bluuebunny/crossref_metadata_2025_split huggingface dataset:
Supramolecular Assembly of Triangulo Pd(II) Diimine Complexes Containing Triply‐Bridging Sulfide Ligands
Authors: Tzeng Biing‐Chiau , Wu Ya‐Ling , Kuo Jau‐Huei 
Published: May 2015

AbstractWe report here a substituent effect of diimines on the solid‐state assembly of interesting triangulo Pd(II) complexes, [(Pd(d‐t‐bpy))3(μJ3‐S)2][NO3]2 1·[NO3]2 and [(Pd(bpy))3(μ3‐S)2][ClO4]2 2·[ClO4]2 (d‐t‐bpy = 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine, bpy = 2,2′‐bipyridine). 2·[ClO4]2 shows the intermolecular π···π interactions leading to the formation of one‐dimensional frameworks, whereas 1·[NO3]2 only shows the discrete structure in the solid state, featuring an interesting herring‐bone arrangement. The variation in structural motifs from 1·[NO3]2 to 2·[ClO4]2 is expected to be dominated by the substituent's steric hindrance for the diimine ligand. Thus, the crystal‐engineering approach has proved successful in the solid‐state packing due to a substituent's modification of the diimine ligand.
Preparation and Characterization of a Cobalt‐Containing Mono‐Phosphine Ligand and its Coordinated Molybdenum Complex
Authors: Huang Yi‐Luen , Wang Min‐Ging , Hong Fung‐E 
Published: May 2015

AbstractA cobalt‐containing monodentate phosphine [(μ2‐PPh2CH2PPh2‐κ2P)Co2(CO)4][μ2‐η2‐PhC≡CP(i‐Pr)2] 2f, was prepared from the reaction of (μ2‐PPh2CH2PPh2‐κ2P)Co2(CO)6 1 with PhC≡CP(i‐Pr)2. It was accompanied by an oxidized compound, [(μ2‐PPh2CH2PPh2‐κ2P)Co2(CO)4][μ2‐η2‐PhC≡CP(=O)(i‐Pr2)] 2fo during the chromatographic process. Further reaction of 2f with Mo(CO)6 resulted in the formation of a 2f‐ligated molybdenum complex 4, [(μ2‐PPh2CH2PPh2‐κ2P)Co2(CO)4][μ2‐η2‐PhC≡CP(i‐Pr2)‐κP]‐Mo(CO)5.
Sorption Studies of Nickel ions Onto Sawdust of Dalbergia Sissoo
Authors: Habib‐ur‐Rehman  , Shakirullah Mohammad , Ahmad Imtiaz , Shah Sher , Hameedullah  
Published: May 2015

AbstractSawdust of Dalbergia sissoo, a byproduct of sawmills, was found to be a promising adsorbent for the removal of nickel ions from aqueous solution. Sorption of nickel ions onto sawdust of Dalbergia sissoo was studied using the batch technique. Kinetics studies show that nickel ions sorption process obeys a first order rate law. The applicability of the Langmuir and Freundlich models for the data was tested. Both the models adequately describe the experimental data of the biosorption of nickel ions. The sorption capacities and energies were calculated. Langmuir parameters Xm and K1 were found to increase with rise in temperature; Freundlich constants 1/n and Kf have been evaluated for 293K, 303K, 313K and 323K. Thermodynamic parameter ΔH° = 4.80 kJ mol−;1 shows that sorption of nickel ions onto sawdust is an endothermic process.
A Coated Graphite Thorium‐Ion Selective Potentiometric Sensor Based on a Calix[4]arene Bearing Phosphoryl Groups
Authors: Hassanzadeh P. , Yaftian M. R. , Bahari Z. , Matt D. 
Published: May 2015

Abstract5,11,17,23‐Tetra‐tert‐butyl‐25,26,27,28‐tetrakis(diphenylphosphinoylmethoxy)calix[4]arene (1)has been used for the preparation of a graphite coated thorium ion‐selective electrode (Th4+‐ISE). The plasticized PVC membrane containing 30% PVC, 58% ortho‐nitrophenyloctylether (NPOE), 4% sodium tetraphenylborate (NaTPB) and 8% ionophore was directly coated on a graphite rod. This sensor gave good Nernstian responses with a slope of 15.5 ± 0.1 mV/decade over a concentration range of 1 × 10−5 −1 × 10−3 M of thorium ions with a limit of detection of 7.9 × 10−6 M. The dynamic response time of the electrode to achieve a steady potential was found to be about 15 seconds. The potential of the prepared sensor was independent of the pH variation in the range 2.3–4.0. The selectivity relative to several mono‐, di‐ and tri‐valent metal ions, i.e. Li+, Na+, K+, Ag+, NH4+, Sr2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, La3+, Sm3+, Dy3+, Er3+ and Y3+ was examined. This electrode can be used for 6 months without any considerable divergences in the potential response. The sensor was successfully used as an indicator electrode for the potentiometric titration of a thorium solution using a standard solution of EDTA.
Voltammetric Studies on Chromotrope 2B‐Protein Interaction and Its Analytical Application
Authors: Sun Wei , Jiao Kui , Han Jun‐Ying , Xu Gui‐Yun 
Published: May 2015

AbstractIn this paper the interaction of chromotrope 2B (Ch2B) with proteins was studied by the electrochemical method. Ch2B is an azo dye and shows irreversible electrochemical responses on the mercury electrode in a pH 3.0 Britton‐Robinson (B‐R) buffer solution. After the addition of human serum albumin (HSA) into the Ch2B solution, an interaction took place, and a supramolecular complex was formed in the mixed solution. The electrochemical parameters of the Ch2B‐HSA interaction system were calculated and compared. The results showed that in the absence and presence of HSA in Ch2B solution, the electrochemical parameters such as the formal potential E0, the electrode reaction standard rate constant ks, etc. showed no significant changes, which indicated that an electro‐inactive supramolecular biocomplex was formed. The free concentration of Ch2B in reaction solution was decreased, and this resulted in the decrease of the peak current. The binding constant and the binding ratio were calculated as 7.85 × 109 and 1:2, respectively, and the interaction mechanism was discussed. Based on the decrease of the peak current, this new electrochemical method was proposed for the determination of HSA in the concentration range of 2.0˜25.0 mg/L with the linear regression equation as ΔIp′ (nA) = 50.56C (mg/L) — 6.72 (γ = 0.995). This method was further used to determine other different kinds of proteins, such as bovine serum albumin (BSA), oval albumin, etc‥ The new method was successfully applied to detect the content of albumin in healthy human serum samples with the results in good agreement with the traditional Coomassie Brilliant Blue G‐250 spectrophotometric method.
Synthetic Approaches to Some Polymethine Asycyanine Colorants; Impact of Functional Additives & Chain Elongation on Visible Electronic Spectra
Authors: Ansari Abdus Samad , Narayan Bhupender , Kunwar Ganesh Kr. 
Published: May 2015

AbstractTwenty one new chromophoric chain β‐substituted polymethine asycyanine (CCBSPA) colorants have been synthesised by catalytic condensation of (i) 4‐dimethylaminophenylbutadientylphenyl ketone; (ii) 4‐dimethylbutadienyl‐4‐nitrophenyl ketone; and (iii) 4‐dimethylaminophenylbutadienyl‐4‐methyl‐phenyl ketone with 2‐methyl quinoline methiodide and 2‐methyl‐6‐substituted quinoline methiodides using piperidine as catalyst & ethanolic DMF as solvent.These colorants were synthesized with the object to study the impact of various functional groups and chain lengthening on visible electronic spectra. All the colorants showed increase in electronic spectra whether electron withdrawing or donating. These colorants also absorb at higher wavelengths when compared to the previously reported butadienylene chain asycyanino‐colorants.
Trichodiene Synthase: Synthesis and Inhibition Kinetics of 12‐Fluoro‐farnesylphosphonophosphate for Sesquiterpene Cyclases
Authors: Chen Yi‐Lin , Chiu Hsien‐Tai 
Published: May 2015

Abstracttrans, trans‐Farnesyl diphosphate (FPP) serves as a universal substrate for a large family of sesquiterpene cyclases that are responsible for biosynthesis of more than 300 structurally diverse sesquiterpenes in nature. A new FPP substrate analogue, 12‐fluoro‐farnesylphosphonophosphate (12‐F‐F‐CH2PP), was synthesized in this paper for applications on kinetic and mechanistic studies of the enzyme family. Trichodiene synthase (TS), a sesquiterpene cyclase, catalyzes the conversion of trans, trans‐farnesyl diphosphate (FPP) to trichodiene. 12‐F‐F‐CH2PP was tested as a potential inhibitor of TS. Inactivation and inhibition kinetic experiments showed that 12‐F‐F‐CH2PP was not a mechanism‐based inactivator for TS; instead, a mixed‐type reversible inhibition was observed with inhibition constants Ki1 = 2.33 ± 0.50 μM and Ki2 = 25.80 ± 7.70 μM, values close to those previously determined for farnesylphosphonophosphate, Ki1 = 3.25 μM and Ki2 = 9.10 μM. Although 12‐F‐F‐CH2PP did not irreversibly inactivate TS, this new analogue serves as a potential active‐site directed inactivator and mechanistic probe of other sesquiterpene cyclases and FPP‐utilizing enzymes, which utilize FPP as a common acyclic substrate.
Synthesis and Molecular Recognition of Molecularly Imprinted Polymer with Ibuprofen as Template
Authors: Hung Chin‐Yin , Huang Yun‐Tzu , Huang Han‐Hung , Hwang Ching‐Chiang 
Published: May 2015

AbstractIbuprofen and ketoprofen are chemically similar non‐steroidal anti‐inflammatory drugs widely used in the treatment of arthritis. Using a molecular imprinting technique, a simple and rapid method was developed for the simultaneous separation and determination of ibuprofen and ketoprofen. Molecular imprinting introduces artificial binding sites into a synthetic polymer matrix, allowing it to exhibit selective rebinding of template molecules. Imprinted polymers can be regarded as an HPLC stationary phase, important for pharmaceutical analysis.Most molecularly imprinted polymers (MIPs) are synthesized by free radical polymerization of functional monomers, resulting in an excess of crosslinking monomers. In this study, MIPs have been prepared with a ibuprofen template, which can form intramolecular hydrogen bonds. Methacrylic acid (MAA) and ethyleneglycol dimethacrylate (EGDMA) were used as the functional monomer and cross‐linker, respectively. Bulk polymerization was carried out at 4 °C under UV radiation. The resulting MIP was ground into 25˜44 μm particles, which were slurry‐packed into analytical columns. Template molecules were removed by methanol‐acetic acid (9:1, v/v). We evaluated the template binding performance of the MIP using HPLC, with ultraviolet (UV) detection at 234 nm. Chromatographic resolution of ibuprofen and ketoprofen on the MIPs were appraised using buffer/acetonitrile (45/55, v/v) as the mobile phase. Results show that the MIPs prepared using ibuprofen as the template had a significant molecular imprinting effect. The method was successfully applied to the separation and analysis of ibuprofen and ketoprofen in pharmaceuticals.
Synthesis of 1,3,4‐Oxadiazoles and 1,3‐Thiazolidinones Containing 1,4,5,6‐Tetrahydro‐6‐pyridazinone
Authors: Tao Jing , Cao Ling‐Hua , Wang Cai‐Fang , Wang Duo‐Zhi 
Published: May 2015

AbstractThe reaction of 1,4,5,6‐tetrahydro‐6‐pyridazinone‐3‐carboxylic acid hydrazides (1) with aromatic aldehydes afforded 1,4,5,6‐tetrahydro‐6‐pyridazinone‐3‐carbonyl aromatic aldehyde hydrazones (2a‐2g). Heterocyclic derivatives linked 1,3,4‐oxadiazole obtained by cyclocondensation of 2a‐2g with acetic anhydride in absolute ethanol, and 2a‐2g cyclized with mercaptoacetic acid in DMF in the presence of anhydrous ZnCl2 afforded the 1,3‐thiazolidinone derivatives. The structures of the new compounds were established by elemental analyses, IR, 1H NMR and MS spectral data.
Separation of Phenols from the Leaves of Toona Sinensis (Meliaceae) by Capillary Electrophoresis
Authors: Hsieh Ming‐Mu , Chen Chung‐Yi , Hsieh Shu‐Ling , Hsieh Sung‐Fei , Lee Pak‐Hing Ben , Li Cheng‐Ta , Hsieh Tian‐Jye 
Published: May 2015

AbstractA micellar electrokinetic capillary chromatography (MEKC) method, using UV detection, was developed for the determination of polyphenols in Toona sinensis (Meliaceae); the procedure involved precipitation of polyphenols from the leaves of T. sinensis using methanol. The structures can be established with fifteen compounds including methyl gallate, gallic acid, kaempferol, quercitin, quercitrin, rutin, kaempferol‐glucoside, catechin, epicatechin, stearic acid, palmitic acid, β‐sitosterol, stigmasterol, β‐sitosteryl‐glucoside, and stigmasteryl‐glucoside by spectroscopic analysis. However, there has been no investigation to quantitate the polyphenols that form T. sinensis. Thus, seven polyphenols of T. sinensis with UV absorbance, catechin (C), epicatechin (EC), methyl gallate (MG), rutin (R), gallic acid (G), quercitrin (Q), and kaempferol (K) were separated within 10 min with a 40 cm uncoated fused‐silica column, with the RSD < 3% (migration times), voltage at 15 kV using this method. On‐column detection was carried out at 254 nm. The detection limit of this method for all analytes ranged from 19.5 to 0.02 μM (RSD < 3.1%). The method provided a rapid and sensitive identification of polyphenols of interest in T. sinensis and is suitable for biological activity studies.
Synthesis of Phenanthridines by Flash Vacuum Pyrolysis of N‐benzylideneanilines
Authors: Hsu Yao‐Teng , Chou Chin‐Hsing 
Published: May 2015

AbstractSS‐FVP of N‐benzylidene‐4‐methoxyaniline (3b) and FVP of N‐benzylidene‐2‐chloroaniline (3c)at 850–950 °C yielded phenanthridine (2) and its derivatives through gas phase electroncyclization.
Photoluminescence of I‐VII Semiconductor Compounds. Sensitized Luminescence from “Deep States” Recombination in CuBr/AgBr Nanocrystals
Authors: Hwang L. C. , Wei T.H. , Hsia Y. L. , Li C. M. , Tu P. L. , Wen T. C. 
Published: May 2015

AbstractThe photoluminescence (PL) properties of CuBr and CuBr/AgBr semiconductor nanocrystals (NCs) embedded in borosilicate glasses are measured under band‐to‐band excitation by a 355‐nm Nd YAG laser. We observed emission from CuBr (peaked at 520 nm) doped glass, which is associated with deep states in CuBr NCs. We also observed the sensitized blue to orange‐red emission in CuBr/AgBr‐glass systems (peaked at 520 and 570 nm), in which the luminescence intensity of CuBr decreases with increasing AgBr concentrations, while it is enhanced significantly around 570 nm. The results are discussed by the possible energy transfer between them, or by the multi‐exitonic recombination process which ejects an excited carrier from CuBr to AgBr NCs.
Computational Studies on Insertion Reaction of Germynes
Authors: Cheng Mu‐Jeng , Cheng Hsin‐Mei , Chu San‐Yan 
Published: May 2015

AbstractThis paper describes theoretical studies on the insertion reaction of germynes XC ≡ GeY (X,Y=H, Cl and F) at the carbon site into a C‐H bond of CH4 performed at the QCISD(T)/6–311G*//QCISD/6–31G* level of theory. This work was inspired by the observation by Sakamoto, Kira, and coworkers on the carbene‐like reaction mode for stannyne (RC≡SnR′). Due to the limitation in the computation for the tin atom, the study was carried out on germyne compounds instead. We found that the valence state of the germyne moiety in the transition state and reaction product can be well represented by the triplet germyne. It has a bifunctional electronic structure of a triplet cabene joined to a singlet germylene (Structure 1).
Two New 3D Networks Co(II) Complexes Constructed via the Bridging Dicyanamide and 2,2′‐Bipyrimidine Ligands: Structures and Magnetic Properties
Authors: Chen Chiu‐Wang , Wei Ho‐Hsiang , Lee Chin‐Jhan 
Published: May 2015

AbstractTwo new complexes [Co(bipym)(dca)](dca) (1) and [Co(bipym)(dca)]2(ClO4)2 (CH3OH)·2H2O (2) (dca = dicyanamide, bipym = 2,2′‐bipyrimidine) have been synthesized and their structuresl magnetically characterized. Complex 1 crystallizes in amonoclinic system P21/n space group, Z = 4, with a = 9.3710(2), b = 15.0690(3), c = 9.8920(2) Å, β = 92.4780(10)°. Complex 2 crystallizes in a monoclinic system C2/c space group, Z = 4, with a = 16.4190(3), b = 17.0880(3), c = 12.1130(2) Å, and β = 95.1070 (10)°. The crystal structure in 1 and 2 is a three‐dimensional network contraction through the bridging 1,5‐dca and bipym ligands. Temperature dependence of magnetic measurements show antiferromagnetic couplings in all cases with J = −7.22 for 1, and −7.11 cm−1 for 2, respectively.
Controlling Length and Monitoring Growth of Gold Nanorods
Authors: Chen Hao‐Ming , Liu Ru‐Shi 
Published: May 2015

AbstractIn this paper, we report a new approach, which could fabricate gold nanowires by controlling the volume of growth solution. The shape evolutions ranging from fusiform nanoparticles to 1‐D rods was observed. Increasing the addition of growth solution can control the length of nanorods. The length of rods can be extended to 2 μm, and nanorods with aspect ratios of up to ˜ 70 could be obtained. Moreover, X‐ray absorption spectroscopy (XAS) is applied herein to elucidate the growth mechanism of gold nanorods. The gold ions were directly reduced to gold atoms by ascorbic acid during the reaction, and then gold atoms were deposited on the surface of gold seeds that were introduced into the reaction. Extended X‐ray absorption fine structure (EXAFS) confirmed the growth of gold and the environment around Au atoms over the reaction. The XAS are expected to have wide applications in the growth of gold and other related materials.
Multi‐Channel Piezoelectric Crystal Gas Sensor with Principal Component Analysis for Organic Solvent Pollutants from Polymer Plants
Authors: Wang Ya‐Ling , Shih Jeng‐Shong 
Published: May 2015

AbstractA multi‐channel piezoelectric (PZ) quartz crystal gas sensor coated with various organic adsorbents and a home‐made microcomputer interface for data processing have been fabricated for the detection of various organic vapors such as methanol, formic acid, propionaldehyde, carbon disulfide and N,N‐dimethyl formamide which are generally used as solvents in the polymer industry. The home‐made computer interface includes a digital Altera and an Intel‐8255 data processing system. The Principal Component Analysis (PCA) method was employed to analyze the frequency response signals from each channel with different coating materials and was applied to select the appropriate coating materials for these organic vapors. A dataset for the multi‐channel sensor with 29 PZ quartz crystals for these organic vapors was collected. Six representative coating materials such as C60‐polyphenyl acetylene (C60‐PPA), polyethylene glycol, Nafion, triphenyl phosphine, cryptand‐22 and polyvinyl pyrrolidone were selected after comparing the correlation between the 29 coating materials and the first four principal component (PC) factors of the PCA analysis. The 5 organic vapors can be effectively distinguished clearly by the six‐channel piezoelectric crystal sensor and which can be obviously found from the PCA Scores Map. Furthermore, different organic vapors tend to have distinguishing profile discrimination maps with the six channel PZ crystal sensor. The profile discrimination maps can be applied as fingerprints for these organic molecules. The six‐channel PZ crystal sensor has quite good detection limits for these organic vapors. Furthermore, the multivariate linear regression (MLR) analysis was also employed to compute the concentrations of methanol and carbon disulfide in the mixture of organic vapors.
Intramolecular Heck Reaction of Aryl Halide Tethered with Dienes as Acceptors: Studies of their 6‐endo‐trig versus 6‐exo‐trig Selectivities
Authors: Hon Yung‐Son , Hsu Yu‐Chia , Cheng Chia‐Yi 
Published: May 2015

AbstractThe palladium‐catalyzed intramolecular coupling reactions of aryl bromides tethered with conjugated dienoates give a 1 H‐isochromene ring system via 6‐endo‐trig cyclization almost exclusively. However, both 6‐endo‐trig and 6‐exo‐trig cyclizations are competitive processes in the palladium‐catalyzed intramolecular coupling reactions of aryl bromides tethered with conjugated dienones.
En Route to Improved Antimalarial Peroxides Following the Natural Role Model Artemisinin
Authors: Griesbeck Axel G. , El‐Idreesy Tamer T. 
Published: May 2015

AbstractThe synthesis of a series of 5‐cyclopropyl substituted 1,2,4‐trioxanes 3a‐3f by a sequence of singlet oxygen ene reaction with the 1‐cyclopropylated allylic alcohol 1 and subsequent peroxyacetalization reaction with aldehydes and ketones, respectively, is described. An important side reaction is the formation of cross‐peroxyacetalization products 4 and 5 from the Lewis‐acid catalyzed cleavage of the initially formed β‐hydroperoxy alcohol 2. The in vitro antimalarial activities of several derivatives 3 against Plasmodium falciparum are remarkably high.
Synthesis and Properties of Triptycene‐Diaminostilbene Hybrid Systems
Authors: Yang Jye‐Shane , Yan Jyu‐Lun 
Published: May 2015

AbstractThe synthesis, electronic spectra, and thermal and electrochemical properties of two triptycene‐capped trans‐4,4′‐diaminostilbenes (1Me and 1Ph) are reported in order to evaluate their applicability as blue light‐emitting materials in organic light‐emitting diodes (OLEDs). For comparison, the fluorescence properties of the planar analogs 2Me and 2Ph are also investigated. High fluorescence quantum yields (0.72–0.78) are observed for 1Me and 1Ph in THF, presumably due to a large barrier for the nonradiative double‐bond torsion reaction in the singlet excited state. In the spin‐cast thin films, the fluorescence quantum efficiencies become lower (0.15–0.26) and the fluorescence spectra are red‐shifted. Compared to 1Me and 1Ph, 2Me and 2Ph display even larger fluorescence shifts and fluorescence quenching, which can be attributed to their more planar structures that favor intermolecular π‐stacking in the solid state. The glass transition temperatures for 1Me and 1Ph are 113 and 120 °C, respectively, and the decomposition temperatures 341 and 375 °C, respectively. Cyclic voltammograms of 1Me and 1Ph show two reversible redox waves, corresponding to two monoelectronic oxidation processes of the amino groups forming radical cation and dication species.
(2,2′‐Bipyridine)palladiumdichloride Derivatives as Recyclable Catalysts in Heck Reactions
Authors: Lu Norman , Chen Jeng‐Yung , Fan Chi‐Wen , Lin Yan‐Chou , Wen Yuh‐Sheng , Liu Ling‐Kang 
Published: May 2015

AbstractFluorous ponytailed [PdCl2(4,4′‐bis(RfCH2OCH2)‐2,2′‐bpy)], (Rf = CF3(CF2)2 2a, HCF2(CF2)3 2b, HCF2(CF2)7 2c, and non‐fluorous [PdCl2(4,4′‐bis(CH3)‐2,2′‐bpy)] 3 were prepared and successfully employed in the catalyst reusage studies running the homogeneous Heck reaction of C6H5I and H2C=CHCO2CH3, the catalysts being recycled for 8 consecutive runs without loss of activity and the recovery procedure being the direct vacuum distillation of mixtures to take advantage of the very high thermal stability of these PdCl2(2,2′‐bpy) derivatives.
Catalytic Reaction of Para‐Isopropylbenzaldehyde with Propionaldehyde over Solid Base Catalysts
Authors: Shiau Shin Yi , Ko An‐Nan 
Published: May 2015

Abstract3‐(4‐Isopropyl‐phenyl)‐2‐methyl‐acrylaldehyde (4IP2MA) was synthesized from propionaldehyde (PA) and para‐isopropylbenzaldehyde (IPB) via cross aldol condensation over alkaline earth metal oxides or Al2O3‐MgO mixed oxides (AM) at 120–190 °C by using a batch reactor. The catalytic activity is enhanced with the base amounts of both alkaline earth metal oxides and the mixed oxides. The reaction system is free of diffusional limitation at a stirring speed larger than 600 rpm. Increasing the catalyst weight, reaction temperature, reaction time and IPB/PA mol ratio enhances the PA conversion, whereas the 4IP2MA selectivity remains small change except for IPB/PA ratio. Favorable results occur on the PA conversion and the 4IP2MA selectivity for the reaction in nonpolar solvents of cyclohexane and benzene. Reused catalysts of MgO and AM exhibit no catalyst decay. For the formation of 4IP2MA, the reaction mechanism is proposed and the apparent activation energy is calculated.
Synthesis and Biological Evaluation of 5′‐Triazole Nucleosides
Authors: Lee Lenselot , Chang Kai‐Hsuan , Valiyev Famil , Liu Hsing‐Jang , Li Wen‐Shan 
Published: May 2015

AbstractThe first series of 5′‐triazole cytidines 1a‐d and adenosines 2a‐c was prepared and evaluated for inhibitory potency toward α‐2,3‐sialyltransferase. The synthesis of target compounds was achieved by converting the 5′‐alcohol of protected nucleosides to the azide derivatives, which were then coupled with the alkynes by copper(I)‐catalyzed cycloaddition to give protected 5′‐triazole nucleosides 3a‐d/7a‐c, followed by deprotection. 5′‐Triazole adenosines 2a‐c were less efficient inhibitors of α‐2,3‐sialyltransferase than their cytidine analogues 1a‐d. 1d was the most active compound with an IC50 of 37.5 μM. These results suggested that the hydrophobic functionality and the cytidine group are clearly required for the improved binding.