Synthesis and properties of 7,7-bis(heteroazulen-3-yl)-8,8-dicyano-1,4-quinodimethanes

The synthesis and properties of a novel type of 7,7-bis(heteroazulen-3-yl)-8,8-dicyano-1,4-quinodimethanes (9a-c) are studied. The synthetic method is based on a TFA-catalyzed electrophilic aromatic substitution on the heteroazulenes with 4-(dicyanomethyl)benzaldehyde to afford the corresponding methane derivatives, followed by oxidative hydrogen abstraction with DDQ. The polarization of 9a-c is evaluated by the inspection of their ¹³C NMR and IR spectra. Based on the investigation of the UV-Vis spectra of 9a-c and protonated cations 10a-c, conformational changes of the heteroazulene-moiety and (dicyanomethyl)phenyl group are suggested. In the CV measurements of 9a-c, two reversible reduction waves are observed, indicating the stabilizing ability of heteroazulenes toward the corresponding radical and anion species. Furthermore, 9a-c exhibit two irreversible oxidation waves, which suggest a conformational change in the radical cation during the redox process. The conformational change is rationalized on the basis of the MO calculations.     

Eu(NTf2)3催化吲哚与醛(酮)反应合成二吲哚基甲烷

二(三氟甲基磺酰)亚胺铕(III) [Eu(NTf₂)₃, Tf＝SO₂CF₃]作催化剂, 吲哚与醛(酮)在室温下发生亲电取代反应合成了一系列二吲哚基甲烷, 产率85%～98%. 该法反应条件温和、时间短、催化剂用量少且可以回收重复使用.     

Synthesis and properties of 5-[bis(1-heteroazulen-3-yl)methylidene]pyrimidine-2,4,6(1,3,5H)-triones

The synthesis and properties of a novel type of 5-[bis(1-heteroazulen-3-yl)methylidene]pyrimidine-2,4,6(1,3,5H)-triones (13a-c) and (14a-c) are studied. The synthetic procedure is based on addition of bis(1-heteroazulen-3-yl)methyl cations with barbituric acid and subsequent oxidation by o-chloranil. Structural characteristics of 13a-c and 14a-c were clarified on inspection of the ¹³C NMR spectral data and X-ray crystal analysis. Based on the investigation of the UV-vis spectra of 13a-c and 14a-c and their protonated cations, conformational change of the heteroazulene-moiety and the barbituric acid-moiety is suggested. In the CV measurements of 13a-c and 14a-c, two reversible reduction waves are observed, indicating the stabilizing ability of heteroazulenes toward the corresponding radical and anion species. Furthermore, 13a-c and 14a-c exhibit one irreversible oxidation wave and the corresponding reduction wave appearing in a far negative region, which suggested a conformational change in the radical cation during the redox process. The conformational change is rationalized on the basis of the MO calculations.     

Synthesis,spectral and electrochemical properties of mixed-ligand ruthenium(II) complexes of bis(pyrid-2-yl)- and bis(benzimidazol-2-yl)-dithioether ligands: Effect of an asymmetric diimine co-ligand

Two new mixed-ligand Ru(II) complexes [Ru(pdto)(dppt)](ClO₄)₂ (1) and [Ru(bbdo)(dppt)](ClO₄)₂ (2), where pdto = 1,8-bis(pyrid-2-yl)-3,6-dithiaoctane, bbdo = 1,8-bis(benzimidazol-2-yl)-3,6-dithiaoctane and dppt = 3-(pyridin-2-yl)-5,6-diphenyl-1,2,4-triazine, have been isolated and characterised by elemental analysis. NMR and electronic absorption and emission spectral and electrochemical techniques have been used to investigate the solution structures and electronic properties of the complexes. The ¹H and ¹³C spectra of the complexes in solution reveal that the N₂S₂ donor set of the pdto and bbdo ligands is “cis-α” coordinated and the dppt ligand is chelated to Ru(II) through both triazine N2 and pyridine nitrogen atoms. The proton chemical shifts of the phenyl rings of dppt are not affected much upon coordination, supporting the triazine N2 rather than N4 coordination. The anomalous upfield shifts of the H₆₁ and H₆₂ (1) and H₇₂ and H₈₁ (2) protons are caused by the shielding magnetic anisotropy due to the ring currents of the py and tra rings of dppt, which are forced to be coplanar by coordination. The py and bzim rings of pdto and bbdo are obliged to rotate away from dppt and the Ru–N_py and Ru–N_bzim bonds lengthen in order to minimise the steric clashes with dppt. The c.i.s values for 1 are less positive than those for 2 suggesting that the ligand bzim nitrogens of bbdo rather than the py nitrogens of pdto are involved in stronger σ-bonding with Ru(II). Both the complexes display a strong MLCT transition (1, 470; 2, 515 nm) along with intense intraligand transitions in the UV region, and when excited in the MLCT band an emission band (650 nm) is observed for both 1 and 2. In acetonitrile solution they show a quasi-reversible Ru(II)/Ru(III) redox couple (E_1/2, 1, 1.18; 2, 0.90 V). Two more redox processes (E_1/2, 1, −0.97, −1.09; 2, −1.06, −1.42 V) involving the coordinated dppt ligand are also observed. A plot of the difference between the metal oxidation and ligand reduction potentials of the complexes versus the absorption or emission maxima is linear, illustrating that the lowest π^∗ orbitals of dppt are involved in the redox, absorption and emission processes in the complexes. Electrochemical parameterisation of the Ru(II)/Ru(III) redox potentials of the present complexes has been carried out using Lever’s method and the calculated ligand reduction potential E_L(L) correlates well with the observed Ru(II)/Ru(III) redox potentials.     

Uncatalyzed addition of indoles and N-methylpyrrole to 3-formylchromones: synthesis of (chromon-3-yl)bis(indol-3-yl)methanes and E-2-hydroxy-3-(1-methylpyrrol-2-ylmethylene)chroman-4-ones under solvent-free conditions

(Chromon-3-yl)bis(indol-3-yl)methanes and E-2-hydroxy-3-(1-methylpyrrol-2-ylmethylene)chroman-4-ones have been obtained in good yields from 3-formylchromones on reaction with indoles and N-methylpyrrole under solvent-free conditions.     

Synthesis,structures, and properties of bis(4,6-disubstituted 1,3,5-triazin-2-yl) ethers

Reactions of (4,6-disubstituted 1,3,5-triazin-2-yl)trimethylammonium chlorides with glycine sodium salt in the presence of Et₃N afforded bis(triazin-2-yl) ethers instead of the expected triazinylaminoacetic acids. The structures of the resulting compounds were established by the independent synthesis, spectroscopic data, and X-ray diffraction analysis.     

Formation and crystal structures of [(alkoxy)bis(pyridin-2-yl)methanolato-N,O,N]tin(IV) complexes

Reactions of bis(pyridin-2-yl)ketone with tin tetrahalides, SnX₄ (X = Cl or Br), or organotin trichlorides, R^′SnCl₃ (R^′ = Ph, Bu or CH₂CH₂CO₂Me), in ROH (R = Me or Et) readily produces RObis(pyridin-2-yl)methanolato)tin complexes, [5: RO(py)₂C(OSnX₃)] (5: R,X = Me,Cl; Et,Cl; Et,Br) or [6: MeO(py)₂C(OSnCl₂R^′)] (R^′ = Ph, Bu, CH₂CH₂CO₂Me). In addition, halide exchange reaction between SnI₄ and (5: R,X = Me,Cl) occurred to give (5: R,X = Me,I). The crystal structures of six tin(IV) derivatives indicated, in all cases, a monoanionic tridentate ligand, [RO(py)₂C(O⁻)-N,O,N], arranged in a fac manner about a distorted octahedral tin atom. The Sn–O and Sn–N bonds lengths do not show much variation amongst the six complexes despite the differences in the other ligands at tin.     

Synthesis of Novel New 2-(2-(4-((3,4-Dihydro-4-oxo-3-aryl quinazolin-2-yl)methyl)piperazin-1-yl)acetoyloxy)-2-phenyl Acetic Acid Esters

Stereoselective diazotization of (S)-2-amino-2-phenyl acetic acid (L-phenyl glycine) (4) with NaNO₂ in 6% H₂SO₄ in a mixture of acetone and water gave optically pure (S)-2-hydroxy-2-phenyl acetic acid (L-mandelic acid) (5). Esterification, gave (S)-2-hydroxy-2-phenyl acetic acid esters (6). The latter was treated with chloroacetyl chloride in the presence of triethylamine (TEA) in dichloromethane (DCM) to yield (S)-2-chloroacetyloxy phenyl acetic acid ester (2). In another sequence, the reaction of 2-(chloromethyl)-3-arylquinazolin-4(3H)-one (9) treated with N-Boc piperazine, followed by deprotection of the Boc group, to obtain 3-aryl-2-((piperazin-1-yl)methyl) quinazolin-4(3H)-one (3). Reaction of 2 with 3 in the presence of K₂CO₃ and KI gave the title compound, 2-(2-(4-((3,4-dihydro-4-oxo-3-arylquinazolin-2-yl)methyl)piperazin-1-yl) acetoyloxy)-2-phenyl acetic acid esters (1). The structures of all the new compounds obtained in the present work are supported by spectral and analytical data.     

Synthesis, structure and physical properties of LnNi(Sn,Sb)3 (Ln=Pr, Nd, Sm, Gd, Tb)

Five new analogues of the β-CeNiSb₃ family have been synthesized and found to be LnNi(Sn,Sb)₃ and isostructural to the previously reported β-CeNiSb₃. LnNi(Sn,Sb)₃ (Ln=Pr, Nd, Sm, Gd, or Tb) crystallizes in the orthorhombic space group, Pbcm, with lattice parameters of a∼12.9 Å, b∼6.1 Å, c∼12.0 Å. The structure consists of layers of nearly square nets of X (X=Sn/Sb) atoms and highly distorted NiX₆ octahedra. Lanthanide atoms are located between layers of X and NiX₆ octahedra. All analogues are metallic and experimental effective magnetic moments are in agreement with the respective Ln³⁺ calculated moments.     

Synthesis and solution properties of new metal-free and metallo-phthalocyanines containing four bis(indol-3-yl)methane groups

Metallo-phthalocyanines bearing four bis(indol-3-yl)methane groups were successfully prepared by reaction of the corresponding phthalonitriles with anhydrous metal salts [Zn(CH₃COO)₂, NiCl₂ and CoCl₂] in the presence of a catalytic amount of DBU in 2-(dimethylamino)ethanol. The metal-free phthalocyanine was obtained by treating a mixture of the phthalonitrile derivative in similar conditions but in the absence of a metal salt. All of these phthalocyanines are soluble in DMSO, DMF, and pyridine. The products were characterized by IR, NMR, and UV-vis spectroscopy, MALDI-TOF-MS, and thermogravimetric analysis. The aggregation properties of the phthalocyanines were investigated at different concentrations in DMSO. All the phthalocyanines showed monomeric behavior in solution.     

Uncatalyzed addition of indoles and N-methylpyrrole to 3-formylchromones: synthesis and some reactions of (chromon-3-yl)bis(indol-3-yl)methanes and E-2-hydroxy-3-(1-methylpyrrol-2-ylmethylene)chroman-4-ones

(Chromon-3-yl)bis(indol-3-yl)methanes and E-2-hydroxy-3-(1-methylpyrrol-2-ylmethylene)chroman-4-ones have been obtained in good yields from 3-formylchromones on reaction with indoles and N-methylpyrrole under solvent-free conditions. Reactions of (chromon-3-yl)bis(indol-3-yl)methanes with guanidine carbonate and hydrazine hydrate proceed with the participation of the chromone ring system and lead to the formation of the corresponding pyrimidines and pyrazoles bearing the bis(indol-3-yl)methyl moiety.     

Synthesis and crystal structure of complex of Ce(NO_3)_3 with N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl-pyridin-2-yl) hydrazone

Rare earth complexes with organic ligands have been used as luminescence-material usually. Except their luminescent property, the complexes of trivalent lanthanide ions have low toxicity and powerful para-magnetic properties[1,2], so the lanthanide complexes are associated with important biological uses as diag-nostic tools and medicines[36]. Recently, there are some reports on Ce(III) complexes, some of which show anti-cancer activities[7]. S- tetrazines can be used as poly-dentate chelatin…     

C60/C70键联1,4-二-(咔唑-9-亚甲基)苯的电化学行为与双光子吸收

设计合成了C60键联1,4-二-(咔唑-9-亚甲基)苯(5)和C70键联1,4-二-(咔唑-9-亚甲基)苯(6), 用红外、核磁共振和MALDI-TOF质谱进行了表征, 确认了化合物5和6的结构, 用循环伏安法研究了化合物5和6的电化学性质, 并用Z扫描对其双光子吸收性质进行了研究.     

蒙脱土K10-ZnCl2催化下研磨法合成二吲哚甲烷衍生物

蒙脱土K10固载_^ZnCl2是一个有效的环境友好催化剂. 在蒙脱土K10-ZnCl2催化下, 将吲哚与芳香醛混合在研钵中研磨2～8 min, 可得到收率为66%～97%的二吲哚甲烷衍生物. 该方法具有操作简便、反应条件温和、反应时间缩短、 对环境友好等优点.     

Synthesis of substituted 3-(3-chloro-1H-pyrazol-5-yl)quinoxalin-2(1H)ones

Synthetic strategies to gain access to all four isomers of 3-(3-chloro-1H-pyrazol-5-yl)quinoxalin-2(1H)ones with monosubstituted benzo core (i.e., compounds 8a–d) are described. Preparation of these heterocyclic compounds succeeded starting from only two different substituted 2-nitroanilines (i.e., 3-methoxy- and 4-methoxy-2-nitroaniline) in three or five steps, respectively.     

Multi-signalling cation sensing behaviour of a bis(pyridin-2-yl methyl)aniline based hetarylazo dye

We investigated the cation sensing behaviour of a bis(pyridin-2-yl methyl)aniline appended hetarylazo dye via chromogenic and electrochemical transduction channels. The binding pocket constituting both the pyridyl as well as aniline nitrogen atoms acts as recognition site for the cations and consequent perturbation in the intramolecular charge-transfer prevailing in the dye results in the chromogenic response manifested in the form of hypsochromic shift in the intramolecular charge-transfer band and the attendant naked-eye color changes. The dye exhibits significant changes in its electrochemical behaviour in the presence of cations. The experimental results are also rationalized by time-dependent density functional theory (TD-DFT) calculations.     

Synthesis and odor of optically active trans-2,2,6-trimethylcyclohexyl methyl ketones and their related compounds

The synthesis characterized by cationic olefin cyclizations accomplished using ketone enol esters and odor of novel (1R,6S)- and (1S,6R)-2,2,6-trimethylcyclohexyl methyl ketones (5) are described. The stereoselective syntheses of (E)-(1R,6S)- and (E)-(1S,6R)-1-(2,2,6-trimethylcyclohexyl)-2-buten-1-one (6) and (1R,6S)-ethyl 2,2,6-trimethylcyclohexylcarboxylate (7), useful raw materials for flavor and fragrance, starting from the (1R,6S)- and (1S,6R)-5 are also described.     

Synthesis,spectroscopy, electrochemistry,and molecular structure of tetrakis{(E)-2-((pyridin-2-ylimino)methyl)phenolato}(hydroxido)0.5(nitrato)1.5-tetracopper(II) nitrate hydroxide

Abstract

Reaction between (E)-2-((pyridin-2-ylimino)methyl)phenol (HL) and copper(II) nitrate provides tetrakis{(E)-2-((pyridin-2-ylimino)methyl)phenolato}(hydroxido)_0.5(nitrato)_1.5-tetracopper(II) nitrate hydroxide, [(CuL)₄(NO₃)_1.5(OH)_0.5](NO₃)(OH) (1 (a) J. Miao, Z. Zhao, H. Chen, D. Wang, Y. Nie. Acta Cryst., E65, m904 (2009); (b) A. Castineiras, J.A. Castro, M.L. Duran, J.A. Garcia-Vazquez, A. Macias, J. Romero, A. Sousa. Polyhedron, 8, 2543 (1989); (c) I.S. Vasil'chenko, A.S. Antsyshkina, D.A. Garnovskii, G.G. Sadikov, M.A. Porai-Koshits, S.G. Sigeikin, A.D. Garnovskii. Koord. Khimiya, 20, 824 (1994).[Crossref], [Web of Science ®] , [Google Scholar], [Google Scholar], [Google Scholar]). ESI-mass spectra show the ion peaks for the dinuclear species at m/z 565 for [(CuL)₂(HCO₂)]⁺ and 521 for [(CuL)₂+H]⁺ and the mononuclear species at m/z 260 for [(CuL)]⁺. Vibrational spectra show very strong bands at 1604/1546?cm^?1 for ν(C?=?N/C?=?C) and at 1384, 1351?cm^?1 for ν(NO₃^–). Cyclic voltammograms demonstrate an irreversible redox processes for the Cu(II)/Cu(I) and Cu(I)/Cu(0) couples in acetonitrile. X-ray molecular structure determination explores the formation of a cationic tetranuclear copper(II)-complex, in which a deprotonated ligand molecule chelates to one copper ion with the phenolate-O and imino-N atoms. In addition, a phenolate-O atom bridges between two neighboring copper ions and a pyridine-N atom coordinates to a third copper ion, so that each ligand bridges among three copper ions in a κ²N,O:κO:κN' coordination sphere. Thus, the four copper ions and four chelating-bridging ligands assemble primarily into a cationic [(CuL)₄]⁴⁺ complex. The two copper ions are further coordinated by either a nitrate anion (75% occupancy) or a hydroxide anion (25% occupancy) and form the core of a tetranuclear [(CuL)₄(NO₃)_1.5(OH)_0.5]²⁺ cation.     

Synthesis and structure of a complex of copper(II) bromide with bis(benzotriazol-1-yl)methane

The preparation technique of a complex of copper(II) bromide with bis(benzotriazol-1-yl)methane (L), (Cu₂L₂Br₄)_n, is developed. The compound is studied by single crystal and powder X-ray diffraction and static magnetic susceptibility techniques. According to single crystal XRD data, the complex has a layered structure determined by bidentate bridging coordination of L with N(3) and N(3′) atoms to copper(II). The elementary unit of {Cu₂(μ-Br)₂Br₂} polymer has a binuclear structure. The coordination polyhedron is a trigonal pyramid, and the coordination core is CuN₂Br₃. The temperature dependence of effective magnetic moment is studied within an interval of 2–300 K. The nature of the μ_eff(T) dependence indicates that antiferromagnetic exchange interactions dominate in exchange clusters of the complex with an even number of paramagnetic centers. Original Russian Text Copyright ? 2007 by E. V. Lider, A. S. Potapov, E. V. Peresypkina, A. I. Smolentsev, V. N. Ikorskii, A. I. Khlebnikov, and L. G. Lavrenova __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No.3, pp.543–547, May–June, 2007.     

Ethynylation of 2-(furan-2-yl)- and 2-(thiophen-2-yl)pyrroles with acylbromoacetylenes in the Al2O3 medium: relative reactivity of heterocycles

2-(Furan-2-yl)- and 2-(thiophen-2-yl)pyrroles are readily ethynylated with acylbromoacetylenes in the solid Al₂O₃ medium (no solvent, room temperature, 1 h) to afford 5-(furan-2-yl)- and 5-(thiophen-2-yl)-2-acylethynylpyrroles in 39–74% yields. In the case of 2-(furan-2-yl)pyrroles, an alternative ethynylation of the furan ring takes place, the ratio of the furan and pyrrole ring ethynylation products being 1:5–7. No ethynylation of the thiophene ring as well as ethynylation of both heterocycles in a one molecule has been detected. Thus the reactivity of the heterocycles towards the ethynylation system (acylbromoacetylenes/Al₂O₃) falls in the order: pyrrole>furan>thiophene.