bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Schiff Base‐type Liquid Crystalline Crown Ethers Containing Dibenzo‐18‐Crown‐6 Unit
Authors: Zhang Shu‐Yuan , He Ke‐Ke , Zheng Shi‐Jun , Tang Si‐Fu , Zhang Xiao‐Jing , Li Zi‐Fa
Published: September 2010

The synthesis and characterization of novel Schiff base liquid crystalline crown ethers prepared from the intermediates 4‐(4′‐alkoxylbiphenyl‐4‐carbonyl) benzaldehyde, cis‐ and trans‐4,4′‐diaminodibenzo‐18‐crown‐6 are described. The structure of these compounds have been well characterized by elemental analysis, IR, 1H NMR and MS spectroscopy. The liquid‐crystalline behavior of these compounds was also investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) with a heating stage and polarimetric analysis.
Synthesis, Spectroscopic Properties and Crystal Structures of Dibenzyltin(IV)‐Dithiobenzoate and Chlorodibenzyltin(IV) Thiobenzoate
Authors: Yin Han‐Dong , Wang Chuan‐Hua , Ma Chun‐Lin , Fang Hai‐Xa
Published: September 2010

Two dibenzyltin(IV) complexes with thiobenzoate ligand, (PhCH2)2Sn(SOCPh)2 (1) and (PhCH2)Sn(Cl)SOCPh (2), have been synthesized by the reaction of dibenzyltin(IV) dichloride with thiobenzoic acid in the presence of organic base Et3N and characterized by IR, 1H NMR spectroscopy and elemental analysis. Their crystal structures were determined by X‐ray single crystal diffraction analysis. In the crystals of 1, the tin atom is six‐coordinated in a distorted octahedron configuration. In the crystals of 2, the molecular packing in unit cell reveals that the two adjacent molecules are symmetrically linked to each other to form a dimer with intermolecular Sn…Cl distances of 0.3591(2) nm and the tin atom is five‐coordinated in a distorted trigonal bipyramid configuration.
Homocoupling of aryl iodides catalyzed by cyclopalladated complexes of tertiary arylamines
Authors: Li Qiang , Nie Juan , Yang Fan , Zheng Rui , Zou Gang , Tang Jie
Published: September 2010

Homocoupling of aryl iodides catalyzed by cyclopalladated complexes of tertiary arylamines gives symmetric biaryls with good yields in DMA or ionic liquid [Bmim]BF4. This catalytic alternative of the Ullmann reaction has proved to be sensitive to both electronic and steric factors of substrates.
Density functional theory and MP2 calculations of the transition states and reaction paths on coupling reaction of methane through plasma
Authors: Yang En‐Cui , Zhao Xiao‐Jun , Tian Peng , Hao Jin‐Ku
Published: September 2010

The two possible reaction paths of producing ethane on coupling reaction of methane through plasma were theoretically investigated by B3LYP and MPF2 methods with 6‐311G* respectively and further compared with the previous results calculated from B3LYP/6‐31G*. The new investigated results consistently confirmed the previous conclusion. And the influences of the calculation methods and basis sets on the calculated results were also discussed.
Synthesis, crystal structures and characterization of Ba5LiTiNb9O30
Authors: Liu Han‐Xing , Zou Long , Zhou Jian , Fang Liang , Zhang Gao‐Ke , Ouyang Shi‐Xi
Published: September 2010

A new niobate compound with the chemical composition of Ba5LiTiNb9O30 was synthesized by doping Li+ into the system BaO‐TiO2‐Nb2O5 in conventional solid state reaction method. The crystalline structure was determined by X‐ray dilation analysis (XRD). The results showed that crystal structure of Ba5LiTiNb9O30 belongs to tetragonal tungsten bronze structure with space group P4bm and its unit cell parameters: a=b= 1.2512(2) nm, c= 0.4008(5) nm. The microstructure of reaction products was observed by scanning electron microscopy (SEM).
Spectrofluorimetric determination of reduced glutathione using organic nanoparticle probes
Authors: Wang Le‐Yu , Wang Lun , Zhu Chang‐Qing , Dong Ling , Xia Ting‐Ting , Chen Hong‐Qi , Bian Gui‐Rong
Published: September 2010

Nanometer‐sized fluorescent particles (poly‐4‐vinylaniline nanoparticles) have been prepared under ultrasonic radiation. The fluorescence of poly‐4‐vinylaniline nanoparticles (PVN) is ca. 50 folds higher than that of 4‐vinylaniline. In comparison with single organic fluorophores, these nanoparticle probes are brighter, more stable against photobleaching, and do not suffer from blinking of light emission. A new fluorimetric method for the determination of reduced glutathione (GSH) has been developed with poly‐4‐vinylaniline nanoparticles as a probe. The maximal fluorescence for the reagent occurs at excitation and emission wavelengths of 306 and 380 nm, respectively. Under optimal conditions, PVN reacts with GSH and o‐phthalaldehyde (OPA) to give a highly fluorescent derivative in Na2CO3‐HCl buffer (pH= 10.55). The fluorescence excitation and emission wavelengths of the fluorescent derivative are located at 340 and 428 nm, respectively. The relative fluorescence intensity (RF) is linear in the range of the GSH concentration from 3.0 × 10−7 to 1.2 × 10−5 mol/L. The method has been applied to the determination of GSH in synthetic samples with satisfactory results.
Novel Rearrangement of Small Peptides in Electrospray Ionization Tandem Mass Spectrometry
Authors: Chen Yi , Wang Jin , Liu Xiao‐Hong , Sun Ming , Chen Jing , Jiang Yang , Zhao Yu‐Fen
Published: September 2010

Electrospray ionization mass spectrometry (ESI‐MS) is a powerful method for sequencing peptides. A novel fragmentation pattern with the loss of a neutral fragment of 45 Da was observed with the dipeptides, tripeptides, tetrapeptides and pentapeptides containing phenylalanine or histidine residues. A novel rearrangement reaction with the extrusion of a formamide piece was studied and the rearrangement mechanism was proposed and confirmed by deuterium labeling experiments with ESI‐MS and high‐resolution mass spectrometry. These findings are potentially helpful in identifying the specific sequence pattern in the peptide sequencing.
Synthesis of Glutamic Acid‐based Cluster Galactosides and their Binding Affinities with Liver Cells
Authors: Zhang Xiao‐Ru , Li Ylng‐Xia , Chu Shi‐Dong , Ding Ning , Li Chun‐Xia , Guan Hua‐Shi
Published: September 2010

Structurally well defined di‐, tri‐ and tetra‐valent cluster galactosides were synthesized in a convenient way. Oligo‐glutamic acids were assembled as scaffolds. The presence of amine groups in these three ligands is expected to couple with drugs or genes for delivery. The binding affinities of these cluster galactoses to liver cells were determined by in vitro binding studies. Among them. the tetravalent cluster galactose (19) showed the highest affinity to Liver cell. It is therefore a promising targeting device for the specific delivery of drugs or genes to parenchymal liver cells.
Studies on the Physicochemical Properties, Structure and Antitumor Activity of an Oligosaccharide Homologue SnS‐2 from the Root of Scrophularia ningpoensis Hemsl
Authors: Deng Jun‐E , Zhang Jian , Chen Xiao‐Ming , Ke Wei , Tian Geng‐Yuan
Published: September 2010

An oligosaccharide homologue named SnS‐2 was isolated from the root of Scrophularia ningpoensis Hemsl. SnS‐2 was purified by means of gel‐permeation chromatography and ion‐exchange chromatography. Its physico‐chemical properties, including carbohydrate content and molecular weight were determined. The structure of SnS‐2 was elucidated by chemical methods along with 1H and 13C NMR spectroscopy, including two‐dimensional DQCOSY and H‐detected 1H, 13C HMQC experiments. These. results show that SnS‐2 possesses a backbone consisting of terminal α‐Galp(1→, α‐Galp‐(1→6), α‐Glcp‐(1→6) and nonreducing end β‐Furf‐(2→. The bioactive assay showed that it could inhibit the growth of Lewis pulmonary carcinoma implanted in mice.
Synthesis and characterization of α‐hexadecyl‐DOTA and its Gd(III) chelate
Authors: Feng Zhi‐Ming , Li Feng , Lei Chun‐Hua , Chen Rong , Lixs Xiao‐Ru
Published: September 2010

Synthesis and characterization of the ligand. 10‐(α‐hexadecylarboxyethyl)‐1,4,7,10‐tetraazacyclododecane‐1,4,7‐triacetic acid (H4L), and its Gd(III) chelate are described. Protonation constants for H4L (lg KiH = 10.52, 9.45, 4.74, 4.10) and the stability constant for GdL− (lg KGdL‐ =24.50) were determined by potentiometric titrations. The results obtained show that the ligand still maintains the strong chelating properties of the parent DOTA (1,4,7,10‐tetraazacyclododecae‐N,N′,N′'N′‐tetraacetic acid) after introduction of a linear chain hexadecyl group at the acetic side chain of DOTA, and its basicity is not significantly altered.
Quantum chemical study on a new mechanism of one‐carbon unit transfer reaction: The water‐assisted mechanism
Authors: Qiao Qing‐An , Cai Zheng‐Ting , Feng Da‐Cheng
Published: September 2010

It is a theoretical study on the water‐assisted mechanism of one‐carbon unit transfer reaction, in which the energy barrier for each aansition state lowered by about 80‐1100 kJ/mol when compared with the one in no‐water‐involved mechanism. The water‐assisted path 4 is the favorite reaction way. Our results well explained the presumption from experiments.
Studies on the adsorption of asymmetrical triblock copolymers by scheutjens‐fleer theory and monte carlo simulation
Authors: Peng Chang‐Jun , Li Jian‐Kang , Liu Hong‐Lai , Hu Ying
Published: September 2010

The adsorption of asymmetrical triblock copolymers from a non‐selective solvent on solid surface has been studied by using Scheutjens‐Fleer mean‐field theory and Monte Carlo simulation method on lattice model. The main aim of this paper is to provide detailed computer simulation data, taking A8‐kB20Ak as a key example, to study the influence of the structure of copolymer on adsorption behavior and make a comparison between MC and SF results. The simulated results show that the size distribution of various configurations and density‐profile are dependent on molecular structure and adsorption energy. The molecular structure will lead to diversity of adsorption behavior. This discrepancy between different structures would be enlarged for the surface coverage and adsorption amount with increasing of the adsorption energy. The surface coverage and the adsorption amount as well as the bound fraction will become larger as symmetry of the molecular structure becomes gradually worse. The adsorption layer becomes thicker with increasing of symmetry of the molecule when adsorption energy is smaller but it becomes thinner when adsorption energy is higher. It is shown that SF theory can reproduce the adsorption behavior of asymmetrical triblock copolymers. However, systematic discrepancy between the theory and simulation still exists. The approximations inherited in the mean‐filed theory such as random mixing and the allowance of direct back folding may be responsible for those deviations.
A three‐dimensional heteronuclear polymer of [Ag2Fe(SCN)5‐(DMF)]n containing channels and one‐dimensional Ag2S2‐S‐Ag2S2 chains with Ag…Ag interaction
Authors: Li Xiu‐Ling , Zhao Chang‐Chun , Chen Jiu‐Tong , Du Wen‐Xin
Published: September 2010

The Ag2S2 rings connect [Fe(NCS)5(DMF)]2‐ (DMF=N,N‐dimethylformamide) octahedrons by bridging thiocyanates leading to a 3‐D [Ag2Fe(SCN)5(DMF)]n framework. The Fe(III) atoms are in the octahedral geometry and Ag(1) atoms are in the distoned tetrahedral geometry. One‐dimensional Ag2S2‐S‐Ag2S2 wave‐like strand chains along the b‐axis and channels constructed from ten‐membered Ag2Fe(SCN)2S rings along the c‐axis feature the three‐dimensional framework. The Ag…Ag distance of 0.3103(1) nrn in Ag2S2 rings indicates weak Ag…Ag interaction. Such an Ag2S2‐S‐Ag2S2 chain in silver(I) complexes is unprecedented. Crystal data: M,=635.09, ortho‐rhombic, Pnma, a= 1.64214(13) nm, b= 1.40075(11) nm, c=0.84445(7) nm, V=1.9424(3) nm3, Z=4, μ(Mo Kα) =3.278 mm−1, Dcaled=2.172g × cm−3. F(000)= 1220, R1=0.0443, wR2=0.1138.
Structure of AcMet‐Gly and its interaction with palladium(II) tetraaqua complex studied by electrospray mass spectrometry and density functional theory
Authors: Jin Chen , Zhang Lin , Hong Jin , Yang Gao‐Sheng , Zhu Long‐Gen
Published: September 2010

The structure of dipepide AcMet‐Gly was determined by X‐ray crystallographic analysis. It possesses mono‐clinic, space group P21 (No. 4). with cell dimensions of α=0.8571(2) nm, b=0.5871(2) nm, c= 1.197(3) nm, β= 99.290(10)°. V=0.5944(15) nm3, Z=2, μ=2.74 cm−1. Mononuclear chelates, described as [Pd(X)(S,N,O‐AcMet‐Gly)]−, in which Pd(II) is coordinated by thioether, deprotonated amide nitrogen, carbonyl oxygen of me‐thionine and X (AcMetGly or other ligands present in aqueous solution or in mobile phase solution), were detected 5 min after mixing AcMet‐Gly with [Pd(H2O)4]2‐ at room temperature using electrospray ionization mass spectrometry. The geometry of [Pd(H2O)(S,N,O‐AcMet‐Gly)]− is optimized at density functional B3LYP/LanL2DZ level. The fused five‐ and six‐membered chelate is responsible for cleavage of Met‐Gly bond. This is the first time to provide a direct evidence for Pd(II)‐mediated cleavage of dipeptides via external solvent attack.
Cobalt(II) salen complex with two aza‐crown pendants and its analogues as synthetic oxygen carriers
Authors: Wei Xing‐Yue , Li Jian‐Zhang , Mao Zhi‐Hua , Zhou Bo , Qin Sheng‐Yingtn
Published: September 2010

Salen with two aza‐crown ether pendants H2L1 and its analogues H2L2‐H2L4 were successfully synthesized starting from benzo‐10‐aza‐15crown‐5 (BN15C5) or morpholine. Their structures were characterized by IR, MS, 1H NMR and elemental analysis, and were confirmed by X‐ray diffraction analysis of H2L1. Moreover, the saturated oxygen uptake of their cobalt(II) complexes CoL1‐CoL4 in diethyleneglycol dimethyl ether was determined at different temperature. The oxygenation contants (KO2 ) and thermodynamic parameters (ΔH° and ΔS°) were calculated. The modulation of O2‐binding capabilities by pendant substituents were investigated as compared with the parent Schiff base complex CoL5 (CoSalen). The results indicate that the dioxygen affinities of CoL have been much more enhanced by aza‐crown pendants than that by morpholino pendants, and the O2‐binding capabilities of CoL1 and CoL2 with aza‐crown pendants would also be enhanced by adding alkali metal cations.
Synthesis, characterization and application of benzyl‐substituted cyclopentadienyl lanthanide complexes as catalyst precursors for the syndiotactic polymerization of methyl methacrylate
Authors: Qian Yan‐Long , Baia Muhammad , Xie Xiao‐Min D. , Huang Ji‐Ling
Published: September 2010

Benzyl‐substituted cyclopentadienyl lanthanide complexes were synthesized and characterized by elemental analysis, MS and IR spectroscopy. The analytical data point out the formation of monomeric. unsolvated complexes. In conjunction with AI(Et)3as co‐catalyst. the title complexes are efficient catalysts for the syndiotactic polymerization of methyl methacrylate. For the complex (C6H5CH2C5H4)2YCl, under the optimum polymerization conditions (60 °C,n(MMA) :n(catalyst) :n(co‐catalyst)=1000 : 1 : 10), a predominantly syndiotactic (rr=66%) polymer of high molecular weight (Mn=105000) was obtained.
Syntheses of some new group 4 non‐Cp complexes bearing schiff‐base, thiophene diamide ligands respectively and their catalytic activities for α‐olefin polymerization
Authors: Huang Ji‐Ling , Lian Bing , Yong Li , Qian Yan‐Long
Published: September 2010

Totally sixteen new titanium and zirconium non‐Cp complexes supported by Schiff‐base, or thiophene diamide ligands have been synthesized. The complexes are obtained by the reaction of M(OPT‐i)4 (M=Ti, Zr) with the corresponding Schiff‐base ligand in 1: 1 molar ratio in good yield. The thiophene diamide titanium complex has been prepared from trimethylsilyl amine [N,S,N] ligand and TiCl4 in toluene at 120 °C. All complexes are well characterized by 1H NMR, IR, MS and elemental analysis. When activated by excess methylaluminoxane (MAO), complexes show moderate catalytic activity for ethylene polymerization, and complex 1f (R1=CH3, R2=Br) exhibits the highest activity for ethylene and styrene polymerization. When the complexes were preactivated by triethylaluminum (TEA), both polymerization activities and syndiotacticity of the polymers were greatly improved.
Synthesis of N‐squaramidoacids and their application in asymmetric borane reduction of prochiral ketones
Authors: Zhang Ji , Li Lei‐Lei , Zou Hai‐Hua , Chen Jun‐Jun , Yu Kai‐Bei , Xie Ru‐Gang
Published: September 2010

A series of novel N‐squaramidoacid ligands were prepared conveniently. Without converting to corresponding amino alcohols, these ligands could be used in asymmetric borane reduction of prochiral aromatic ketones to give secondary alcohols in good to excellent enantiomeric excesses. The results showed that N‐squaramidoacids are more efficient ligands than N‐sulfonyl amino acids. N‐Squaryl proline was proved to be an excellent ligand in this catalytic asymmetric process.
Novel efficient light‐emitting polyfluorene derivatives modified by electron‐deficient moieties with nonlinear structure
Authors: Peng Qiang , Huang Yan , Lu Zhi‐Yun , Qin Sheng‐Ying , Xie Ming‐Gui , Gao Wei‐Xian , Peng Jun‐Biao , Cao Yong
Published: September 2010

Two novel fluorene‐based copolymers (PFSD and PFMD) containing squaric acid or maleimide unit in the main chain were synthesized in good yields by Suzuki coupling reaction. The resulting polymers possess excellent thermal stability, high electron affinity and high photoluminescence (PL) quantum yields. They can fluoresce in yellow‐light range due to either the charge transfer between a fluorene segment and an electron‐deficient containing squaric acid/maleimide segment of the polymers or the Forster energy transfer between different polymer chains. The results from PL measurements of the isothermally heated polymer thin films show that the commonly observed aggregate excimer formation in polyfluorenes is very effectively suppressed in these two polymers due to the nonlinear structures of maleimide and squaric acid moieties. Double‐layer polymer light‐emitting diodes (PLED) were fabricated using the resulting polymers as the emitting layers and Ba or Mg : Ag (V : V= 10 : 1) as cathodes. All the devices show bright yellow emission (562‐579 nm) with different maximum external quantum efficiencies (0.006%‐1.13%). Compared with the other devices, indium‐tin oxide (ITO)/polyethylenedioxythiophene (PEDOT) : polystyrene sulfonic acid (PSS)PFMD/Mg : Ag has the higher maximum external quantum efficiency of 1.13% at 564 cd/m2 with a bias of 8.4 V.
Peripheries of molecular projection in three‐dimensional space and studies of quantitative structure‐activity relationships
Authors: Zhang Qing‐You , Luo Cao‐Cao , Qi Yu‐Hua , Dong Lin , Wang Jun , Xu Lu
Published: September 2010

A new index, i.e., the periphery representation of the projection of a molecule from 3D space to a 2D plane is described. The results, correlation with toxicity of substituted nitrobenzenes, obtained by using periphery descriptors are much better than that obtained by using the areas (i.e., shadows) of projections of the compounds. Even better results were achieved by using the combination of periphery descriptors and the projections areas as well as the indicated variable K reflecting the action of group NO2 position on the benzene ring.
Quantum chemical study on the reaction mechanism of OBrO radical with OH radical
Authors: Zhao Min , Zhao Yan‐Ling , Liu Peng‐Jun , Chang Ying‐Fei , Pan Xiu‐Mei , Su Zhong‐Min , Wang Rong‐Shun
Published: September 2010

The reaction mechanism of OBrO with OH has been studied using the B3LYP/6‐311+G(d,p) and the high‐level electron‐correlation CCSD(T)/6‐311+G(d,p) at single‐point. The results show that the title reaction could probably proceed by four possible schemes, generating HOBr+O2, HBr+O3, BrO+HO2 and HOBrO2 products, respectively. The main channel is the one to yield HOBr + O2. The whole reaction involves the formation of three‐membered, four‐membered and five‐membered rings, followed by the complicated processes of association, H‐shift, Br‐shift and dissociation. All routes are exothermic.
Molecular design of crown ethers. 22. Synthesis of benzocrown ether derivatives and their solvent extraction with univalent/bivalent metal picrates
Authors: Yang Ying‐Wei , Li Chun‐Ju , Zhang Heng‐Yi , Liu Yu
Published: September 2010

Three novel benzocrown ether derivatives have been synthesized and their cation binding behavior with uni‐and bi‐valent metal ions was evaluated by the solvent extraction of aqueous metal picrates. The obtained results indicate that the size‐fit of crown ether and metal cation, and electron effect of the side arm attached to benzocrown ethers affect their cation binding ability and selectivity.
Study on osmotic pressure and liquid‐liquid equilibria for micelle, colloid and microemulsion systems by Yukawa potential
Authors: Fu Dong , Lu Jiu‐Fang , Wu Wei , Li Yi‐Gui
Published: September 2010

An equation of state (EOS) was established to study the osmotic pressure and liquid‐liquid equilibria for micelle, colloid and microemulsion systems. The Carnahan‐Starling equation was used for the hard sphere repulsion. The Yukawa potential was used to describe both the attractive dispersion and the double‐layer repulsion. By using the established EOS, the osmotic pressures for charged colloid, uncharged micelle, uncharged and weakly charged microemulsion, the phase equilibria for uncharged micelle and charged colloid systems were studied.
Synthesis, crystal structure and magnetic properties of a new 30 cobalt vanadate
Authors: Wang Lei , Zhang Hong , Zhang Jing‐Ping , Niu Ben , Cui Shu‐Xin
Published: September 2010

A new cobalt vanadate compound 1 [Co11(H2O)2 V V2 O6] has been hydrothermally synthesized and characterized by the elemental analyses and the single crystal X‐ray diffraction analysis. Compound 1 crystallizes in the orthorhombic system, space group Pmna, with a=0.55646, b= 1.06900, c= 1.18452 nm, and Z=4. The magnetic susceptibility of the cobalt vanadate has been measured and indicates possible antiferromagnetic coupling between adjacent cobalt (II) (0.5432‐0.5697 nm) through bond or space.
Kinetics and mechanism of the exothermic first‐stage decomposition reaction of dinitroglycoluril
Authors: Zhao Feng‐Qi , Rong‐Zu Hu , Chen Pei , Luo Yang , Gao Sheng‐Li , Song Ji‐Rong , Shi Qi‐Zhen
Published: September 2010

Under linear temperature increase condition, the thermal behavior, mechanism and kinetic parameters of the exothermic decomposition reaction of the title compound have been studied by means of DSC and IR. The initial stage of the mechanism was proposed. The empirical kinetic model function in differential form, apparent activation energy and pre‐exponential constant of the exothermic decomposition reaction are a 0.526, 207.0 kJ·mol−1 and 1018.49s‐1, respectively. The critical temperature of thermal explosion of the compound is 252.87 °C. The values of ΔS≠, ΔH≠ and ΔG≠ of the reaction are 128.4 J·mol‐1.K−1, 218.9 kJ·mol−1 and 152.7 kJ·mol−1, respectively.
Thermal Behavior of N,N'‐Bis[N‐(2,2,2‐trinitroethyl)‐N‐nitro]ethylenediamine
Authors: Chen San‐Ping , Hu Rong‐Zu , Song Ji‐Rong , Yang De‐Suo , Gao Sheng‐Li , Shi Qi‐Zhen
Published: September 2010

The thermal behavior and kinetic parameters of the exothermic decomposition reaction of N‐N‐bis[N‐(2,2,2‐tri‐nitroethyl)‐N‐nitro]ethylenediamine in a temperature‐programmed mode have been investigated by means of differential scanning calorimetry (DSC). The results show that kinetic model function in differential form, apparent activation energy Ea and pre‐exponential factor A of this reaction are 3(1 ‐α)2/3, 203.67 kJ·mol−1 and 1020.61s−1, respectively. The critical temperature of thermal explosion of the compound is 182.2 °C. The values of ΔS≠ ΔH≠ and ΔG≠ of this reaction are 143.3 J·mol−1·K−1, 199.5 kJ·mol−1 and 135.5 kJ·mol−1, respectively.
Synthesis and crystal structure of a decanuclear silver(I)‐thiolate compound Ag10S[S2P(OEt)2]8
Authors: Zhu Yong‐Bao , Lu Shao‐Fang , Huang Xiao‐Ying , Huang Zi‐Xiang , Wu Qiang‐Jin
Published: September 2010

A new decanuclear silver(I) compound Ag10(μ8‐S)(dtp)8 [dtp=S2P(OEt)2] was isolated from a reaction mixture containing W2S4(dtp)2 and AgN03, and its solid‐state molecular structure was determinated by X‐ray crystallography. The crystallographic study revealed that the compound contains a distorted mono‐capped quasi‐prism [Agio] with an octat‐bridging S atom at the center of the prism. The compound (C32H80Ag10O16P8S17, Mr=2592.46) crystallizes in the monoclinic P21/n space group, with a = 1.5111(5) nm, b=2.3656(8) nm, c=2.284(1) nm, β= 96.88(3)°, V=8.107(5) nm3, Z=4 and D,=2.12 g · cm−3. The solution using direct method and full‐matrix least‐squares refinement led to R=0.066, Rw=0.078 for 3928 reflections with I3σ(I).
Novel quasi‐solid‐state dye‐sensitized solar cell based on monolayer capped TiO2 nanoparticles framework materials
Authors: Xia Jiang‐Bin , Li Fu‐You , Huang Chun‐Hui
Published: September 2010

Dodecylbenzenesulfonate (DBS)‐capped TiO2 nanoparticles have been synthesized and employed in dye‐sensitized solar cells to form a quasi‐solid state electrolyte. Owing to the long alkyl‐chain capping around the TiO2 nanoparticles interacting with the liquid solvent, the dye sensitized solar cell based on such DBS‐capped TiO2 nanoparticle framework material gel electrolyte shows higher stability compared with the non‐capped one in the long‐term application and gives a comparable overall efficiency of 6.3% at AM 1.5 illumination.
Bismuth(III) Complexes withN,N‐Di(2‐hydroxylethyl)aminodithiocarboxylate: Synthesis and Crystal Structure of {Bi[S2CN(C2H4OH)2]2[1, 10‐Phen]2(NO3)}·3H2O and (Bi[S2CN(C2H4OH)2]3}2
Authors: Yin Han‐Dong , Xing Qiu‐Ju , Wang Chuan‐Hua
Published: September 2010

Two novel one‐ and two‐dimensional network structure bismuth(III) complexes withN, N‐di(2‐hydroxylethyl)‐aminodithiocarboxylate, {Bi[S2CN(C2H4OH)2]2[1, 10‐Phen]2(NO3)}·3H2O (1) and (Bi[S2CN(C2H4OH)2]3)2(2) were synthesized. Their crystal and molecular structures were determined by X‐ray single crystal diffraction analysis. The crystal 1 belongs to monoclinic system with space groupC2/c, a=1.6431(7) nm, b=2.4323(10) nm, c= 1.2646(5) nm, β=126. 237(5), Z=4, V=4.076(3) nm3, Dc=1.757 Mg/m3,μ=4.598 mm−1,F(000)=2156,R=0.0211,wR=0.0369. The structure shows a distorted square antiprism configuration with eight‐coordination for the central Bi atom. The one‐dimensional chain structure was formed by H‐bonding interaction between hydroxyl group ofN, N‐di(2‐hydroxylethyl)aminodithiocarboxylate ligands and crystal water. The crystal 2 belongs to monoclinic system with space group p2(1)/c, a=1.1149(4) nm, b=2.1274(8) nrn, c=2.2107(8) nm,β=98.325(8)°, 2=4, V=5. 188(3) nm3,Dc=1.920 Mg/m3, μ=7.315 mm−1, F(000)=2944, R=0.0565,wR=0.0772. The structure shows a distorted square antiprism configuration with eight‐coordination for the central Bi atoms. The two‐dimensional network structure was formed by H‐bonding interaction between adjacent molecules.
Universal electrochemical/chemical simulator based on an exponentially expanding grid network approach
Authors: Deng Zhao‐Xiang , Lin Xiang‐Qin , Tong Zhong‐Hua
Published: September 2010

A universal simulator capable of simulating virtually any user‐defined electrochemical/chemical problems in one‐dimensional diffusion geometry was developed based on an exponentially expanding grid modification of the existing network approach. Some generalized reaction‐diffusion governing equations of an arbitrary electrochemical/chemical process were derived, and program controlled automatic generation of the corresponding PSPICE net‐list file was realized. On the basis of the above techniques, a universal simulator package was realized, which is capable of dealing with arbitrarily complex electrochemical/chemical problems with one‐dimensional diffusion geometry such as planar diffusion, spherical diffusion, cylindrical diffusion and rotational disk diffusion‐convection processes. The building of such a simulator is easy and thus it would be very convenient to have it updated for simulations of newly raised electrochemical problems.
Diastereoselective synthesis of chiral pyrrolidine and piperidine ring systems
Authors: Shao Zhi‐Hui , Peng Fang‐Zhi , Zhu Bao‐Kun , Tu Yong‐Qiang , Zhang Hong‐Bin
Published: September 2010

A diastereoselective method for the synthesis of chiral pyrrolidine and piperidine ring containing compounds was described. The protocol of bromination followed by aminocyclization furnishes an easily handled while highly efficient procedure for the intramolecular amidation of an isolated double bond. High diastereomeric excess was observed in this synthetic procedure.
Chiral and achiral bis(2‐oxazolinylphenolato)nickel(II) complexes—synthesis, crystal structure, and catalytic properties
Authors: Zhao Wei , Qian Yan‐Long , Huang Ji‐Ling
Published: September 2010

A series of chiral and achiral bis(2‐oxazolinylphenolato)nickel@) complexes 2 were synthesized by reactions of various 2‐(4, 5dihydro‐2‐oxazolyl)phenol derivatives with nickel chloride hexahydrate. The molecular structure of complex 2a was determined by X‐ray single crystal diffraction. The crystal of complex 2a was monoclinic, space group P21 with cell dimension of a= 1.1121(4) nm, b=0.9472(3) nm, c=1.4113(5) nm, α=γ=90°,β=91. 450(6)°, V=1.4861(8) nm3, Z=2, and μ=0.693 mm−1. In the solid state, the nickel(II) ion was in a square‐planar coordination geometry. The catalytic activities of complexes 2 in Baeyer‐Villiger reaction with molecular oxygen were investigated.
Preparation and characterization of a new dinuclear ruthenium complex with BDPX ligand and its catalytic hydrogenation reactions for cinnamaldehyde
Authors: Tang Yuan‐You , Li Rui‐Xiang , Li Xian‐Jun , Wong Ning‐Bew , Tin Kim‐Chung , Zhang Zhe‐Ying , Mak Thomas C. W.
Published: September 2010

A new anionic dinuclear ruthenium complex bearing 1, 2‐his(diphenylphosphinomethyl)benzene (BDPX) [NH2Et2][{RuCl (BDPX)}2(μ‐Cl)3] (1) was synthesized and its structure was determined by an X‐ray crystallo‐graphic analysis. This result indicated that complex 1 consisted of an anion dinuclear BDPX‐Ru and a cationic di‐ethylammonium. The crystal belonged to monoclinic system, C2/c space group with a=3.3552(7) nm, b= 1.8448(4) nm, c=2.4265(5) nm, β= 101.89(3)° and Z=8. The catalytic hydrogenation activities and selectivities of complex 1 for cinnamaldehyde were investigated.
First magnesium‐mediated carbonyl benzylation in water
Authors: Deng Wei , Tan Xiang‐Hui , Liu Lei , Guo Qing‐Xiang
Published: September 2010

Catalyzed by AgNO3, Mg was found for the first time to be able to mediate the coupling reaction between aromatic aldehydes and benzyl bromide or chloride in water. The yields were slightly higher than the recent results for Mg‐mediated allegation despite the fact that aqueous benzylation is intrinsically much harder than allegation. It was also found that the coupling reaction was chemoselective for aromatic aldehydes over aliphatic aldehydes, and chemoselective for aromatic aldehydes over aromatic ketones.
Isolation and structure of I‐deoxybaccatin VI from the root of taxus chinensis, rehd. var. mairei
Authors: Lin Hai‐Xia , Li Ming , Chen Jian‐Min , Chen Min‐Qin
Published: September 2010

Deoxybaccatin VI (4α,7β,9α,10β,13α‐penta‐acetoxy‐2a‐benzoyloxy‐5β,20‐epoxytax‐11‐ene) was isolated from the roots of Taxus chinensis, Rehd. var mairei. The structural assignments of the compound were based on their spectral data, including 2D NMR experiments and chemical correlation. The X‐ray crystallographic analysis of 1‐deoxybaccatin VI provided unambiguous characterization for the structures. In the structure, the six‐membered A ring exhibits boat conformation, the eight‐membered B ring adopts boat‐chair conformation, and the six‐membered C ring exhibits a sofa conformation.
Asymmetric inducing synthesis of optically active tetrahedral cluster containing SMCOW core
Authors: Zhao Quan‐Yi , Zhang Yu‐Hua , Hu Bin , Zhang Wei‐Qiang , Zhu Bao‐Hua , Yin Yuan‐Qi , Xia Chun‐Gu
Published: September 2010

The chiral clusters (μ3‐S)MCoW(CO)8[n5‐C5H4C(O)OCH3] =Ru (2), Fe (3)] were synthesized by asymmetric induction of N‐benzylcinchonium chloride as phase‐transfer catalyst (PTC). The most suitable amount of PTC is 70 mol%. Cluster 3 was determined by single crystal X‐ray diffraction analysis. The best ee of the chiral cluster is over 20%.
An improved method for the synthesis of optically active tomoxetines and fluoxetines
Authors: Xu Cheng‐Fu , Yuan Cheng‐Ye
Published: September 2010

A chemoenzymatic approach was applied to the preparation of chiral 3‐hydroxy‐3‐arylpropionates and 3‐hydroxy‐4,4,4‐trifluorobutanoate that are potential precursors for certain chiral pharmaceuticals including chiral tomoxetines and fluoxetines.
Synthesis of covalently‐linked linear donor‐acceptor copolymers containing porphyrins and oligothiophenes
Authors: Duanmu Chuan‐Song , Chen Zhang‐Ping , Yu Xue‐Song , Zhou Xiang
Published: September 2010

A series of monomers of 5,15‐dithienyl porphyrin, 5,15‐di‐bithienyl porphyrin and their metal complexes were synthesized in high yields. 5,15‐Di‐bithienyl porphyrin and its metal complexes were polymerized by chemical oxidation using FeCl3 as oxidant (>go%) for making organic conductor and the linear porphyrin‐thiophene copolymers were obtained. The structures of the copolymers were identified by elemental analysis and IR spectra. The conductivity of poly 5,15‐di‐bithienyl porphyrin was measured to reach over 10−6 S/cm. 5,15‐Dithienyl porphyrins and its metal complexes could not be polymerized under the similar conditions, but could be polymerized by electrochemical oxidation on the gold‐plate electrode.
Thermochemistry of the ternary complex Nd(Etndtc)3(phen)
Authors: Fan Xue‐Zhong , Chen San‐Ping , Gao Sheng‐Li , Jiao Bao‐Juan , Hu Rong‐Zu , Shi Qi‐Zhen
Published: September 2010

The ternary solid complex has been synthesized with sodium diethyldithiocarbamate (NaEt2dtc·3H2O), 1,10‐phenanthroline (o‐phen·H2O) and hydrated neodymium chloride in absolute ethanol. The title complex was identified as the general formula of Nd(Et2dtc)3(phen) by chemical and elemental analyses. IR spectrum of the complex showed that the Nd3+ coordinated with six sulfur atoms of three NaEt2dtc and two nitrogen atoms of o‐phen. It was assumed that the coordination number of Nd3+ is eight. The enthalpy change of liquid‐phase reaction of formation, ΔrH (1), was determined as (‐12.274±0.050) kJ·mol−1 at 298.15 K by a microcalorimeter, the enthalpy change of the solid‐phase reaction of formation, ΔrH (s), was calculated as (149.069±0.314) kJ·mol−1 on the basis of a thermochemical cycle. The thermodynamics of reaction of formation was studied by changing the temperature of liquid‐phase reaction. The constant‐volume combustion energy of the complex, ΔcU, was determined as (‐18674.22±8.33) kI·mol−1 by a precise rotating‐bomb calorimeter at 298.15 K. Its standard enthalpy of combustion, ΔcH, and standard enthalpy of formation, ΔfH, were calculated as (‐18693.43 ± 8.33) kJ·mol−1 and (‐47.03 ± 9.17) kJ·mol−1, respectively.
Influences of hard donor on cation selectivities closing to soft selenium donor in tweezer‐like calix[4]arene receptors
Authors: Liu Chang‐Yinga , Qin Da‐Bin , Leng Xue‐Bing , Chen Lang‐Xing , Zeng Xian‐Shun , Xu Feng‐Bo , Li Qing‐Shan , He Xi‐Wen , Zhang Wen‐Qin , Zhang Zheng‐Zhi
Published: September 2010

Three novel 25,27‐dihydroxy‐26,28‐bis(3‐benzylselenopropoxy)‐5,11,17,23‐tetra‐tert‐butylcdix[4]‐arene (2), 25,27‐dihydroxy‐26,28‐bis[3‐(2‐hydroxyethylseleno)propoxy]‐5,11,17,23‐tetra‐tert‐butyl‐calix[4]arene (3) and 25,27‐dihydroxy‐26,28‐bis(3‐propylselenopropoxy)‐5,11,17,23‐tetra‐tert‐butyI‐calix[4]arene (4) were synthesized for the comparison of their ion‐selectivity in ion‐selective electrodes (ISE). X‐ray structure of the CH/π complex of 4·CH2Cl2 was elucidated. ISEs based on 2‐4 as neutral ionophores were prepared, and their selectivity coefficients for Ag+ (log K) were investigated against some main group metal ions and transition metal ones using the fixed interference method (FZM). These ISEs showed excellent Ag' selectivity over most of the interfering cations examined. It is evident that the stronger Hg2+ interference may not be produced while hard donors (hydroxy) are close to the soft selenium donors.
Theoretical studies on adsorption and diffusion of hydrogen atom on Pd(311) and Ni(311) stepped surface
Authors: Wang Ze‐Xin , Zhang Xiao‐Ming , Yu Shuai‐Qin
Published: September 2010

The adsorption and diffusion of hydrogen atom on open rough Pd(311) and Ni(311) stepped surface were investigated in detail using 5‐parameter Morse Potential (5‐MP for short) method. The results on theoretical studies indicate that only threefold adsorption states exist at low coverage, and fourfold states are annihilated on the top layer which become the diffusion channels between threefold adsorption states due to strong competition and repulsion between hydrogen adatoms.
Enthalpic interaction for a‐amino acid with alkali metal halides in water
Authors: Lu Yan
Published: September 2010

The studies of the enthalpic interaction parameters, hxy, hxyy and hxyy of alkali metal halides with glycine, α‐alanine and a‐aminobutyric acid were published. Synthetic considering of the results of the studies, some interesting behaviors of the interaction between alkali metal halides and the a‐amino acids have been found. The values of hxy will increase with the increase of the number of carbon atoms in alkyl side chain of amino acid molecules and decrease with the increase of the radius of the ions. The increasing of the salt's effect on the hydrophobic hydration structure as the radii of anion is more obvious than as that of cation. The value of hxxy will regularly decrease with the increase of the number of carbon atoms in the alkyl chain of amino acids and linear increase with the increase of the radius. But the relation of hxxy with the radius of cations is not evident. The value of hxyy will increase with the increase of the radii of the ions. As the increase of the number of carbon atom of amino acids, hxyy is decreas for the ions which have lager size and there is a maximum value at α‐aniline for the ions which have small she. The behaviors of the interaction mentioned above were further discussed in view of electrostatic and structural interactions.
Theoretical study on the antioxidant activity of curcumin
Authors: Sun You‐Min , Wang Ruo‐Xi , Yuan Shi‐Ling , Lin Xian‐Jie , Liu Cheng‐Bu
Published: September 2010

The computational results for curcumin at the B3LYP/6‐31G(d,p) level show that the enol form of curcumin is more stable than the diketo form because of an intramolecular hydrogen bond, which extends the conjugation effect in the enol chain, formed in the enol structure. Cis‐diketone form can not be obtained, presumably due to the strong repulsion between the carbonyl dipoles aligned h parallel. According to the phenolic OH bond dissociation enthalpy, curcumin in its most stable form can be suggested to be a relatively good antioxidant. In order to avoid overcoming H‐bond interaction and to improve the antioxidant activity of curcumin, a catechol moiety was incorporated into curcumin for designing a novel antioxidant. It is found that the designed molecule is much more efficient to scavenge radical than curcumin, comparable to vitamin E. Moreover, the ionization potential of the designed molecule is similar to that of curcumin, indicating that the designed molecule can not display the prooxidant effect.
NMR and pattern recognition studies on the acute biochemical effects of Lu(NO3)3
Authors: Wu Hui‐Feng , Zhang Xiao‐Yu , Feng Jiang‐Hua , Sun Guo‐Ying , Wu Yi‐Jie , Pei Feng‐Kui , Nie Yu‐Xiu
Published: September 2010

Pattern recognition methods were applied to the analysis of 600 MHz1H NMR spectra of urine from rats dosed with compounds that induced organ‐specific damage in the liver and kidney. Male Wistar rats were separated into groups (n=4) and each was treated with one of following compounds: HgCl2, CCl4, Lu(NO3)3and Changle (a kind of rare earth complex mixed with La, Ce, Pr and Nd). Urine samples from the rats dosed with HgCl2, CCl4, and LU(NO3)3were collected over a 24 h time course and the samples from the rats administrated with Changle were gained after 3 months. These samples were measured by 600 MHz NMR spectroscopy. Each spectrum was data‐processed to provide 223 intensity‐related descriptors of spectra. Urine spectral data corresponding to the time intervals, 0–8 h (HgCl2and CCl4), 4–8 (Lu(NO3)3) h and 90 d (Changle) were analyzed using principal component analysis (PCA). Successful classification of the toxicity and biochemical effects of Lu(NO3)3was achieved.
Ring‐closure reaction to novel quinoline derivatives and their structural characterization
Authors: Lu Yin‐Xiang , Lan Bi‐Jian , Zhou Hui , Xu Wei , Wang Jing‐Mei , Huang Yong‐Ming
Published: September 2010

In the condensation of arylaldehydes with arylethylidenemalononitriles, it was found that, besides the normal product dienes a, the ring‐closure product quinoline derivatives b can be also obtained in 26%–50% yields. The substituent effects were also examined and a possible reaction mechanism was proposed for the formation of b. The X‐ray crystal structure of 1b confirms the structure of the ring‐closure product.
Lacunary Keggin polyoxotungstate as reaction‐controlled phase‐transfer catalyst for catalytic epoxidation of olefins
Authors: Li Ming‐Qiang , Jian Xi‐Gao , Yang Yong‐Qiang
Published: September 2010

A new reaction‐controlled phase‐transfer catalyst system, lacunary Keggin polyoxotungstate [C7H7N(CH3)3]9PW9O34 has been synthesized and used for catalytic epoxidation of olefins with H2O2 as the oxidant. Infrared spectra were used to analyze the behavior of the phase transfer of catalyst. In this system, the catalyst not only can act as homogeneous catalyst but also as heterogeneous catalyst to be easily filtered and reused. The epoxidation reaction is clean and exhibits high conversion and selectivity as well as excellent catalyst stability.
Improved synthesis of 5,5‐diamino BINAP and application to asymmetric hydrogenation
Authors: Huang Yi‐Yong , Deng Guo‐Jun , Wang Xia‐Yu , He Yan‐Mei , Fan Qing‐Hua
Published: September 2010

5,5‐Diamino BINAP has been synthesized via three steps using BINAPO as starting material with high reaction yield. Present method needed only a stoichiometric quantity of nitric acid in the step of nitration of BINAPO, giving almost quantitative reaction yield. Based on 5,5‐diamino BINAP, other three new BINAP derivatives have been synthesized. These modified BINAP ligands showed better catalytic properties as compared to BINAP itself in the asymmetric hydrogenation of 2–(6‐methoxyl‐2′‐naphthyl)acrylic acid.
Detection of hepatitis B virus DNA by duplex scorpion primer‐based PCR Assay
Authors: Kong De‐Ming , Shen Han‐Xi , Mi Huai‐Feng
Published: September 2010

The application of a new fluorogenic probe‐based PCR assay (PCR duplex scorpion primer assay) to the detection of Hepatitis B virus (HBV) DNA in human sera was described. Duplex scorpion primer is a modified variant of duplex Amplifluor, and the incorporation of a PCR stopper between probe and primer sequences improve the detection specificity and sensitivity. Combined with PCR amplification, this probe can give unambiguous positive results for the reactions initiated with more than 20 HBV molecules. In addition, the particular unimolecular probing mechanism of this probe makes the use of short target‐specific probe sequence possible, which will render this probe applicable in some specific systems.
Multianalyte biosensor for simultaneous determination of glucose and galactose based on micromachined chamber‐type electrodes
Authors: Jia Neng‐Qin , Zhang Zong‐Rang , Zhu Jiang‐Zhong , Zhang Guo‐Xiong
Published: September 2010

An amperometric multianalyte biosensor for the simultaneous determination of glucose and galactose was developed based on chamber‐type electrodes, which were fabricated by micromachining technology. The dual chamber‐type enzyme electrode with glucose and galactose sensor elements was integrated onto one microchip. The experimental parameters of this biosensor were optimized. The biosensor exhibited a linearity of up to 4.0 mol/L for glucose and 4.5 mol/L for galactose, and the response time was about 30 s for glucose and 40 s for galactose. No cross‐talking behavior was investigated in the come of simultaneous measurement of the two analytes. Interference from electroactive species, such as ascorbic acid and uric acid, was minimized due to the permselectivity of Nafion film. In addition, the biosensor displayed a storage stability of longer than one month.
Undistorted cyclic voltammograms at scan rates up to 2.5 MV.s−1 through positive feedback compensation of Ohmic drop
Authors: Guo Zhi‐Yong , Lin Xiang‐Qin , Deng Zhao‐Xiang
Published: September 2010

A circuit based on the current feedback operational amplifier was constructed to accomplish on‐line ohmic drop compensation in ultrafast cyclic voltammetry. Firstly, its characteristics were confirmed experimentally on dummy cells. Then the reduction of anthracene in acetonitrile, a classical test example with very fast electron‐transfer kinetics, was examined to prove them too. The results showed that this circuit could afford excellent ohmic drop compensation so that the undistorted voltammograms up to 2.2 MV*s−1 scan rate can be recorded, and 2.5 MV*s−1 if 5% error is tolerated.
Voltammetric behavior of sodium 7‐methoxyl‐4′‐hydroxylisoflavone‐3′‐sulfonate and its application
Authors: Zhang Zun‐Ting , Dong She‐Ying , Zheng Jian‐Bin , Zhang Hong‐Fang , Gao Hong
Published: September 2010

Voltammetric behavior of sodium 7‐methoxyl‐4′‐hydroxylisoflavone‐3′‐sulfonate (SMHS) in the aqueous solution from pH 1 to 5 was studied by linear sweep voltammetry, cyclic voltammetry and normal pulse voltammetry. Experimental results showed that in 0.2 mol*L−1 sodium citrate‐hydrochloric acid buffer solution (pH=4.65), SMHS caused only one reduction wave at −1.34 V (vs. saturated calomel electrode, SCE), which was an h‐reversible adsorptive wave of SMHS protonized involving one electron and one proton. The peak current of SMHS on linear sweep voltammogram was proportional to its concentration in the range of 8.0 × 10 −8.0·10 mol*L−1 (r = 0.995). and the detection limit was 5.0·10−‐6mol*L−1. The method was applied to determination of SMHS, in synthetic samples. In addition, its scavenging effect on superoxide anion radical was studied by the auto‐oxidation of pyrogallol in HCI‐tris buffer solution (pH = 8.2) in order to explain its peculiar biological effects. The experimental results proved that SMHS has antioxidant quality, and it is an efficient free radical scavenger of superoxide anion radical.
A new and efficient synthesis of wedelolactone derivatives
Authors: Gong Deng‐Huang , Zhang Ling , Li Jin‐Feng , Yuan Jun‐Ying , Yuan Cheng‐Ye
Published: September 2010

A new and facile method based on an intermolecular cycloaddition was described for the synthesis of wedelolactone derivatives.
Enantioselective pinacol coupling of aromatic aldehydes mediated by TiCI4(THF)2/Zn with tartaric ester
Authors: Li You‐Gui , Jiang Chen , Zhao Jun , Tian Qing‐Shan , You Tian‐Pa
Published: September 2010

Asymmetric pinacol coupling of aromatic aldehydes mediated by low valent titanium complexes of chiral ligands derived from natural tartaric acid provided corresponding pinacols in good yields with excellent diastereo‐selectivities and moderate enantioselectivities.
CuCl/Zn‐promoted Mukaiyama aldol reaction of phenyl α‐fluoro silyl enol ether with aldehydes
Authors: Zhou Ding‐Ying , Chen Umg‐Yun
Published: September 2010

2‐Fluoro‐1‐phenyl‐1‐trimethylsiloxyethene reacted efficiently with aldehydes to give α‐fluoro β‐hydroxy ke‐tones in HMPA in the presence of Zn powder and CuCl.