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ABSTRACT: AbstractSynthesis and X-ray structural determination of three phosphorus compounds are reported. (3b) is monoclinic P2(1)/c with a=11.852(1), b=12.825(1), c=12.445(1) Å, β=103.693(1)º; (4a) and (4b) are monoclinic P2(1)/n with a=12.1422(16), b=9.0860(12), c=14.845(2) Å, β=96.498(3)º for (4a), and a=12.2714(16), b=9.2812(12), c=14.800(2) Å, β=97.176(2)º for (4b). They all exhibit distorted tetrahedral geometry about the P atom. Ph2P(X)NHC7H7 (X=S (4a) and X=Se (4b)) show typical P–S and P–Se double bond distances and P–N single bonds, while P–S bond in 1-Ad2P(S)Cl (3b) is comparable to P–S single bonded probably due to the largeness of 1-adamantyl groups.
Graphical AbstractSynthesis and X-ray structural determination of 1-Ad2P(S)Cl (3b), Ph2P(S)NHC7H7 (4a) and Ph2P(Se)NHC7H7 (4b) are reported.
Journal of Chemical Crystallography 04/2012; 39(7):530-534. · 0.57 Impact Factor
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ABSTRACT: In the title compound, C(16)H(18)O(3)S, the dihedral angle between the benzene rings is 75.48 (8)°. The absolute configuration at the stereogenic S-atom center was determined as S. The crystal structure is stabilized by inter-molecular C-H⋯O contacts.
Acta Crystallographica Section E Structure Reports Online 11/2011; 67(Pt 11):o2950. · 0.35 Impact Factor
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ABSTRACT: The chemical constituents of the organic extracts from the rhizomes of Ligusticum porteri were isolated, characterised and identified as Z-ligustilide, Z-butylidenephthalide, diligustilide, tokinolide B, riligustilide, senkyunolides F and I, ferulic acid, among other known compounds. The preparation of 4,5-dehydrotokinolide B from tokinolide B is reported, and its structure confirmed by X-ray analysis. The sedative and spasmolytic activities of some of these natural products and derivatives were evaluated by applying them to in vivo and in vitro models. Several of these dimeric phthalides displayed sedative and spasmolytic properties that may correlate with some popular uses of L. porteri.
Natural product research 08/2011; 25(13):1234-42. · 1.01 Impact Factor
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ABSTRACT: Optically pure (S)-(-)-xylopinine 2 was prepared in three steps in 52% overall yield. Thus, condensation of the carbanion derived from (S)-4 with the (S)-(E)-sulfinylimine 5 gave a 2:1 mixture of tetrahydroisoquinolines 6a and 6b, differing only in configuration at sulfur. N-Desulfinylation of this mixture gave the diastereomeric sulfoxides which, without separation, were converted into (S)-(-)-xylopinine (2) with loss of the sulfinyl moieties under Pictet-Spengler conditions. This unprecedented ipso electrophilic substitution of a sulfinyl group may have synthetic implications beyond that described in this work.
The Journal of Organic Chemistry 06/2011; 76(12):5036-41. · 4.45 Impact Factor
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ABSTRACT: Three new friedelane-type triterpenes, 1,2-dehydro-2,3-secofriedelan-3-oic acid (1), 1β-hydroxyfriedelin (2), and 3β-hydroxyfriedelan-23-oic acid (3), and the known compounds friedelin-3,4-lactone (4), acetyl aleuritolic acid (5), 4-hydroxy-5-propionyl-1,3-di-O-methylpyrogallol, elemicin, and (-)-syringaresinol were isolated from the leaves of Garcia parviflora. The structures of 1-3 were elucidated by spectroscopic methods, including 1D and 2D NMR, HREIMS, X-ray, and CD analysis. Some derivatives of 2 (6-14) were prepared via oxidation, reduction, and esterification. The natural triterpenes and the semisynthetic friedelane derivatives were tested for cytotoxic activity against human cancer cell lines U251, PC-3, K562, HCT-15, MCF-7, and SKLU-1. Compound 5 was cytotoxic against U251 cells.
Journal of Natural Products 10/2010; 73(11):1839-45. · 3.13 Impact Factor
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ABSTRACT: Equimolar and excess ratio reactions of AlMe(3) and Al(i)Bu(3) with the ligands 4,5-(P(E)Ph(2))(2)tzH (tz = 1,2,3-triazole; E = O (1), S (2), Se(3)) were performed, showing a vast variety of coordination modes. The products obtained, [AlR(2){kappa(2)-O,O'-[4,5-(P(O)Ph(2))(2)tz]}] (R = Me (4), (i)Bu (5)), [AlR(2){kappa(3)-N,N',S-[4,5-(P(S)Ph(2))(2)tz]}(mu-tz)](2) (R = Me (6), R = (i)Bu (7)), [AlMe(2){kappa(2)-N,Se-[4,5-(P(Se)Ph(2))(2)tz]}] (8), [Al{kappa(2)-N,Se-[4,5-(P(Se)Ph(2))(2)tz]}(3)] (9), [AlR(2){kappa(2)-O,O'-[4,5-(P(O)Ph(2))(2)tz]}-(N'-AlR(3))] (R = Me (10), (i)Bu (11)), and [AlR(2){kappa(2)-N,S-[4,5-(P(S)Ph(2))(2)tz]}-(N'-AlR(3))] (R = Me (12), R = (i)Bu (13)), were characterized by spectroscopic methods, and the structures of 1, 4, 6, 7, 9, 10, and 12 were obtained through X-ray diffraction studies. Theoretical calculations were performed on the deprotonated ligands and on selected compounds to obtain information regarding the coordination variety observed for these compounds.
Inorganic Chemistry 07/2009; 48(13):5874-83. · 4.60 Impact Factor
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ABSTRACT: The preparation of novel alkali metal chalcogenides supported by multidentate nitrogen rich ligands is reported. Treatment of the ligand precursors [H{(4,5-(P(E)Ph(2))(2)tz}] (E = S (1a), Se (1b)) with organolithium reagents or elemental sodium and potassium in tetrahydrofuran (THF) leads to the isolation of 2-7 in high yields. These compounds were characterized by elemental analysis, IR spectroscopy, mass spectrometry, solution and solid-state multinuclear NMR spectroscopy, and single crystal X-ray diffraction analysis. In the solid state, 2, 4, and 5 are dimers that contain bimetallic six-membered (M(2)N(4)) rings (M = Li, Na). In 3, the discrete monomer [Li{4,5-(P(Se)Ph(2))(2)tz}(thf)(2)] (tz = 1,2,3-triazole) contains a five-membered CPSeLiN ring which adopts an envelope conformation. The polymeric arrangement [K{4,5-(P(S)Ph(2))(2)}tz](infinity) in 6 displays different bonding modes based on the hapticity of the ligand upon binding to the potassium atom. In compounds 2-6, the presence of secondary bonding features the alkali metal chalcogen bonds.
Inorganic Chemistry 03/2009; 48(6):2518-25. · 4.60 Impact Factor
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ABSTRACT: The unique alumophosphite reagent LAl(SH)(mu-O)P(OEt)2 was prepared and used for the synthesis of the heterobimetallic alumophosphites [{kappa2-S,P-LAl(S)(mu-O)P(OEt)2}2Zn] and [{kappa4-S,O,O-LAl(SLi)(mu-O)P(OEt)2}2]. The first contains a rare example of two carbon-free five-membered heterocycles (Al-S-Zn-P-O) connected in a spiro fashion through the zinc atom, whereas the second possesses an unknown example of a coordination environment of a phosphite unit M-O-P(mu-OEt)2M with an uncoordinated lone electron pair on the phosphorus center.
Inorganic Chemistry 01/2008; 46(25):10749-53. · 4.60 Impact Factor
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ABSTRACT: The heterobimetallic aluminosilicate [LAl(SLi)(micro-O)Si(OLi.2thf)(O(t)Bu)(2)](2) was prepared from the LAl(SH)(micro-O)Si(OH)(O(t)Bu)(2) (L = [HC{C(Me)N(Ar)}(2)](-), Ar = 2,6-di-(i)Pr(2)C(6)H(3)) ligand, which can also be hydrolyzed to LAl(OH.thf)(micro-O)Si(OH)(O(t)Bu)(2)- leading to the first aluminosilicate-dihydroxide soluble in organic solvents.
Chemical Communications 12/2007; · 6.17 Impact Factor
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ABSTRACT: Z-Ligustilide, a naturally occurring phthalide isolated from Ligusticum porteri, underwent Diels–Alder reactions with different dienophiles yielding novel tricyclic products with potentially interesting biological properties. Where selectivity was possible, the reactions performed showed regio- and stereoselectivity. The experimental results with ethyl acrylate were compared with the selectivity predicted by ab initio calculations.
Tetrahedron Letters 06/2007; 48(24):4215–4218. · 2.68 Impact Factor
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Angewandte Chemie 03/2007; 119(16):2953 - 2956.
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Angewandte Chemie International Edition 02/2007; 46(16):2895-8. · 13.45 Impact Factor
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ABSTRACT: The reaction of the LAl(SH)(µ‐O)P(OEt)2 (L=HC[C(Me)NAr]−, R=2,6‐di‐iPr2C6H3) ligand (1) with GaMe3 in toluene led to the isolation of a unique heterobimetallic aluminophosphite [κ2‐P, S‐LAl(µ‐S)(µ‐O)P(OEt)2]GaMe2 (2). Compound 2 is a potential secondary building unit (SBU) for heterometallic materials and represents the first example of structurally characterized lipophilic phosphite of the p‐block metals, in which the metal is coordinated by the phosphorus atom. Moreover, it represents the first structurally characterized example where a gallium atom is coordinated to both, sulfur and phosphorus atoms. Furthermore, it contains a rare carbon‐free “true” 5‐membered heterocycle Al‐O‐P‐Ga‐S.
Synthesis and Reactivity in Inorganic Metal-Organic and Nano-Metal Chemistry 01/2007; Metal-Organic(and Nano-Metal Chemistry):741-744. · 0.47 Impact Factor
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ABSTRACT: Three novel aluminum-containing tin(IV) heterobimetallic sulfides are reported. The reaction of [LAl(SLi)2(THF)2]2 (1) [L = HC(CMeNAr)2, Ar = 2,6-iPr2C6H3] with Ph2SnCl2, Me2SnCl2, and SnCl4 in THF respectively afforded LAl(mu-S)2SnPh2 (2), LAl(mu-S)2SnMe2 (3), and LAl(mu-S)2Sn(mu-S)2AlL (4) in moderate yields. Compounds 2, 3, and 4 were characterized by elemental analysis, NMR, electron-impact mass spectrometry, and single-crystal X-ray structural analysis.
Inorganic Chemistry 05/2006; 45(8):3312-5. · 4.60 Impact Factor
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ABSTRACT: The reactions between the rhenium(I) complexes [ReBr(CO)5], [Re2Br2(CO)6(THF)2], and [ReOTf(CO)5] and Na[Ph2P(O)NP(O)Ph2] in toluene and THF under reflux and in dichloromethane at room temperature, respectively, afforded the complex Na[Re2(CO)6{μ-Ph2P(O)NP(O)Ph2-κ2O}3] in good to medium yields; an X-ray crystallographic study in the solid state revealed that the sodium atom is enclosed in the cage formed by two −Re(CO)3 fragments joined by three end-bound [Ph2P(O)NP(O)Ph2] ligands.
03/2006;
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ABSTRACT: The pyrazolato complexes [(Me(2)pz)(THF)Li] (1), [((t)Bu(2)pz)Li](4) (2), [((t)Bu(2)pzH)((t)()Bu(2)pz)Li](2) (2a), [(Me(2)pz)Na] (3), [((t)Bu(2)pz)Na](4), [((t)Bu(2)pz)(6)(OH)Na(7)] (4a), [((t)Bu(2)pz)(18-crown-6)Na] (4b), and [((t)Bu(2)pz)K] (5) were synthesized by metalation reactions between R(2)pzH (R = Me, (t)()Bu) and alkyllithium, elemental sodium, or potassium. All the complexes were characterized by spectroscopic methods and microanalysis, and in addition, the crystal structures of 2, 2a, 3, 4a, 4b, and 5 were obtained by single-crystal X-ray diffraction. They show monomeric, dimeric, cluster, and 1D chain structures in the solid state. Ab initio calculations on the structure and stabilities of the monomeric pzM complexes were performed at the MP2 level of theory showing good agreement with the coordination preferences of the pyrazolato ligand to a particular alkali ion.
Inorganic Chemistry 02/2006; 45(1):286-94. · 4.60 Impact Factor
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ABSTRACT: The [(SePPh2)2N]− ligand 1c forms stable tris(chelates) with the SbIII, BiIII, and InIII ions. The crystal and molecular structures of the resulting compounds 3, 4, and 5 were determined by X-ray diffractometry. The coordination geometry around the metal centers can be described as a distorted octahedron. This feature and the results obtained by comparing the structures with their sulfur and oxygen analogs lead us to conclude that in both SbIII and BiIII compounds the arrangement around the metals suggests a stereochemically nonactive electron lone pair.
Berichte der deutschen chemischen Gesellschaft 01/2006; 129(8):919 - 923. · 2.94 Impact Factor
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ABSTRACT: The novel M[(OPPh2)2N]2.nTHF (M = Sr (2), Ba (3)) complexes were prepared and characterized. Upon exposure to atmospheric oxygen, 2 and 3 were transformed to the dinuclear species Sr2-[(OPPh2)2N]4.2C3H6O3 (4) and Ba(2)[(OPPh2)2N]4.2C4H8O3 (5), respectively. Compounds 4 and 5 contain coordinated carboxylic acids obtained from the oxidative degradation of DME and THF, respectively, which were used as solvents for crystallization.
Inorganic Chemistry 11/2005; 44(20):6924-6. · 4.60 Impact Factor
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ABSTRACT: The syntheses and molecular structures of [M{N(SeP(i)Pr2)2-Se,Se'}2][M = Sn(2), Se(3)] are described, these complexes consist of discrete, monomeric molecules featuring MSe4 cores that comprise true square-planar geometries.
Dalton Transactions 04/2005; · 3.84 Impact Factor
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Chemical Communications 03/2004; · 6.17 Impact Factor
