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1.
YU An-Guang WANG Nai-Xing ZHANG Jun-Ping YANG Yun-Xu WANG Wu-Wei SHENG Rui-Long 《有机化学》2004,24(Z1):31-32
Benzopyran compounds possess diverse pharmacological properties such as β-blockade, anticonvulsant and antimicrobial.[1,2] Our interest has been focused on the synthesis of 1-[6-Fluoro-2S]-3H,4H-dihydro-2H-2-chromenyl]-(1R)-1,2-ethanediol (6) and 1-[6-fluoro-(2R)-3H,4H-dihydro-2H-2-chromenyl]-(1R)-1,2-ethanediol (7) which are particularly convenient precursor to (S,R,R,R)-NE (8). 8 containing four asymmetrical carbon atoms was reported to be the most active isomer.[3] Chandrasekhar[4] has reported on the synthesis of 8. The key step to synthesize this compound is to obtain the chiral chromanone 6 and 7. 6 was accomplished in 8 steps by the Clasien rearrangement and a one-pot Sharpless asymmetric epoxidation, but the compound 7 was accomplished in 10 steps. Johannes[5] used Zr-catalytic kinetic resolution of allylic ethers and Mo-catalyzed chromene formation to synthesize 8 in 14 steps. However both of the methods request many synthetic steps and expensive reagents. 相似文献
2.
Introduction Asarelativelynewmemberofnaturalalkaloidswith2 ,6 disubstituted 3 piperidinolskeleton ,irnigaine 1wasisolatedfromthetubersofArisarumVulgare (Araceae)in1995byMelhaouiandBode .1Itsstructureandrelativeconfigurationswereelucidatedby1HNMRstudiesandtheabsoluteconfigurationwasproposedonthebasisofitsopti calrotation .1Soonafterthen ,Meyerandhisco workersreportedthefirstsynthesisof (- ) (2R ,3R ,6S) irni gaineandtheconfigurationconfirmation .Althoughtheirsynthesisroutewasshortan… 相似文献
3.
V. V. Sharutin I. V. Egorova O. K. Sharutina T. K. Ivanenko N. Yu. Adonin V. F. Starichenko M. A. Pushilin A. V. Gerasimenko 《Russian Journal of Coordination Chemistry》2005,31(1):2-8
X-ray diffraction study of tetranuclear organobismuth complexes Bi4(O)2(O2CC6H2F3-3,4,5)8 · 26-C6H6 and Bi4(O)2(O2CC6H2F3-3,4,5)8 · 2(C6H4Me2-1,4) revealed four Bi atoms connected through the bridging carboxylate ligands and the O atoms. The coordination sphere of the terminal Bi atoms includes the chelate carboxylate ligand and the 6-arene molecule. The bridging O atoms are tricoordinated, the distances between the terminal Bi atom and the center of benzene molecule (1,4-dimethylbenzene) are 3.024 Å(3.131 Å).Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 1, 2005, pp. 4–11.Original Russian Text Copyright © 2005 by Sharutin, Egorova, Sharutina, Ivanenko, Adonin, Starichenko, Pushilin, Gerasimenko. 相似文献
4.
Chunlin Ma Zhenxing Li Qianli Li Fei Wang Rufen Zhang Qingfu Zhang 《Structural chemistry》2014,25(3):949-958
Four new triorganotin(IV) complexes, [R3Sn(O2SeC6H4-4-Et)]4 (R = Me 1), [R3Sn(O2SeC6H4-4-Et)] n (R = Ph 2), [R3Sn(O2SeC6H4-2-Et)] n (R = Me 3; Ph 4) have been synthesized by the treatment of 4-ethylbenzeneseleninic acid, 2-ethylbenzeneseleninic acid, and the corresponding triorganotin(IV) chloride with sodium ethoxide in methanol. All of the complexes were characterized by elemental analysis, FT-IR, NMR (1H, 13C, and 119Sn) spectroscopy, TGA, and X-ray crystallography. Crystal structures show that all of the complexes are generated by the bidentate oxygen atoms and the five-coordinated tin centers with trigonal bipyramid geometry. The structural analyses reveal that complex 1 has a centrosymmetric tetranuclear triorganotin selenite with 16-membered macrocycle, which is formed by trimethyltin and ligand alternate linking. A series of C–H···O and π–π stacking interactions in complex 1 play an important function in the supramolecular aggregation. Complex 3 has two 1D spring-like chiral helical chains and crystallizes in the monoclinic space group P21, which is chiral. Complex 2 and 4 are both 1D infinite neutral chain polymers and complex 2 forms a 2D supramolecular framework through intermolecular C–H···O interactions. 相似文献
5.
A simple approach involving refluxing appropriately disubstituted thiosemicarbazide 8 in presence of formic acid for the synthesis of 1, a potent azole antifungal agent, has been described. 相似文献
6.
YU Yang LIU Dan HU Wei-wei LI Jia PENG Yu ZHOU Qi YANG Fen LI Guang-hua SHI Zhan FENG Shou-hua 《高等学校化学研究》2012,28(2):186-190
Three metal molybdate hydrates,Fe(H2O)2(MoO4)2·H3O(FeMo),NaCo2(MoO4)2(H3O2)(CoMo)and Mn2(MoO4)3·2H3O(MnMo),were synthesized by the mixed-solvent-thermal methods and characterized by singlecrystal X-ray... 相似文献
7.
Although messenger mediated spectroscopy is a widely-used technique to study gas phase ionic species, effects of messengers themselves are not necessarily clear. In this study, we report infrared photodissociation spectroscopy of H(+)(H(2)O)(6)·M(m) (M = Ne, Ar, Kr, Xe, H(2), N(2), and CH(4)) in the OH stretch region to investigate messenger(M)-dependent cluster structures of the H(+)(H(2)O)(6) moiety. The H(+)(H(2)O)(6), the protonated water hexamer, is the smallest system in which both the H(3)O(+) (Eigen) and H(5)O(2)(+) (Zundel) hydrated proton motifs coexist. All the spectra show narrower band widths reflecting reduced internal energy (lower vibrational temperature) in comparison with bare H(+)(H(2)O)(6). The Xe-, CH(4)-, and N(2)-mediated spectra show additional band features due to the relatively strong perturbation of the messenger. The observed band patterns in the Ar-, Kr-, Xe-, N(2)-, and CH(4)-mediated spectra are attributed mainly to the "Zundel" type isomer, which is more stable. On the other hand, the Ne- and H(2)-mediated spectra are accounted for by a mixture of the "Eigen" and "Zundel" types, like that of bare H(+)(H(2)O)(6). These results suggest that a messenger sometimes imposes unexpected isomer-selectivity even though it has been thought to be inert. Plausible origins of the isomer-selectivity are also discussed. 相似文献
8.
Syntheses and Crystal Structures of Sm(OAr)2(THF)3·THF and Sm(OAr)2(DME)2 (Ar = C6H2-tert-Bu3-2,4,6)
Reaction of SmI2(THF)x with 2 equivalents of NaOAr (Ar = C6H2-tert-Bu3-2,4,6)1,2-dimethoxyethane (DME) leads to the ligand-exchange reaction, and a DME-solvated complex of Sm(Oar)2(DME)2 2 was obtained. Complex 1 crystallizes in monoclinic, space group P21/c with a =10.366(5), b = 33.024(15), c = 16.123(7) (A), β= 93.197(8)°, V= 5511(4) A3, Z= 4, C52H9oO6Sm, Mr = 961.59, Dc = 1.159 g/cm3, F(000) = 2048,μ(MoKα) = 1.107 mm-1, R = 0.0844 and wR = 0.1401for 4694 observed reflections. Complex 2 crystallizes in monoclinic, space group C2/c with a =27.222(5), b = 10.6140(19), c = 17.398(4) (A), β = 110.245(3)°, V = 4716.4(16) (A)3, Z = 4,C44H78O6Sm, Mr = 853.41, Dc = 1.202 g/cm3, F(000) = 1808,μ(MoKα) = 1.285 mm-1, R = 0.0361and wR = 0.0830 for 5210 observed reflections. 相似文献
9.
《Tetrahedron: Asymmetry》2001,12(1):89-94
Synthesis of key intermediates leading to 2-iso-oxacephems was carried out starting from l- and d-threonine. As predicted in our previous paper (Tetrahedron Lett. 1995, 36, 8303–8306) all diastereomers of 2-iso-oxacephems can be prepared from the appropriate enantiomers of the amino acid threonine. The absolute configuration of the 2,3- and α-carbon atoms in the β-lactam structure was determined by X-ray crystallographic studies. 相似文献
10.
11.
The crystals of copper(I) π-complexes CuBF4 · 2C6H4N3(OC3H5) · H2O (I) and CuCF3COO · C6H4N3(OC3H5) (II) were obtained by alternating-current electrosynthesis and studied by X-ray diffraction: I, space group P21/n, a = 10.226(8), b = 13.233(10), c = 16.30(1) Å, β = 98.13(1)°, V = 2249(2) Å3, Z = 4, R = 0.0705, 577 reflections; I, space group P $ P\bar 1 The crystals of copper(I) π-complexes CuBF4 · 2C6H4N3(OC3H5) · H2O (I) and CuCF3COO · C6H4N3(OC3H5) (II) were obtained by alternating-current electrosynthesis and studied by X-ray diffraction: I, space group P21/n, a = 10.226(8), b = 13.233(10), c = 16.30(1) ?, β = 98.13(1)°, V = 2249(2) ?3, Z = 4, R = 0.0705, 577 reflections; I, space group P
, a = 8.8625(7), b = 9.0647(4), c = 9.1650(5) ?, α = 68.37(2)°, β = 85.31(3)°, γ = 69.86(2)°, V = 646(4) ?3, Z = 2, R = 0.1354, 2669 reflections. In compound I, the tetrahedrally distorted trigonal pyramidal environment of the copper atom comprises two nitrogen atoms of two organic
molecules (L), the C=C bond of another L molecule, and the O atom of the water molecule. Due to the bridging function of L
molecule, infinite chains [Cu · 2C6H4N3(OC3H5) · H2O]
n
are formed in the structure along the y axis. The chains are, in turn, assembled into layers through strong O-H…F hydrogen bonds involving both hydrogen atoms of
the water molecule and fluorine atoms of the BF4− anion. In compound II, two bridging oxygen atoms of two trifluoroacetate anions and two copper atoms form a centrosymmetric dimer. The nitrogen
atom of the benzotriazole ring of one molecule L and the C=C double bond of the allyl group of the other molecule L complete
the distorted coordination tetrahedron of the metal atom. Owing to the bridging function of the L molecule, the [CuCF3COO · C6H4N3(OC3H5)]2 dimers are connected to form infinite double chains associated in a three-dimensional framework by only weak interactions.
The replacement of the covalently bonded trifluoroacetate anion by an outer-sphere tetrafluoroborate ion opens up the possibility
for metal atom binding to three L molecules simultaneously.
Original Russian Text ? E.A. Goreshnik, M.G. Mys’kiv, 2008, published in Koordinatsionnaya Khimiya, 2008, Vol. 34, No. 11,
pp. 826–830. 相似文献
12.
V. V. Sharutin O. K. Sharutina O. V. Chagarova O. V. Molokova 《Russian Journal of General Chemistry》2011,81(11):2246-2251
The organoantimony peroxide (Ar2SbO)4(O2)2 (Ar = C6H3OMe-2, Br-5) was synthesized by the oxidation of Ar3Sb with hydrogen peroxide in the presence or acetoxime or acetophenone oxime in dioxane. The product crystallizes with various content of the solvent molecules in the crystal unit cell [1.5 (I) and 6 (II), respectively]. An X-ray diffraction analysis of the solvates was performed. Four antimony atoms in the peroxide are in the octahedral coordination, and are linked through bridging oxygen atoms and two peroxide groups. The distances Sb-C, Sb-Obridge, Sb-Operoxide, O-O and Sb...Sb are 2.117–2.122, 1.960–1.972, 2.193–2.235, 1.461, 1.465 and 3.223–3.237 Å in I, and 2.112, 2.119, 1.957, 1,966, 2.204, 2,246, 1,467, and 3.2439 Å in II. 相似文献
13.
《Journal of Coordination Chemistry》2012,65(21):3420-3437
Two Cu(II) hydroxo succinates [Cu3(H2O)2(OH)2(C4H4O4)2]?·?4H2O (1) and [Cu4(H2O)2(OH)4(C4H4O4)2]?·?5H2O (2) and one Cu(II) hydroxo glutarate [Cu5(OH)6(C5H6O4)2]?·?4H2O (3) have been prepared and structurally characterized by single crystal X-ray diffraction methods. They feature 1D and 2D copper oxygen connectivity of elongated {CuO6} octahedra in “4?+?1?+?1” and “4?+?2” coordination geometries. Within 1, linear trimers of three edge-sharing {CuO6} octahedra are connected into copper oxygen chains, which are bridged by the anti conformational succinate anions to generate 2D layers with mono terminally coordinating gauche succinate anions on both sides. The layers are assembled into a 3D framework by interlayer hydrogen bonds with lattice H2O molecules distributed in channels. Different from 1, the principal building units in 2 are linear tetramers of four edge-sharing {CuO6} octahedra. The tetramers are condensed into copper oxygen chains and the succinate anions interlink them into a 3D framework with triangular channels filled by lattice H2O molecules. The {CuO6} octahedra in 3 are edge-shared to form unprecedented 2D inorganic layers with mono terminally coordinating glutarate anions on both sides. Interlayer hydrogen bonding interactions are responsible for supramolecular assembly of the layers into a 3D framework with lattice H2O molecules in the channels. The inorganic layers in 3 can be described as hexagonal close packing of oxygen atoms with the Cu atoms in the octahedral cavities. The title compounds were further characterized by elemental analyses, IR spectra and thermal analyses. 相似文献
14.
G. K. Fukin L. N. Zakharov G. A. Domrachev A. Yu. Fedorov S. N. Zaburdyaeva V. A. Dodonov 《Russian Chemical Bulletin》1999,48(9):1722-1732
One-pot oxidation of R3Sb (R=Ph, Me, Cl, or C6F5) withtert-butyl hydroperoxide in the presence of 1,2-diols and monodentate donor compounds was studied. The structures of the resulting neutral organic donor-acceptor SbV complexes, Ph3(C6H4O2)Sb…OSMe2, Ph3(C6H4O2)Sb…ONC5H5, Me3(C6H4O2)Sb…ONC5H5, Me3(C6H4O2)Sb…NC5H5, Ph3(C2H4O2)Sb…ONC5H5, and Cl(C6F5)2(C2H4O2)Sb…OPPh3, were established by X-ray diffraction analysis. In these complexes, the coordination environment about the Sb atoms is a distorted octahedron. The Sb?O(N) distances and the Sb?O?E angles (E=S, N, or P) vary over wide ranges. 相似文献
15.
Dr. Alain Carpy Jean -Michel Léger Danielle Roche Michel P. Madesclaire Pascale Besse Henri Veschambre 《Structural chemistry》1995,6(3):191-195
The X-ray crystal structures of (–)-syn-4-phenyl-3-bromo-2-butyl camphanate (I) and (+-anti-4-phenyl-3-bromo-2-butyl camphanate (II) have been determined. Thesyn diastereoisomer of bromohydrin has the (2S,3S) absolute configuration whereas theanti diastereoisomer has the (2S,3R) absolute configuration. The crystallized derivatives I and II have been obtained by the reaction of each stereoisomer of bromohydrin, synthesized by reduction with baker's yeast, with (1S)-camphanic chloride. Crystal data: (I) C20H25BrO4:M
w: 409.32; orthorhombic,P212121;a=11.245(3),b=12.086(1),c=14.512(4) å; Z=4; finalR=0.053 for 1819 observed reflections. (II) C20H25BrO4;M
w=409.32; monoclinic, P21;a=11.352(1),b=6.378(1),c=14.255(2) å,=110.38(1);Z=2; finalR=0.045 for 1672 observed reflections. 相似文献
16.
Sharutin V. V. Egorova I. V. Ivanenko T. K. Sharutina O. K. Pushilin M. A. Gerasimenko A. V. Adonin N. A. Starichenko V. F. 《Russian Journal of Coordination Chemistry》2004,30(5):309-313
Bismuth tris(3-methylbenzoate) [Bi(O2CC6H4CH3-3)3] (I) and phenylbismuth bis(3,4,5-trifluorobenzoate) [PhBi(-O2CC6H2F3-3,4,5)(O2CC6H2F3-3,4,5)]2 (II) were synthesized by reacting triphenylbismuth with 3-methylbenzoic and 3,4,5-trifluorobenzoic acids. Coordination numbers of bismuth atoms in I and II are 9 and 6, respectively; carboxylate ligands function as bi- and tridentate ligands. The Bi-O distances in compound I vary in the range of 2.218(3)-3.202(4) Å. The Bi-O and Bi-C bond lengths in II are 2.301(2)-2.674(2) and 2.223(3) Å, respectively. 相似文献
17.
Hanhua Zhao Curtis P. Berlinguette John Bacsa Shane E. Tichy Kim R. Dunbar 《Journal of Cluster Science》2003,14(3):235-252
The preparation and characterization of two new mixed-valence, trinuclear species, [Mn3O(O2CCF3)6(H2O)3]CF3COOH4/3H2O (1) and [Mn3O(O2CCF3)6(CH3COOH)3] (2), is reported. Compound 1 crystallizes in the triclinic space group, P¯1 (No. 2), with the parameters, a=12.3131(9) Å, b=12.4427(9) Å, c=12.965(1) Å, =72.593(4)°, =73.453(5)°, =68.345(4)°, V=1727.2(2) Å3, and Z=2. A total of 14060 reflections were collected in the range 1.6827.52°. The final weighted and non-weighted agreement indices, R1=0.0589 and wR2=0.1445 were based on a total of 6953 unique reflections with an R
int value of 0.0542. Compound 2 crystallizes in the monoclinic space group, P21/n (No. 14), with the parameters, a=12.876(3) Å, b=12.212(4) Å, c=17.732(4) Å, =100.40(3)°, V=3640.4(1) Å3, and Z=4. A total of 32197 reflections were collected in the range 1.7227.13°. The final weighted and non-weighted agreement factors, R1=0.0647 and wR2=0.1609 were based on a total of 8018 unique reflections with an R
int
value of 0.0462. An investigation of the physical properties revealed that both compounds display an intermediate ground state of S=3/2 as a consequence of intramolecular antiferromagnetic coupling. The magnetic data for compound 1 was best fit to the parameters g=2.09, J=–5.5 cm–1, J=–3.4 cm–1, and D
Mn(III)=–4.5 cm–1; the data for compound 2 was best fit to the parameters g=2.10, J=–2.9 cm–1, J=–5.5 cm–1, and D
Mn(III)=–4.5 cm–1. 相似文献
18.
The preparation and structural characterization of two trinuclear vanadium complexes, (V(3)(μ(3)-O)O(2))(μ(2)-O(2)P(CH(2)C(6)H(5))(2))(6)(H(2)O), 1, and (V(3)(μ(3)-O)O(2))(μ(2)-O(2)P(CH(2)C(6)H(5))(2))(6)(py), 2, are reported. In these nonclassical structures, the planar central core consists of the three vanadium atoms arranged in the form of an acute quasi-isosceles triangle with the central oxygen atom multiply bonded to the vanadium atom at the center of the vertex angle and weakly interacting with the two other vanadium atoms on the base sites, each of which contain one external multiply bonded oxygen atom. Reacting VO(acac)(2)in the presence of diphenylphosphinic acid affords (VO(O(2)PPh(2))(2))(∞), 3, while 2-hydroxyisophosphindoline-2-oxide at room temperature in CH(2)Cl(2) affords ((H(2)O)VO(O(2)Po-(CH(2))(2)C(6)H(4))(2))(∞), 4, and at 120 °C in EtOH yields (VO(O(2)P(o-(CH(2))(2)(C(6)H(4)))(∞), 5 on the basis of elemental analyses. The thermal and chemical stability of the complexes were assessed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) measurements. The bond strengths of the vanadium atoms to the OH(2) ligand in 1 and to the NC(5)H(5) ligand in 2 were assessed at 10.7 and 42.0 kJ/mol respectively. Room temperature magnetic susceptibility measurements reveal magnetic moments for trinuclear 1 and 2 at 3.02(1) and 3.05(1) μ(B/mol), and also close to spin only values (1.73 μ(B)) values for 3, 4, and 5 at 1.77(2), 1.758(7), and 1.77(3) μ(B), respectively. Variable-temperature, solid-state magnetic susceptibility measurements were conducted on complex 2 in the temperature range of 2.0-298 K and at an applied field of 0.5 T. Magnetization measurements at 2 and 4 K confirmed a very weak magnetic interaction between the vanadyl centers. 相似文献
19.
Christe KO Haiges R Boatz JA Jenkins HD Garner EB Dixon DA 《Inorganic chemistry》2011,50(8):3752-3756
A recent crystallographic study has shown that, in the solid state, P(C(6)H(5))(4)N(3) and As(C(6)H(5))(4)N(3) have ionic [M(C(6)H(5))(4)](+)N(3)(-)-type structures, whereas Sb(C(6)H(5))(4)N(3) exists as a pentacoordinated covalent solid. Using the results from density functional theory, lattice energy (VBT) calculations, sublimation energy estimates, and Born-Fajans-Haber cycles, it is shown that the maximum coordination numbers of the central atom M, the lattice energies of the ionic solids, and the sublimation energies of the covalent solids have no or little influence on the nature of the solids. Unexpectedly, the main factor determining whether the covalent or ionic structures are energetically favored is the first ionization potential of [M(C(6)H(5))(4)]. The calculations show that at ambient temperature the ionic structure is favored for P(C(6)H(5))(4)N(3) and the covalent structures are favored for Sb(C(6)H(5))(4)N(3) and Bi(C(6)H(5))(4)N(3), while As(C(6)H(5))(4)N(3) presents a borderline case. 相似文献
20.
S. P. Khranenko E. A. Bykova K. V. Yusenko A. P. Tyutyunnik S. A. Gromilov 《Journal of Structural Chemistry》2013,54(5):931-936
X-ray crystallographic analysis is used to determine the crystal structures of [Ru(NH3)6](MoO4)Cl·3H2O and [M(NH3)6](ReO4)3·2H2O (M = Ru, Ir) complex salts. The features of the fragment packing are studied. 相似文献