (3 + 1) condensation of m-benzitripyrrane and 2,5-bis[( p-tolyl)hydroxymethyl] selenophene under mild trifluoroacetic acid-catalyzed reaction conditions. The selenabenziporphyrin was characterized by high-resolution mass spectrometry, one- and two-dimensional NMR spectroscopy, and X-ray crystallography. The crystal structure revealed that the macrocycle was planar with moderately tilted m-phenylene ring and that the phenylene ring completely blocks the macrocyclic π-delocalization...
July 9, 2018: Inorganic Chemistry
Oishi Jana, Ganesan Mani
2,6-Bis(3,5-dimethylpyrazoylmethyl)-4-methylphenol LH was readily synthesized by the reaction between 2,6-bis[(dimethylamino)methyl]-4-methylphenol and 3,5-dimethylpyrazole. The X-ray structure of the trisodium complex of LH showed the benzene-like planar Na3 O3 ring with alternative shorter (2.181-2.185 Å) and longer (2.244-2.263 Å) bonds. The reaction of anionic ligand L with [PdCl2 (COD)] yielded three Pd(II) complexes: [Pd{OC6 H2 (CH2 PzMe2 )2 -2,6-Me-4-κ N, O}2 ] (1), [PdCl{μ-OC6 H2 (CH2 PzMe2 )2 -2,6-Me-4-κ N, O, N}]2 (2), and [PdCl2 {μ-OC6 H2 (CH2 PzMe2 )2 -2,6-Me-4-κ N, O, N}2 Pd] (3) (PzMe2 = 3,5-dimethylpyrazole)...
July 2, 2018: Inorganic Chemistry
Ioannis Bratsos, Christos Tampaxis, Ioannis Spanopoulos, Nicola Demitri, Georgia Charalambopoulou, Dionisios Vourloumis, Theodore A Steriotis, Pantelis N Trikalitis
The targeted synthesis of metal-organic frameworks (MOFs) with open metal sites, following reticular chemistry rules, provides a straightforward methodology toward the development of advanced porous materials especially for gas storage/separation applications. Using a palladated tetracarboxylate metalloligand as a 4-connected node, we succeeded in synthesizing the first heterobimetallic In(III)/Pd(II)-based MOF with square-octahedron (soc) topology. The new MOF, formulated as [In3 O(L)1.5 (H2 O)2 Cl]·n(solv) (1), features the oxo-centered trinuclear clusters, [In3 (μ3 -O)(-COO)6 ], acting as trigonal-prismatic 6-connected nodes that linked together with the metalloligand trans-[PdCl2 (PDC)2 ] (L4- ) (PDC: pyridine-3,5-dicarboxylate) to form a 3D network...
June 18, 2018: Inorganic Chemistry
Pengfei Ai, Kirill Yu Monakhov, Jan van Leusen, Paul Kögerler, Christophe Gourlaouen, Moniek Tromp, Richard Welter, Andreas A Danopoulos, Pierre Braunstein
Selective copper(I) to palladium(0) transmetallation of P-donors from the rigid N,N'-diphosphanyl-imidazol-2-ylidene C3 H2 [NP(tBu)2 ]2 (PCNHC P) was observed when known [Cu3 (μ3 -PCNHC P,κP,κCNHC ,κP)2 ](OTf)3 was reacted with [Pd(PPh3 )4 ]. When 1.2 equivalents of [Pd(PPh3 )4 ] was used, the product [Cu2 Pd(μ3 -PCNHC P,κP,κCNHC ,κP)2 ](OTf)2 (2(OTf)2 ) was obtained, which features a CuI -CuI -Pd0 chain and appears to be the first linear heterotrinuclear complex with d10 -d10 interactions between Pd0 and CuI ...
June 21, 2018: Chemistry: a European Journal
Madhusudan K Pandey, Joel T Mague, Maravanji S Balakrishna
The synthesis of sterically demanding aminophosphine and phosphinite ligands Ar*NHPPh2 (1) and Ar*OPPh2 (2), based on 2,6-dibenzhydryl-4-methylphenyl core having bulky benzhydryl groups, and their RuII , PdII and PtII complexes is described. The reactions of 1 and 2 with [Ru(η6 - p-cymene)Cl2 ]2 in 2:1 molar ratios produced mononuclear complexes [RuCl2 {(η6 - p-cymene)PPh2 -EAr*}-κ1 -P] (E = NH (3) and O (4)). Interestingly, complexes 3 and 4, upon refluxing in chlorobenzene, displace the p-cymene ring by one of the phenyl rings of side arms, forming rare η6 -arene coordinated tethered complexes [RuCl2 {(PPh2 -EAr*)-κ1 -P-η6 -arene}] (E = NH (5) and O (6))...
June 18, 2018: Inorganic Chemistry
Austin Bonnette, Joel T Mague, Perumalreddy Chandrasekaran
A palladium(II) complex {systematic name: dichlorido[1,3-di- tert -butyl-2,4-bis( tert -butylamino)-1,3,2λ5 ,4λ5 -diazadiphosphetidine-2,4-diselone-κ2 Se , Se ']pal-ladium(II)}, cis -[PdCl2 { I }], ( II ), containing a bis-(selenium) ligand based on cyclo-diphosph(V)azane, cis -[( t BuNH)(Se)P(μ-N t Bu)2 P(Se)(NH t Bu)], ( I ), has been synthesized and structurally characterized. The crystal structure of complex II reveals that the ligand chelates through selenium donors with the natural bite-angle of 110...
February 1, 2018: Acta Crystallographica. Section E, Crystallographic Communications
Alexander G R Howe, Peter J Miedziak, David J Morgan, Qian He, Peter Strasser, Jennifer K Edwards
A series of 1 wt% supported Au, Pd and AuPd nanoalloy catalysts were prepared via microwave assisted reduction of PdCl2 and HAuCl4 in a facile, one pot process. The resulting materials showed excellent activity for the direct synthesis of hydrogen peroxide from hydrogen and oxygen, with a synergistic effect observed on the addition of Au into a Pd catalyst. Detailed electron microscopy showed that the bimetallic particles exhibited a core-shell morphology, with an Au core surrounded by an Au-Pd shell, with a size between 10-20 nm...
May 25, 2018: Faraday Discussions
Alexander S Mikherdov, Mikhail A Kinzhalov, Alexander S Novikov, Vadim P Boyarskiy, Irina A Boyarskaya, Margarita S Avdontceva, Vadim Yu Kukushkin
The reaction of cis-[PdCl2 (CNXyl)2 ] (Xyl = 2,6-Me2 C6 H3 ) with the aminoazoles [1 H-imidazol-2-amine (1), 4 H-1,2,4-triazol-3-amine (2), 1 H-tetrazol-5-amine (3), 1 H-benzimidazol-2-amine (4), 1-alkyl-1 H-benzimidazol-2-amines, where alkyl = Me (5), Et (6)] in a 2:1 ratio in the presence of a base in CHCl3 at RT proceeds regioselectively and leads to the binuclear diaminocarbene complexes [(ClPdCNXyl)2 {μ-C(N-azolyl)N(Xyl)C═NXyl}] (7-12; 73-91%). Compounds 7-12 were characterized by C, H, N elemental analyses, high-resolution ESI+ -MS, Fourier transform infrared spectroscopy, 1D (1 H, 13 C) and 2D (1 H,1 H-COSY, 1 H,1 H-NOESY, 1 H,13 C-HSQC, 1 H,13 C-HMBC) NMR spectroscopies, and X-ray diffraction (XRDn)...
June 4, 2018: Inorganic Chemistry
Magdalena Staniszewska, Stephan Kupfer, Julien Guthmuller
Time-dependent density functional theory calculations combined with the Marcus theory of electron transfer (ET) were applied on the molecular photocatalyst [(tbbpy)2 Ru(tpphz)PdCl2 ]2+ in order to elucidate the light-induced relaxation pathways populated upon excitation in the longer wavelength range of its absorption spectrum. The computational results show that after the initial excitation, metal (Ru) to ligand (tpphz) charge transfer (MLCT) triplet states are energetically accessible, but that an ET toward the catalytic center (PdCl2 ) from these states is a slow process, with estimated time constants above 1 ns...
May 16, 2018: Chemistry: a European Journal
Christian W Lopes, Jose L Cerrillo, Antonio E Palomares, Fernando Rey, Giovanni Agostini
The activation of precursor-dependent Pd nanoparticles was comprehensively followed by in situ X-ray absorption spectroscopy on two inorganic supports for rationalizing the final catalytic activity. Two series of Pd-based catalysts (7 wt% Pd) were prepared by impregnation of γ-Al2O3 and activated carbon supports varying the metal precursor (Pd(NO3)2, PdCl2 and Pd(OAc)2). The most relevant physicochemical properties of the studied catalysts were determined by several techniques including ICP-OES, XRD, N2 adsorption and XAS...
May 9, 2018: Physical Chemistry Chemical Physics: PCCP
Mi Yeon Byun, Ji Sun Kim, Dae-Won Park, Man Sig Lee
The increasing role of catalysis by noble metals coupled with their high price requires the development of cheaper and more effective catalysts, e.g., highly dispersed supported catalyst. Herein, Pd supported on Al2O3 catalysts prepared by deposition-precipitation under different conditions were subjected to X-ray diffraction, N2-physisorption, NH3/CO2 temperature programmed desorption, CO-chemisorption, and field-emission transmission electron microscopy analyses, which revealed that the size and distribution of Pd particles were influenced by Al2O3 support type (particle size and phase transition) and preparation conditions (metal precursor type, pH value, and solution temperature)...
September 1, 2018: Journal of Nanoscience and Nanotechnology
Yongyi Wei, Zhan Mao, Zhenzhong Li, Fang Zhang, Hexing Li
Heterogeneous organometallic catalysts with well-defined active sites and hierarchical pores hold tremendous promise for efficient and eco-friendly chemical processes. However, the simple and scalable preparation of these materials remains difficult to date, which has hampered a more broad application scope. Herein, we reported a low-cost, rapid, and scalable aerosol-assisted assembly approach for the synthesis of a well-defined PdDPP (PdCl2 (PPh2 (CH2 )2 ))_ complex-containing benzene-bridged organosilica-based catalyst with a hierarchical bimodal micro-macroporous structure...
April 25, 2018: ACS Applied Materials & Interfaces
Albert Gallen, Sílvia Orgué, Guillermo Muller, Eduardo C Escudero-Adán, Antoni Riera, Xavier Verdaguer, Arnald Grabulosa
Both enantiomers of the optically pure Secondary Phosphine Oxide (SPO) t-BuMeP(O)H (1) have been obtained by deboronation of phosphinous acid-borane t-BuMeP(O)H·BH3 (3) with HBF4 followed by hydrolysis of the intermediate adduct t-BuMeP(O)H·BF3 (1·BF3), which has been isolated and crystallographically characterised. Complexes [MCl(COD)(κP-(R)-1)] (M = Ir, Rh; 4 and 7 respectively) have been detected in solution but could not be isolated while trans-[RhCl(CO)(κP-(S)-1)2] (9) has been successfully obtained in good yield...
April 17, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Alexander S Mikherdov, Alexander S Novikov, Mikhail A Kinzhalov, Vadim P Boyarskiy, Galina L Starova, Alexander Yu Ivanov, Vadim Yu Kukushkin
The reaction of cis-[PdCl2 (CNCy)2 ] (1) with thiazol-2-amines (2-10) leads to the C,N-chelated diaminocarbene-like complexes [PdCl{ C(N(H)4,5-R2 -thiazol-2-yl)NHCy}(CNCy)] (11-14; 82-91%) in the case of 4,5-R2 -thiazol-2-amines (R, R = H, H (2), Me, Me (3), -(CH2 )4 - (4)) and benzothiazol-2-amine (5) or gives the diaminocarbene species cis-[PdCl2 {C(N(H)Cy)N(H)4-R-thiazol-2-yl}(CNCy)] (15-19; 73-93%) for the reaction with 4-aryl-substituted thiazol-2-amines (R = Ph (6), 4-MeC6 H4 (7), 4-FC6 H4 (8), 4-ClC6 H4 (9), 3,4-F2 C6 H3 (10))...
March 19, 2018: Inorganic Chemistry
Astrid M Olivares, Daniel J Weix
The synthesis of highly substituted 1,3-dienes from the coupling of vinyl bromides with vinyl triflates is reported for the first time. The coupling is catalyzed by a combination of (5,5'-bis(trifluoromethyl)-2,2'-bipyridine)NiBr2 and (1,3-bis(diphenylphosphino)propane)PdCl2 in the presence of a zinc reductant. This method affords tetra- and penta-substituted 1,3-dienes that would otherwise be difficult to access and tolerates electron-rich and -poor substituents, heterocycles, an aryl bromide, and a pinacol boronate ester...
February 21, 2018: Journal of the American Chemical Society
Lei Wang, Mingjie Chen, Peichao Zhang, Wenbo Li, Junliang Zhang
Herein we reported an efficient palladium-catalyzed enantioselective arylation of both alkyl and aryl sulfenate anions to deliver various chiral sulfoxides in good yields (up to 98%) with excellent enantioselectivities (up to 99% ee) by the use of our developed chiral O,P-ligands (PC-Phos). PC-Phos are easily prepared in short steps from inexpensive commercially available starting materials. The single-crystal structure of the PC4/PdCl2 showed that a rarely observed 11-membered ring was formed via the O,P-coordination with the palladium(II) center...
March 7, 2018: Journal of the American Chemical Society
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