Synthesis of (1<Emphasis Type="Italic">R</Emphasis>,2<Emphasis Type="Italic">R</Emphasis>)-1,2-bis-(5-(4-hydroxynaphthalen-1-ylazo)-[1,3,4]thiadiazol-2-yl)-ethane-1,2-diol

In this study, (1R,2R)-1,2-bis-(5-amino-1,3,4-thiadiazol-2-yl)ethane-1,2-diol (2), was synthesized by using (2R,3R)-(+)-Tartaric acid (1) as starting compound. Then the diazo component 3 was obtained from 2 and 1-naphthol. In addition, the structures of the synthesized compounds 2 and 3 were confirmed by elemental analyses, IR, ¹H-NMR, and ¹³C-NMR spectra. __________ Published in Kimiya Prirodnikh Soedinenii, No. 5, pp. 465–466, September–October, 2005.     

Synthesis of glycyrrhizic acid conjugates containing L-lysine

Activated esters and N-hydroxybenzotriazole-N,N′-dicyclohexylcarbodiimide (DCC) or N-hydroxysuccinimide-DCC were used to synthesize conjugates of glycyrrhizic acid (GA) with N^ɛ-carbobenzyloxy-L-lysine [Lys(Z)-OH] and its esters containing two or three amino components. It was shown that the conjugate of GA 30-methyl ester with Lys(Z)-OH possessed anti-HIV-1 activity. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 437–441, September–October, 2006.     

3,3,3-Trifluoro-<Emphasis Type="Italic">N</Emphasis>′-(3-trifluoromethylphenyl)-1,2-propanediamine and its <Emphasis Type="Italic">N</Emphasis>-mono-and <Emphasis Type="Italic">N,N</Emphasis>-dicarboxyethyl derivatives: synthesis,protolytic and complexation properties

3,3,3-Trifluoro-N′-(3-trifluoromethylphenyl)-1,2-propanediamine (5) was synthesized by the reaction of 2-diazo-1,1,1-trifluoro-3-nitropropane or 3,3,3-trifluoro-1-nitropropene with 3-aminobenzotrifluoride followed by the reduction of the nitro group. The Michael 1,4-addition of diamine 5 to acrylic acid occurs only at the N(1) atom and affords N-mono-or N,N-dicarboxyethyl derivatives 6 and 7, depending on the reactant ratio. Protolytic equilibria 5–7 in aqueous solutions were studied by pH-potentiometry and UV spectroscopy. Only the aliphatic amino group can be protonated in an aqueous solution, while the aromatic amino group remains unprotonated even in 12 M HCl. The stability constants of transition metal (Cu²⁺, Ni²⁺, Zn²⁺) complexes with ligands 5–7 were determined by pH-potentiometric titration. The stability of the complexes and selectivity of the ligands toward Cu²⁺ ions increase with an increase in the number of N-carboxyethyl groups. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2465–2469, November, 2005.     

Synthesis and characterization of trichlorogermyl dioic acids: crystal structures and complementary hydrogen bonding motifs in 3-(trichlorogermyl) pentanedioic acid and 2-[(trichlorogermyl)methyl]butanedioic acid

A series of trichlorogermyl-substituted dicarboxylic acids of general formula HOOC–R′–COOH where R′=–CH₂CH(GeCl₃)CH₂– 1, –CH(CH₂GeCl₃)CH₂– 2, –CH(GeCl₃)CH₂– 3 and –CH(CH₃)CH(GeCl₃)– 4 were synthesized by the hydrogermylation reaction of unsaturated acids, such as trans-glutaconic (2-pentenedioic acid), itaconic (methylenebutanedioic acid), fumaric (2-butenedioic acid), and citraconic (2-methyl-2-butenedioic acid) acids with HGeCl₃, which was produced in situ by the reaction of GeO₂ with 37% HCl in presence of NaH₂PO₂ · H₂O. All these compounds were characterized by melting point, CHN analysis, FTIR, and multinuclear NMR (¹H; ¹³C; H,H-COSY). X-Ray crystal structures of 1 and 2 were analyzed to show supramolecular structures in which central Ge atom in each of these structures is four-coordinated with a slightly distorted tetrahedral geometry. Structurally, both compounds adopt supramolecular forms via strong intermolecular O–H–O interactions through 8-membered and 22-membered hydrogen bonded rings. Supplementary material to this paper is available in electronic form at Correspondence: Muhammad Mazhar, Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan.     

Calculations of thermodynamic stability of CpCoC<Subscript>2</Subscript>B<Subscript>9</Subscript>H<Subscript>11</Subscript> cobaltacarborane isomers

Quantum-chemical calculations of the geometry and energies of nine possible isomers of 12-vertex cobaltacarborane CpCoC₂B₉H₁₁ (1) were carried out by the DFT method (PBEPBE/DGDZVP/DGA1). Thermodynamic stability of the isomers increases with increasing distance between the carbon atoms in the cage and is virtually independent of the position of the CpCo vertex. The relative stabilities of the 1,2,3-(17.57 kcal mol⁻¹), 1,2,4-(3.72 kcal mol⁻¹), and 1,2,9-isomers of 1 (0 kcal mol⁻¹) are similar to the corresponding values for the ortho (17.61 kcal mol⁻¹), meta (3.21 kcal mol⁻¹), and para isomers (0 kcal mol⁻¹) of carborane C₂B₁₀H₁₂. The results of the present study confirm a close similarity of the CpCo and BH fragments in metallacarborane chemistry. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1557–1559, July, 2005.     

Syntheses,spectroscopic study and crystal structures of some new <Emphasis Type="Italic">N</Emphasis>-benzoylphosphoric triamides

The reaction of N-benzoylphosphoramidic dichloride with amines afforded some new N-benzoylphos-phoric triamides with formula C₆H₅C(O)NHP(O)(X)₂, X=NH–CH(CH₃)₂ (1), NH–CH₂–CH(CH₃)₂ (2), NH–CH₂–CH(OCH₃)₂ (3), N(CH₃)[CH₂CH(OCH₃)₂] (4) and N(CH₃)(C₆H₁₁) (5) that were characterized by ¹H,¹³C,³¹P NMR, IR spectroscopy and elemental analysis. The structures have been determined for compounds 4 and 5 by X-ray crystallography. These compounds contain one amidic hydrogen atom and form centrosymmetric dimmers via intermolecular –P–O⋯H–N–hydrogen bonds besides weak C–H⋯O hydrogen bonds that lead to three-dimensional polymeric clusters in the crystalline lattice.     

Synthesis and Characterizations of Ferrocenyl Carbonyl Chromium and Cobalt Clusters

Two novel bimetallic complexes, [Cr(CO)₃(η ⁶-C₆H₅)–C≡C–C₆H₄–Fc] (Fc = C₅H₅FeC₅H₄] (1) and [Cr(CO)₃(η ⁶-C₆H₅)–C ≡ C–Fc–C(CH₃)₂–Fc] (3), were synthesized by the Sonogashira coupling reaction. By using of (1) and (3) as ligands to react with Co₂(CO)₈, two others novel polymetallic complexes, [Cr(CO)₃(η ⁶-C₆H₅){Co₂(CO)₆-η ²-μ ²-C≡C–}–C₆H₄–Fc] (2) and [Cr(CO)₃(η ⁶-C₆H₅){Co₂(CO)₆-η ²-μ ²-C≡C–}Fc–C(CH₃)₂–Fc] (4) were obtained. Four carbonyl complexes were characterized by elemental analysis, FT-IR, NMR and MS. The molecular structures of complexes (1), (2) and (4) were determined by single crystal X-ray diffraction. The interactions among the ferrocenyl, Cr(CO)₃ and Co₂(CO)₆-η ²-μ ²-C≡C– units were investigated by cyclic voltammetry.     

Syntheses,spectroscopic and crystallographic characterizations of 4-nitrobenzyloxy derivatives and benzofurans from <Emphasis Type="Italic">ortho</Emphasis>-substituted benzaldehydes and 4-nitrobenzyl bromide

A series of benzyloxybenzaldehyde derivatives (1–3) were prepared by the reactions of 4-nitrobenzyl bromide with 4-hydroxy-3-methoxybenzaldehyde (vanillin), 2-hydroxy-3-methoxybenzaldehyde (o-vanillin) and 2-hydroxy-4-methoxybenzaldehyde. When the reaction time is quite long, benzofuran derivatives (4 and 5) were obtained by the reactions of ortho-hydroxyaldehydes with the 4-nitrobenzyl bromide. Condensation reactions among the three benzyloxybenzaldehyde derivatives (1–3) with 2-aminomethylfuran (furfurylamine) yielded the new imine compounds (6–8). The structures of these aldehydes (1–3), benzofuran derivatives (4 and 5) and imine compounds (6–8) were confirmed on the basis of elemental analyses, IR, ¹H NMR and ¹³C NMR and mass spectroscopy. The solid-state structures of compounds 4–6 were determined by single-crystal X-ray crystallography.     

Triterpenoids from plants of the genus Tamarix

The taraxeran-14-ene-type triterpenoids methyl 3-β-al-D-fridoolean-14-en-28-oate (1), 3-α-[3″,4′-dihydroxytrans-cinnamoyl]-oxy-D-fridoolean-14-en-28-oic acid (2), and β-sitosterol (3) were isolated from the aerial part of plants from the genus Tamarix (T. laxa, T. elongata) (Tamaricaceae). The structures of the triterpenoids were proved using spectral data (IR, UV, PMR, ¹³C NMR, 2D NMR ¹H-¹H COSY, HMQC, HMBC, mass). Compound 1 is new and not previously described in the literature. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 271–273, May–June, 2006.     

Synthesis and crystal structure of inclusion compounds: Trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid with boric acid and tetrabutylammonium salt

Two new inclusion compounds (n-C₄H₉)₄N⁺C₁₈-H₁₃O₄ ⁻·B(OH)₃ (1) and (n-C₄H₉)₄N⁺C₁₈H₁₃O₄ ⁻ (2) were prepared and characterized by X-ray crystallography. Crystal data: compound 1, monoclinic P2(1)/c, a = 1.569 9(1) nm, b = 0.995 5(6) nm, c = 2.293 3(1) nm, β = 109.962(3)°, Z = 4, and R ₁ = 0.0434, wR = 0.075 9; compound 2, monoclinic C2/c, a = 1.400 5(3) nm, b = 1,282 1(2) nm, c = 1.765 7(3) nm, β = 100.388(1)°, Z = 4, and R ₁ = 0.0584, wR = 0.096 6. In the crystal structure of 1, the tetramers formed by two trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid (EADA) anions and two boric acid molecules were connected through O—H⋯O hydrogen bonds to generate a channel type host lattice. The tetra-n-butylammonium cations were stacked to give two columns within each channel with cross-sectional size of about 2.30 nm × 0.93 nm. In the crystal structure of 2, similar honeycomb host lattices with big size were also formed along the [101] direction by three-dimensional accumulation of EADA anions. The tetra-n-butylammonium cations were accommodated in a zigzag fashion within each channel. Translated from Acta Chimica Sinica, 2006, 64(18): 1904–1910 [译自: 化学学报]     

两个三维柱层式单一手性配位化合物:合成、结构和性质（英文）

在溶剂热合成条件下得到2个单一手性配位聚合物,即[Cd3((R)-CIA)2(bipy)2.5(H2O)2]·xGuest(1)和[Zn3((R)-CIA)(bmib)2(H2O)2 Cl]·H2O·xGuest(2)((R)-H3CIA=(R)-5-(1-羧基乙氧基)间苯二甲酸,bipy=4,4′-联吡啶,bmib=1,4-双(2-甲基-1H-咪唑-1-基)苯)。X射线单晶结构分析揭示配合物1和2都是柱层式结构的三维框架。从拓扑分析的角度看,配位物1具有(3,3,3,6,6)-连接的网络,拓扑符号为(4.5^2)2(4.8^2)2(42.6^8.8^3.10^2)(4^2.6^8.8^3.9^2)(5.8.9)2,而配合物2是(3,4,4)-连接的网络,拓扑符号为(6·7^2)2(6·7^5)2(6^2·7^4)。此外,对上述配合物的热稳定性、圆二色谱和荧光性质也做了研究。     

Microcalorimetric Study of the Oscillating Extraction System

The power–time curves of the oscillating extraction system were determined at different temperatures for the extraction of hydrochloric acid and acetic acid with primary amine N₁₉₂₃ (R–CH(NH₂)–R¹), R, R ¹ represent alkyl of C_9–11 in chloroform using the titration microcalorimetric method. The apparent activation energy was calculated from the induction period (t _in), the first oscillation period (t ^p.1) and the second oscillation period (t _p.2). This revised version was published online in August 2006 with corrections to the Cover Date.     

Electrospray Ionization Mass Spectrometry of Palladium(II) Quinolinylaminophosphonate Complexes

The mass spectrometric behavior of palladium(II) halide complexes of three types of quinolinylaminophosphonates, diethyl and dibutyl esters of [α-anilino-(quinolin-2-yl)methyl]phosphonic (L1, L2), [α-anilino-(quinolin-3-yl)methyl]phosphonic (L3, L4), and [α-(quinolin-3-ylamino)-N-benzyl]phosphonic acid (L5, L6), was investigated under positive ion electrospray ionization conditions. Each type of ligand forms complexes with different metal–ligand interactions. Mononuclear dihalide adducts cis-[Pd(L1/L2)X₂] (1–4) and trans-[Pd(L3/L4)₂X₂] (5–8) as well as dinuclear tetrahalide complexes [Pd₂(L5/L6)₃X₄] (9–12) (X = Cl, Br) are formed by metal bonding either through the quinoline or both the quinoline and amino nitrogen atoms. The sodiated molecule [M + Na]⁺ is observed in the mass spectra of all the complexes, and its abundance as well as the fragmentation pathway depend on the type of the complex. In the cis complexes (1–4) the initial decomposition goes under two fragmentation routes: those in which the sodium molecular adduct sequentially loses halides HX/NaX and those in which this loss is in the competition with the loss of dialkyl phosphite. The predominant pathways for decomposition of trans dihalide (5–8) and tetrahalide (9–12) complexes include three competitive reactions; the loss of halides, dialkyl phosphites and the intact phosphonate ligand molecule and its fragments formed by ester dissociation or complete loss of the phosphonate ester moiety. A series of acetonitrile adducts and cluster ions derived from dimolecular clusters [2M + Na]⁺ were also detected. The most important fragmentation patterns are rationalized and supported by the MS ⁿ studies.     

Different coordination modes and supramolecular aggregations in copper(II) pentane-2,4-dionato compounds with 2-pyridone and 3-hydroxypyridine

Abstract  

Copper(II) bis(pentane-2,4-dionato-κ² O,O′) compounds with 2-pyridone (1) and 3-hydroxypyridine (2) were prepared by the reaction of bis(pentane-2,4-dionato-κ² O,O′)copper(II) with selected ligands. The coordination of Cu(II) in both compounds is square pyramidal with the fifth coordination site occupied by the carbonyl oxygen atom of the 2-pyridone ligand in 1 and by the nitrogen atom of 3-hydroxypyridine in 2. The X-ray crystallographic studies revealed different crystal aggregation influenced by the ability of the 2-pyridone ligand to act as a hydrogen bond donor and acceptor, and 3-hydroxypyridine acting only as a hydrogen bond donor. Intermolecular N–H···O hydrogen bonding forms dimers in 1 and infinite chains in 2. Three-dimensional aggregation is achieved by π–π interactions and C–H···π (arene) hydrogen bonding.     

A furostanol saponin and phytoecdysteroid from roots of <Emphasis Type="Italic">Helleborus orientalis</Emphasis>

A furostanol saponin mixture and a known phytoecdysteroid were isolated from the roots of Helleborus orientalis Lam. Their structures were established as 26-[(β-D-glucopyranosyl)oxy]-22α-hidroxyfurosta-5,25(27)-dien-1β,3β,11α-triol (1a), 26-[(β-D-glucopyranosyl)oxy]-22α-methoxyfurosta-5,25(27)-dien-1β,3β,11α-triol (1b), and 20-hydroxy-β-ecdyson-3-O-β-D-glycoside (2). Acid hydrolysis of 1a,b gave (1β,3β,11α,22α)-22,26-dimethoxyfurosta-5,25(27)-dien-1,3,11-triol (aglycone 1) and of 2 gave 20-hydroxy-β-ecdyson (aglycone 2). Their structures were elucidated by spectral analysis. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 75–77, January–February, 2007.     

A novel 2D organic-inorganic hybrid 3d–4f polyoxometalate built by [Gd(α-PW11O39)2]11? units and [Cu(Dap)2]2+ bridges

A novel 2D organic-inorganic hybrid 3d–4f polyoxometalate [Cu(Dap)₂(H₂O)][Cu(Dap)₂]_4.5[Gd(α-PW₁₁O₃₉)₂] · 5H₂O (I) (Dap = 1,2-diaminopropane) built by [Gd(α-PW₁₁O₃₉)₂]¹¹⁻ units and [Cu(Dap)₂]²⁺ bridges has been synthesized hydrothermally by the reaction of GdCl₃, CuCl₂ · 2H₂O, Na₉[A-α-PW₉O₃₄] · 7H₂O, and Dap and characterized by elemental analysis, IR spectrum, UV spectrum, powder X-ray diffraction, and single-crystal X-ray diffraction. Single-crystal structural analysis shows that I displays an interesting 2D 3d–4f heterometallic sheet architecture with a 5-connected topology constructed from 1: 2-type [Gd(α-PW₁₁O₃₉)₂]¹¹⁻ subunits and [Cu(Dap)₂]²⁺ bridges. To the best of our knowledge, I represents a rare organic-inorganic hybrid 2D 3d–4f heterometallic monovacant Keggin phosphotungstate.     

Synthesis,crystal structures,and magnetic properties of two manganese(II) coordination polymers bearing 1,1′-biphenyl-3,3′-dicarboxylate ligands

Two Mn(II) coordination polymers, namely [Mn(bpda)] _n (1) and [Mn(bpda)(bpy)_0.5] _n (2) (H₂bpda = 1,1′-biphenyl-3,3′-dicarboxylic acid and bpy = 4,4′-bipyridine), have been synthesized from H₂bpdc, bpy, and MnSO₄·2H₂O under hydrothermal conditions. The complexes were characterized by physicochemical and spectroscopic methods, as well as by X-ray crystallography. Compound 1 possesses a 3D structure consisting of carboxylate-bridged edge-sharing Mn–O–Mn double chains. Compound 2 features a 3D open structure with a dinuclear Mn(II) secondary building unit. Magnetic susceptibility measurements of compounds 1 and 2 exhibit antiferromagnetic interactions between the nearest Mn(II), with J = –11.3 cm⁻¹ and g = 2.12 for 1, and J = –13.5 cm⁻¹ and g = 2.12 for 2.     

A new flavonol derivative from <Emphasis Type="Italic">Fagopyrum dibotrys</Emphasis>

A new flavonol derivative 3, 8-dihydroxy-10-methoxy-5-H-isochromeno[4, 3-b]chromen-7-one (1) together with four known compounds, glutinone (2), luteolin (3), acacetin 7-O-α-L-rhamnopyranosyl- (1→6)-β-D-glucopyranoside (4), and rutin (5) were isolated from the dried roots of Fagopyrum dibotrys. Their structures were determined by UV, IR, MS, ¹H, and ¹³C NMR spectroscopic analysis, including 2D NMR. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 567–568, November–December, 2008.     

Oxygen- versus carbon-coordination of the alpha-stabilized phosphorus ylide Ph<Subscript>3</Subscript>P=C(H)R in palladacycles bearing secondary amines

The ortho-metalated complex [Pd(x){κ ² (C,N)-[C₆H₄CH₂NRR′ (Y)}] (2a–4a and 2b–3b) was prepared by refluxing in benzene equimolecular amounts of Pd(OAc)₂ and secondary benzylamine [a, EtNHCH₂Ph; b, t-BuNHCH₂Ph followed by addition of excess NaCl. The reaction of the complexes [Pd(x){κ ² (C,N)-[C₆H₄CH₂NRR′ (Y)}] (2a–4a and 2b–3b) with a stoichiometric amount of Ph₃P=C(H)COC₆H₄-4-Z (Z = Br, Ph) (ZBPPY) (1:1 molar ratio), in THF at low temperature, gives the cationic derivatives [Pd(OC(Z-4-C₆H₄C=CHPPh₃){κ ² (C,N)-[C₆H₄CH₂NRR′(Y)}] (5a–9a, 4b–6b, and 4b′–6b′), in which the ylide ligand is O-coordinated to the Pd(II) center and trans to the ortho-metalated C(6)H(4) group, in an “end-on carbonyl”. Ortho-metallation, ylide O-coordination, and C-coordination in complexes (5a–9a, 4b–6b, and 4b′–6b′) were characterized by elemental analysis as well as various spectroscopic techniques.     

Chemical Constituents of Brown Rice Grain (<Emphasis Type="Italic">Oryza sativa</Emphasis>)

One new compound 3,7,11,15,19-pentamethyl-9α,10α,11α,17α,18α-pentahydroxy-n-tetracosan-1-oxy-p-hydroxycaffeoate (oryzaterpenyl caffeoate) (1), together with three known fatty acids linoleic acid, stearic acid and myristic acid were isolated and identified from the rice grain of Oryza sativa. The structure of the new compound was elucidated by 1D and 2D NMR spectroscopic techniques (¹H-¹HCOSY, ¹H-¹³C HETCOR) aided by EI-MS, and IR spectra. __________ Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 535–537, November–December, 2005.