3402-70-8Relevant academic research and scientific papers
Thermally stable and robust gadolinium-based metal-organic framework: Synthesis, structure and heterogeneous catalytic O-arylation reaction
Ghosh, Pameli,Maity, Tanmoy,Biswas, Saptarshi,Debnath, Rakesh,Koner, Subratanath
, (2020/12/21)
Hydrothermal treatment of gadolinium nitrate and 2,6-naphthalenedicarboxylic acid (H2NDC) afforded a new metal-organic framework compound, {[Gd4(NDC)6(H2O)6]·2H2O}n(1). Compound 1 has been characterized by single-crystal X-ray crystallography, elemental analysis, FT-IR spectroscopy, therrmogravimetric analysis (TGA) and powder X-ray diffraction analysis. It is crystallized in the monoclinic system with the P21/n space group. Four crystallographically distinct Gd (III) centres are interconnected with each other through bridged carboxylato oxygen atoms and water molecules to form tetranuclear secondary building units, which are further connected through the carboxylato ligand and the network propagates along the crystallographic ac plane to form a 2D structure. Subsequent reinforcement from the remaining carboxylato oxygen atoms gives rise to a robust 3D framework structure. Thermogravimetric analysis demonstrates that compound 1 is fairly stable after dehydration under a nitrogen atmosphere. Notably, compound 1 is capable of catalyzing the O-arylation reaction efficiently between substituted phenols and bromoarene under heterogeneous conditions at 80 °C to afford unsymmetrical diarylethers.
Ligand-free copper-catalyzed O-arylation of arenesulfonamides with phenols: An unusual approach to biaryl ether synthesis
Chen, Junmin,Wang, Junmin,Chen, Xida,Huang, Yuming,Shouzhi, Pu
, p. 836 - 843 (2019/03/23)
An unprecedented ligand-free copper-catalyzed O-arylation of arenesulfonamides with phenols has been developed. Thus, a range of unsysmmetric biaryl ethers were synthesized in excellent yields. The reaction occurs efficiently with excellent regioselectivity through the cleavage of Cary–S bond and with a good tolerance of functional groups on the phenyl ring of phenols. The reaction is appreciated for its readily accessible substrates, mild conditions, and simple operation under air.
NOVEL TRIAZINE COMPOUND, AND ORGANIC ELECTRONIC ELEMENT AND PLANT-GROWING LIGHTING THAT USE THE SAME
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Paragraph 0081, (2018/07/28)
PROBLEM TO BE SOLVED: To provide a triazine compound which has a high triplet energy level and excellent heat resistance, and can be used as an organic electronic element material realizing an element with high efficiency, low voltage and a long life. SOLUTION: In the triazine compound, as represented by the general formula [1] in the figure, a triazine backbone moiety is linked to a dibenzofuran or dibenzothiophene backbone moiety via a biphenyl backbone moiety, where X is an oxygen atom or sulfur atom. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPO&INPIT
Immobilized palladium nanoparticles on MNPs@A-N-AEB as an efficient catalyst for C-O bond formation in water as a green Solvent
Moghaddam, Firouz Matloubi,Eslami, Mohammad
, (2018/08/24)
Palladium nanoparticles immobilized on the magnetic nanoparticles@2-amino-N-(2-aminoethyl) benzamide (MNPs@A-N-AEB.Pd0) have been presented as an efficient, and reusable magnetically heterogeneous catalyst for the C-O coupling reaction, namely Ullmann condensation reactions in an aqueous medium. This heterogeneous catalyst shows superior reactivity for the C-O arylation of different aryl halide (chloride, bromide, and iodide) with phenol derivatives to afford the desired products in good to excellent yields within short reaction time. Moreover, the catalyst can be easily recovered and reused for seven runs without loss of catalytic activity. The catalyst was characterized by several techniques, such as FT-IR, SEM, TEM, EDS, XRD, TGA and ICP-OES.
Synthesis of medium-sized (6-7-6) ring compounds by iron-catalyzed dehydrogenative C-H activation/annulation
Panda, Niranjan,Mattan, Irshad,Ojha, Subhadra,Purohit, Chandra Shekhar
supporting information, p. 7861 - 7870 (2018/11/21)
In this report, we have described a FeCl3-catalyzed process involving intramolecular annulation of o-phenoxy diarylacetylenes via hydroarylation to afford a series of biologically potent fused seven-membered (6-7-6) ring compounds under mild reaction conditions. This reaction was believed to proceed through Friedel-Crafts type sequential carbometallation followed by protonation to produce phenyldibenz[b,f]oxepines. This method was also extended to synthesize seven-membered rings that are fused with coumarins.
Access to Chiral Seven-Member Cyclic Amines via Rh-Catalyzed Asymmetric Hydrogenation
Li, Pan,Huang, Yi,Hu, Xinquan,Dong, Xiu-Qin,Zhang, Xumu
supporting information, p. 3855 - 3858 (2017/07/26)
A highly efficient asymmetric hydrogenation of azepine/oxazepine-type seven-member cyclic imine hydrochlorides was successfully developed using Rh/bisphosphine-thiourea ligand ZhaoPhos, affording various chiral seven-member cyclic amines with full conversions, high yields, and excellent enantioselectivities (up to 96% yield, >99% ee). Additionally, this asymmetric hydrogenation can proceed well on gram scale with excellent ee value. Moreover, control experimental results displayed that the anion-bonding interaction between the chloride ion of the substrate and thiourea motif of the ZhaoPhos played an important role to obtain excellent enantioselectivity.
Ullmann Coupling Reaction of Nitro-Substituted Aryl Halides with Phenols under Mild Conditions: Micro-/Mesoporous Hierarchical LaAlPO-5 Zeolite Catalyst
Ke, Qingping,Wu, Mingzhou,Wang, Chao,Lu, Guanzhong
, p. 1557 - 1563 (2016/05/02)
Heterogeneous catalytic reactions of aromatic organic molecules over zeolite catalysts present many challenges because of the shape selectivity of the micropores of conventional zeolites that limits the diffusion of aromatic molecules. Herein, Ullmann coupling reactions of phenols with nitro-substituted aryl halides were catalyzed by rare-earth-doped mesoporous AlPO-5 zeolites in the absence of ligands. The AlPO-5-MAlPO-5-M zeolites had a pure AFI structure and consisted of spherical particles assembled by nanofibers. The rare-earth elements were highly dispersed in the AlPO-5-MAlPO-5-M samples. The LaAlPO-5-MAlPO-5-M zeolite is an excellent catalyst for Ullmann coupling reactions of phenols and nitro-substituted aryl halides. Mesoporous LaAlPO-5 has an excellent stability and recyclability in the Ullmann coupling of p-X-nitrobenzene (X=Cl, Br, and I) with 2-naphthol. These results are important in the exploration of attractive Ullmann coupling reactions and in the development of mesoporous zeolite catalysts for other organic reactions.
Heterogeneous O -arylation of nitroarenes with substituted phenols over a copper immobilized mesoporous silica catalyst
Maity, Tanmoy,Bhunia, Susmita,Das, Soma,Koner, Subratanath
, p. 33380 - 33386 (2016/05/09)
Highly porous and robust mesoporous silica, SBA-15 has been subjected to post-synthesis modification for the anchoring of copper through Schiff base moiety formation using the silicon alkoxide route. The hybrid porous material has been fully characterized by powder-XRD, electronic spectra, EPR, thermogravimetric analysis, N2 sorption measurements, and TEM and SEM/EDS studies. The efficiency of the catalyst has been assessed in the O-arylation reaction using various substituted phenols and nitroarenes in heterogeneous conditions. The catalytic coupling reaction efficiently produces unsymmetrical diaryl ethers. The impressive capability to activate substrates having electron-donating or electron-withdrawing substituents and to have a high turnover frequency in the catalytic reactions made the catalyst highly desirable.
Four- and Sixfold Tandem-Domino Reactions Leading to Dimeric Tetrasubstituted Alkenes Suitable as Molecular Switches
Tietze, Lutz F.,Waldecker, Bernd,Ganapathy, Dhandapani,Eichhorst, Christoph,Lenzer, Thomas,Oum, Kawon,Reichmann, Sven O.,Stalke, Dietmar
, p. 10317 - 10323 (2015/09/01)
A highly efficient palladium-catalyzed fourfold tandem-domino reaction consisting of two carbopalladation and two C-H-activation steps was developed for the synthesis of two types of tetrasubstituted alkenes 3 and 6 with intrinsic helical chirality starting from substrates 1 and 4, respectively. A sixfold tandem-domino reaction was also developed by including a Sonogashira reaction. 20 compounds with different substitution patterns were prepared with yields of up to 97%. Structure elucidation by X-ray crystallography confirmed helical chirality of the two alkene moieties. Photophysical investigations of some of the compounds showed pronounced switching properties through light-controlled changes of their stereochemical configuration.
A family of ligand and anion dependent structurally diverse Cu(II) Schiff-base complexes and their catalytic efficacy in an O-arylation reaction in ethanolic media
Maity, Tanmoy,Saha, Debraj,Bhunia, Susmita,Brand?o, Paula,Das, Soma,Koner, Subratanath
, p. 82179 - 82191 (2015/10/12)
Two nitrato bridged dinuclear systems [Cu2(L1)2(NO3)3]NO3·H2O (1) and [Cu2(L2)2(NO3)3]NO3·MeOH (2), five monomeric complexes viz. [Cu(L3)(NO3)]NO3 (3), [Cu(L4)(NO3)]NO3 (4), [Cu(L5)(NO3)]NO3 (5), [Cu(L6)(NO3)NO3] (7), [Cu(L7)(NO3)]NO3 (8) and one hetero bi-bridged (phenoxido and water) dinuclear complex [Cu2(L2)2(H2O)2](ClO4)4·4H2O (6) have been synthesized and characterized using several physicochemical methods (L1 = 1-(N-3-methoxysalicylideneimino)-ethane-2-piperazine, L2 = 1-(N-3-ethoxysalicylideneimino)-ethane-2-piperazine, L3 = 1-(N-4′-ethoxy-α-methylasalicylideneimino)-ethane-2-piperazine, L4 = 1-(N-5′-chloro-α-methylasalicylideneimino)-ethane-2-piperazine, L5 = 1-(N-5-chlorosalicylideneimino)-ethane-2-piperazine, L6 = 1-(N-4-methoxysalicylideneimino)-ethane-2-piperazine and L7 = 1-(N-4′-methoxy-α-methylasalicylideneimino)-ethane-2-piperazine). X-ray structural analysis showed that complexes 1 and 2 are discrete dinuclear species where the pentacoordinated metal centers are bridged through a nitrate ion. In 3, 4, 5 and 8 the monomeric copper center displays a square pyramidal geometry with a weak axial Cu-O bond. In 7, the monomeric copper center shows a distorted octahedral geometry with two coordinated nitrate anions. However, in 6 the two copper centers coordinate in different manners (one is square-pyramidal and the other is distorted octahedral) and are bridged through a phenoxido group and a water molecule. All complexes efficiently catalyze the C-O coupling reaction under homogeneous conditions at 80 °C to afford unsymmetrical diaryl ethers using nitroarenes to act as an excellent electrophile. Notably, the reaction is carried out in ethanol media which facilitates the avoidance of toxic wastes. Structurally diverse copper(ii) Schiff-base complexes have rarely been used systematically in catalytic C-O coupling reactions.
