bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Convenient Solid State Method for Preparing Aryl Azo Compounds
Authors: Wang Cai‐Lan , Wang Yu‐Lu , Wang Xiao‐Yang , Wang Xiao‐Xia , Li Jian‐Ping 
Published: May 2015

AbstractA convenient solid state reaction using ferric nitrate to oxidize substituted semicarbazide for preparing azo ureas has been reported for the first time. Eight phenyldiazenecarboxylic acid anilide derivatives, have been synthesized in excellent yields with cheap reagents and simple instruments under room temperature.
The Constituents of Cananga odorata
Authors: Hsieh Tian‐Jye , Chang Fang‐Rong , Wu Yang‐Chang 
Published: May 2015

AbstractSixteen compounds, (+)‐ushinsunine‐β‐N‐oxide (1), cleistopholine (2), liriodenine (3), (‐)‐anonaine (4), (+)‐nornuciferine (5), (+)‐N‐acetylnornuciferine (6), (‐)‐ushinsunine (7), (‐)‐norushinsunine (8), (‐)‐asimilobine (9), (+)‐reticuline (10), N‐trans‐feruloyltyramine (11), β‐sitosterol (12) and stigmasterol (13), lyscamine (14), (‐)‐anaxagoreine (15) and trans‐cinnamic acid (16) were isolated from the methanolic extract of the Cananga odorata. Among them, 1 is a new stereoisomer of ushinsunine‐β‐N‐oxide. The structures of these compounds were established by means of spectral experiments.
Tannin and Related Compounds from Terminalia catappa and Terminalia parviflora
Authors: Lin Ta‐Chen , Hsu Feng‐Lin 
Published: May 2015

AbstractContinuing chemical examination on tannins and related compounds of Combretaceous plants has led to the isolation of one novel complex type tannin, catappanin A, together with two phenolcarboxylic acids, two phenol glucoside gallates, seven ellagic tannins, one other hydrolyzable tannin, four flavan‐3‐ols and two complex type tannins from the bark of Terminalia catappa. In addition, from the bark of Terminalia parviflora one new methyl glucoside gallate, methyl 3,6‐di‐O‐galloyl‐β‐D‐glucoside, three phenolcarboxylic acids, three gallotannins, six ellagitannins and three other hydrolyzable tannins were isolated. Their structures were elucidated on the basis of chemical and spectroscopic evidence.
The Formation of Triple Stranded Helix of Oligodeoxyribonucleotides Containing 8‐Oxo‐2′‐deoxyadenosine
Authors: Lin Shwu‐Bin , Wu Chia‐Mau , Lin Wei‐Chen , Kan Lou‐Sing 
Published: May 2015

AbstractTriple stranded DNA helix (triplex) formation is limited by pH and the sequence of oligodeoxyribonucleotide. In this study, the 8‐oxo‐2′‐deoxyadenosine (8‐oxoA) can replace 2′‐deoxycytidine for forming a base triad with a base pair guanine and cytosine. The target for the triplex formation is a motif of a promotor (5′‐d‐TTGGGGGGGAA, −3 – −12 of PKCα m‐RNA) of mouse protein kinase Cα. The probes contain 20 bases with a common sequence 5′‐d‐XXXXXXTTCCCCCCAA. The XXXXXX portion may contain either 5‐methyl‐2′‐deoxycytidines, six 8‐oxoA's or both. Only the probe with a motif of six 8‐oxoA's can for triplex with the target in the presence of magnesium ion and spermine at neutral pH. Therefore, 8‐oxoA is useful for triplex formation under physiological conditions.
Bacterially Expressed Raf‐1 Catalytic Domain is Highly Associated with GroEL
Authors: Ho Mengfei , Wilson Brenda A. , Peterson John W. 
Published: May 2015

AbstractRaf‐1 is a key protein kinase in the mitogen‐activated protein kinase cascade. We have subcloned the catalytic domain of Raf‐1 into the bacterial expression vectors, pTrcHisB and pGEX‐6P‐1, denoted as His6‐ΔNRaf and GST‐RafBXB, respectively. Chromatography of the recombinant proteins using Ni‐NTA agarose, Sephacryl S‐300, and glutathione‐sepharose revealed association of Raf‐1 catalytic domain in a high molecular weight complex with a 57 kDa protein. Microsequencing of this 57 kDa protein identified it as GroEL, a heat shock protein in E. coli important for protein folding. GroEL association with the Raf‐1 catalytic domain is specific, as evidenced by its association with both Raf‐1 constructs. Native‐PAGE gels and Western analysis of gel filtration fractions revealed association of the catalytic domain with a large molecular weight complex consistent with the tetradecameric complex of GroEL. A peptide library of 384 do‐decapeptides corresponding to the entire catalytic domain of Raf‐1 was constructed by the spot synthesis method. Binding of GroEL and ELISA analysis revealed a preferential GroEL binding site in the β1 sheet region of the Raf‐1 kinase domain.
Beckmann Rearrangement of Cyclohexanone Oxime over Borate‐Pillared LDHs
Authors: Lin Jenn‐Tsuen , Tsai Shi‐Jane , Cheng Soofin 
Published: May 2015

AbstractBorate‐pillared layered double hydroxides (LDHs) were studied as catalysts in vapor‐phase Beckmann rearrangement of cyclohexanone oxime to caprolactam under atmospheric pressure. The results were compared with those over the physical admixture of LDH and boria, the co‐precipitate of B‐Mg‐Al hydroxide, and the pristine LDH and boria compounds. Although oxime conversion and caprolactam selectivity declined with time‐on‐stream over all the catalysts, borate‐pillared LDH catalysts could retain activity longer than pure boria or those prepared by other methods. The decay rate however was affected by the Mg/Al ratio, the boron content and the form of LDH precursor used. The LDH itself functioning as a basic catalyst contributed to the formation of side products such as cyclohexanone and 2‐cyclohexen‐1‐one. The physical admixtures of LDH and boria had catalytic properties more close to that of pure boria, which gave high caprolactam selectivities but lost the activity in several hours on stream. The high resistance to decay of the pillared catalysts was attributed to that boria in the interlayer of LDH was stabilized and prevented from structural transformation to a glassy state of no activity.
Lignans, Flavonoids and Phenolic Derivatives from Taxus mairei
Authors: Yang Shung‐Jim , Fang Jim‐Min , Cheng Yu‐Shia 
Published: May 2015

AbstractFrom the twigs of Taxus mairei, 35 lignans, 2 sesquilignans, 4 flavonoids, 3 bisflavonoids, 13 phenolic derivatives, 2 sesquiterpenes, 3 bisnorsesquiterpenes, 3 long‐chain carboxylic acids and 4 steroids were isolated. The new lignans and phenolic glucosides include 7′‐hydroxynortrachelogenin, 7‐hydroxymatairesinol, 3′‐O‐demethylepipinoresinol, taxiresinol 9‐acetate, 3′‐O‐demethyltanegool, 8′‐epitanegool, 3,3′‐dimethoxy‐4,4′,9‐trihydroxy‐7,9′‐epoxylignan‐7′‐one, 3‐O‐demethyldihydrodehydrodiconiferyl alcohol, taxumaiglucoside A heptaacetate, taxumaiglucoside B heptaacetate, and taxumaiglucoside C heptaacetate. Their structures were determined by spectral methods.
Pregnane Glycosides from Gymnema alternifolium
Authors: Lin Yun‐Lian , Wu Yan‐Ming , Kuo Yueh‐Hsiung , Chen Chieh‐Fu 
Published: May 2015

AbstractThree new polyoxypregnane glycosides, gymnepregosides G, H, and I, together with four known compounds were isolated from the stems of Gymnema alternifolium. The structural elucidation were determined principally by spectral data, and assigned to be 12‐O‐cinnamoyl‐3β,5α,8β,12β,14β,17β,20‐heptahydroxy‐(20S)‐pregn‐6‐enyl‐3‐O‐β‐D‐cymaropyranoside (1), 20‐O‐benzoyl‐12‐O‐cinnamoyl‐3β,5α,8β,12β,14β,17β,20‐heptahydroxy‐(20S)‐pregn‐6‐enyl‐3‐O‐β‐D‐cymaropyranoside (2), and penupogenin 3‐O‐β‐D‐cymaropyranoside (3), respectively.
Determination of Mercury in Urine and Seawater by Flow Injection Vapor Generation Isotope Dilution Inductively Coupled Plasma Mass Spectrometry
Authors: Wei Ming‐Tsai , Jiang Shiuh‐Jen 
Published: May 2015

AbstractA simple and inexpensive laboratory‐built vapor generator was used with inductively coupled plasma mass spectrometry (ICP‐MS) for the determination of mercury in urine and seawater samples. The applications of vapor generation ICP‐MS alleviated the non‐spectroscopic interferences and the sensitivity problem of mercury determination encountered when the conventional pneumatic nebulizer was used for sample introduction. The concentration of mercury was determined by isotope dilution method. The isotope ratio of mercury was calculated from the peak areas of each injection peak. The repeatability of the peak areas and isotope ratio determinations of seven consecutive injections of 1 ng mL−1 Hg solution were 2.3% and 2.2%, respectively. This method has a detection limit of 0.07 ng mL−1 for mercury. This method was applied to determine mercury in a CASS‐3 nearshore seawater reference sample, NASS‐4 open ocean seawater reference sample, NIST SRM 2670 freeze‐dried urine reference sample and several urine and seawater samples collected from National Sun Yat‐Sen University. The results for the reference samples agreed satisfactorily with the reference values. Results for other samples analyzed by the isotope dilution method and the method of standard additions agreed satisfactorily. Precision was better than 10% for most of the determinations.
Kinetic Study of the Ru(II) Catalyzed Oxidation of Pentacyanoferrate(ll) Complexes by Peroxydisulfate
Authors: Wei Shi‐Kai , Yeh Andrew 
Published: May 2015

AbstractThe oxidation reactions of Fe(CN)5L3− (L = 4‐ampy, py, dpa) complexes by S2O82− were catalyzed upon the addition of a trace amount of Ru(NH3)5L′2+ (L′ = pz, py or dcb) complex, and the reaction becomes zero‐order in Fe(II). The reaction time is ∼102 fold faster than the simple Fe(CN)5L3−‐S2O82− system. The mechanism of this Ru(II) catalyzed redox reaction is proposed asRu(NH3)5L′2+ + 1/2 S2O82− → Ru(NH3)5L′3+ + SO42−Ru(NH3)5L′3+ + Fe(CN)5L3− ⇌ Ru(NH3)5L′2+ + Fe(CN)5L2−
Structure, Magnetic Properties and Catalase‐like Activity of Asymmetric Dimanganese(III, III) Carboxylate Complexes with Salicylaldimine Ligands
Authors: Chang Kuo‐Hui , Wei Ho‐Hsiang , Hong Dang‐Ming 
Published: May 2015

AbstractThe crystal structures, magnetic properties, and catalase‐like activities of assymmetric dinuclear manganese(III, III) complexes, [Mn2III, III(spa)2(μ‐Me3CCO2)(Me3CCO2)(CH3OH)] (1) and [Mn2III, III(vpa)2(μ‐Me3CCO2)(Me3CCO2)(CH3OH)] (2), (H2spa = 3‐salicyclideneamino‐1‐propanol, H2vpa = O‐vanillin), were reported. The crystal structures of complexes 1 and 2 consist of the same discrete asymmetric coordination environment of dinuclear clusters, where the two manganese atoms are bridged by two alkoxo oxygens of the spa or vpa ligands and one bidentate carboxylate ion, whereas an additional oxygen atom of monodentate carboxylate coordinated to the first metal ion, and the second metal ion was coordinated by one oxygen atom of the solvent CH3OH. Magnetic investigations (2–300 K) reveal an intramolecular antiferromagnetic spin exchange interaction with axial‐field splittings: J = −12.3 cm−1 (D = −0.10 cm−1) and J = −13.3 cm−1 (D = −0.15 cm−1) for complexes 1 and 2, respectively. The complexes should show catalase‐like activity for H2O2 disproportionation in CH3OH solvent at 25° with rate constants of k = 6.35 dm3moI−1s−1 and 6.20 dm3mol−1s−1 for complexes 1 and 2, respectively.
Thermodynamics of Binding 2,2′‐Bipyridineglycinato Palladium (II) Chloride on Human Serum Albumin
Authors: Saboury A. A. , Shamsaei A. A. , Moosavi‐Movahedi A. A. , Mansuri‐Torshizi H. 
Published: May 2015

AbstractThe interaction of human serum albumin (HSA) with 2,2′‐bipyridineglycinato palladium (II) chloride was studied by isothermal titration microcalorimetry at 27°C and equilibrium dialysis and UV‐Vis. spectrophotometry techniques at temperatures of 27 & 37°C in 2.5 mM phosphate buffer solution at pH = 7.0. The enthalpy of binding was calculated from binding data, which were obtained from equilibrium dialysis in terms of the Wyman binding potential theory related to the van't Hoff relation. The enthalpy of HSA unfolding was determined by subtraction of the microcalorimetric enthalpy (binding and unfolding enthalpies) and the enthalpy of binding. The enthalpy of HSA unfolding, due to the binding of that ligand, was 491.43 kJ mol−1.
Total Synthesis of (±)‐Iridolactone
Authors: Lee An‐Yang , Chang Meng‐Yang , Tai Huo‐Mu , Chang Nein‐Chen 
Published: May 2015

AbstractA total synthesis of (±)‐iridolactone (1) from bicyclo[2.2.1]ketone 6 is described. Trisubstituted cyclopentenoid aldehyde 7 is a key intermediate.
Ene Reaction with Pummerer‐Type Reaction Intermediate of α‐(Methylthio)isobutyl Acetamide: A New Synthesis of Pellitorine
Authors: Chen Ling‐Ching , Kang Iou‐Jiun , Wang Huey‐Min 
Published: May 2015

AbstractPummerer‐type reaction intermediate 2 of α‐(methylthio)isobutyl acetamide (1) has been found to react with 1‐alkenes to afford ene adducts 3. Pellitorine 4 was synthesized from the adduct 3d.
Investigation of the Reaction of Roasted Serpentine Ore with Some Ammonium Salts
Authors: Abd‐Elzaher Mokhles M. 
Published: May 2015

AbstractThe reaction between roasted serpentine ore and ammonium sulfate was studied at the range of temperature 250–1000°C using different molar ratios to determine the maximum extraction of magnesia and also to characterize the different reaction products. The maximum extraction of MgO from the roasted ore reached 92.4% at 400°C. It was found from XRD that ammonium magnesium sulfate [(NH4)2Mg2(SO4)3] was produced as the main product at 400°C, which decomposes to magnesium sulfate at 500–600°C. The last compound decomposes to magnesium oxide at 900–1000°C. Thermal analysis of the reaction mixture confirmed the results obtained by XRD. Extraction of magnesia by ammonium chloride at 300–400°C showed low percentage of extraction (7.8%). Comparison was made between using ammonium chloride instead of sulfate taking into consideration the thermal decomposition products of both ammonium salts. Extraction of magnesia from the roasted ore by aqueous ammonium sulfate or ammonium chloride showed good results.
Influence of Short‐Chain Alcohols on the Micellization Parameters of Sodium Dodecyl Sulfate (SDS)
Authors: Safarpour M. A. , Rafati A. A. , Gharibi H. , Sameti M, Rezaie 
Published: May 2015

AbstractThe influence of short‐chain alcohol on the aggregation behavior of Sodium Dodecyl Sulfate (SDS) is investigated within a wide range of alcohol concentration by potentiometric technique. It is observed that aggregation behavior of SDS is a function of alcohol concentration. Variation of micellization parameters are studied in a wide range of alcohol concentration and the trend of changing of micellization parameters have been investigated. The variations of micellization parameters show several regularities. Finally, the relationships between these regularities and alcohol‐surfactant interactions have been explained.
Synthetic Applications of 3‐(Phenylsulfinyl)‐3‐sulfolene
Authors: Chou Shang‐Shing P. , Liang Pi‐Wei 
Published: May 2015

AbstractThe title compound 2 was readily prepared by MCPBA oxidation of the sulfide 1. Thermal desulfonylation of 2 gave the sulfoxide‐substituted diene 3. The Diels‐Alder reactions of 3 with various dienophiles gave the cyclized products 4‐9 in good yields. The regiochemistry was found to be dominated by the phenylsulfinyl group, but could be reversed by the presence of a Lewis acid. Deprotonation of 2 by BuLi, followed by the reaction with alkyl halides, gave the substituted 2‐sulfolenes 10. A synthetic application of 10 was demonstrated by converting 10e to the bicyclic product 11.
Syntheses of L‐Glutamic Acid Analogues for Neuroexcitatory Activity Studies
Authors: Hon Yung‐Son , Chang Yen‐Chung , Chu Kuan‐Po 
Published: May 2015

AbstractStarting from D–serine, (2S,3S)‐, (2S,3R)‐substituted‐L‐glutamic acids were prepared via Claisen rearrangement methodology. A variety of the substituents can be introduced at the C‐3 of the L‐glutamic acid backbone.
Ultrafast Dynamics Probed by the Time‐Resolved Anisotropy Measurements
Authors: Hayashi M. , Yang T. S. , Liang K.‐K. , Chang C.‐H. , Chang R.‐L. , Lin S. H. 
Published: May 2015

AbstractIn this paper, we shall show that in order to effectively observe the quantum beat due to vibrational coherence by the anisotropy measurement, it is necessary to perform the frequency‐resolved measurement in the transient absorption. It is found that the quantum beat due to vibrational coherence cannot be observed if the ultrafast processes under observation do not involve an electronic transition.In order to effectively observe the quantum beat due to vibronic coherence, it is necessary to perform the frequency‐integrated time‐resolved anisotropy measurement. We also show that it is usually difficult to obtain accurate dynamics information from the time‐resolved anisotropy measurement.
Theoretical Study of the Germylene Insertion Reaction into the A‐H Bond of First‐Row and Second‐Row AHn Hydrides
Authors: Su Ming‐Der , Chu San‐Yan 
Published: May 2015

AbstractThe insertion of dimethylgermylene into the A–H bond of AHn hydrides is calculated using the CCSD(T) method in comparsion with the density functional theory (B3LYP) with the 6‐311G* basis set. The B3LYP values reproduce the CCSD(T) results very well. The present theoretical calculations suggest that (a) for germylene insertions there is a very clear trend toward lower activation barriers and more exothermic interactions on going from left to right along a given row, and (b) for the second‐row hydrides, the insertion reactions are more exothermic than for the first‐row hydrides, and the reaction barriers are lower.
The Bonding Structure of Quadricyclanylidene Derivatives
Authors: Chow Tahsin J. , Lee Chia‐Fu , Lin Kuan‐Jiuh 
Published: May 2015

AbstractThe crystal structures of bisquadricyclanylidene 1, 7‐quadricyclanylidenenorbornadienes 2 and 3 are solved by X‐ray diffraction analyses. The bond lengths of the cyclopropyl moieties of 1, 2 and 3 are compared with several other quadricyclanylidene derivatives, and the differences are analyzed by computational models. The results showed that the variation of bond lengths in this series of compounds is related to the electronic nature of substituents.
Aluminium Chloride‐Catalyzed Intermolecular vs Intramolecular Friedel‐Crafts Reaction of Acrylanilides and 3‐Chloropropanamides
Authors: Chen I‐Li , Wang Tai‐Chi , Chen Yeh‐Long , Tzeng Cherng‐Chyi 
Published: May 2015

Abstract3‐Phenylpropionanilide (4a) is obtained in a yield of 89% from acrylanilide by the treatment with AlCl3/benzene, compared with a yield of 39% by the 1,4‐conjugate addition of phenyllithium. The formation of 4a indicated that an intermolecular Friedel‐Crafts reaction occurred, rather than the relatively more facile intramolecular ring cyclization, and provided a more efficient route than a conjugate addition of phenyllithium for the preparation of 3‐phenylpropionanilide and its derivatives. Although the methoxy group is an activator of the nucleophilic substitution, introduction of a methoxy substituent at N‐phenyl did not increase the competitive capability of the intramolecular cyclization because of AlCl3‐catalyzed demethylation to form the ArOAlCl2 complex which decreased the availability of the π‐electron in the N‐phenyl aromatic system.
Chromatographic Chiral Recognition and Computer Aided Deconvolution of the Enantiomeric Secondary Alcohol with a Self‐Packed Chiral Stationary Phase HPLC Column
Authors: Cheng Cheanyeh , Wu Shouh‐Chwan 
Published: May 2015

AbstractThe γ‐aminopropyl‐derivatized silica was treated with the (R)‐(‐)‐N‐(3,5‐dinitrobenzoyl)‐α‐phenylglycine and was packed into a standard 250 mm × 4.5 mm HPLC column to perform the chiral separation of secondary alcohol. Enantiomers of four homologous series of aryl alkyl substituted alcohol were resolved in different degrees. The chiral recognition mechanism was proposed that could be used to rationalize well the elution order and the resolution between the R‐ and S‐configuration of a secondary alcohol. The unresolved peak of the enantiomers of 1‐phenylethanol and the partially resolved peak of the enantiomers of 1‐(1‐naphthyl)ethanol were deconvoluted by the assistance of computer and a program written in BASIC computer language. Two mathematical models were used for the deconvolution and were based on modified Gaussian functions with a fixed baseline that can take into account the skew of a chromatographic peak. Parameters in the mathematical model were estimated by using a nonlinear regression algorithm. The selected mathematical models were suitable for deconvolving the less skewed overlapping peaks of 1‐phenylethanol.
Syntheses of 4‐(5‐oxo‐1,2,4‐triazol‐3‐yl)‐sydnones and 4‐(4‐arylamino‐5‐oxo‐1,2,4‐triazol‐3‐yl)‐sydnones from Sydnone Derivatives and Their Fragments
Authors: Kuo W. F. , Lee C. Y. , Yeh M. Y. 
Published: May 2015

Abstract4‐(5‐oxo‐1,2,4‐triazol‐3‐yl)‐sydnones 11 and 4‐(4‐arylamino‐5‐oxo‐1,2,4‐triazol‐3‐yl)‐sydnones 13 have been obtained from a‐chloroformylarylhydrazine hydrochloride 2. Moreover, the intermediates, including 3, 4, 9 and 10, in this study are synthetically informative and valuable. It is also noteworthy that three reactants, 1, 2 and sydnonecarbaldehydes, were prepared from sydnone derivatives and their fragments. The oxidative cyclizations of sydnonecarbaldehyde semicarbazones 9 and carbazones 10 with two different oxidizing agents (Cu(ClO4)2 and Fe(ClO4)3) have been extensively examined. The reaction time and the yields of cyclizations were affected by the substituents of semicarbazones 9 and carbazones 10.
Constituents of the Whole Herb of Clinoponium laxiflorum
Authors: Kuo Yueh‐Hsiung , Lee Shu‐Mei , Lai Jeng‐Shiow 
Published: May 2015

AbstractThe isolation and identification of twenty‐two components (including one new compound) from the whole herb of Clinoponium laxiflorum (Hay) Matsum (Labiatae) are described. Their structures were determined on the basis of spectral and chemical transformation. One new compound is methyl rosmarinate. The other twenty‐one compounds include three steroids (α‐spinasterol, α‐spinasteryl‐3‐O‐β‐D‐glucopyranoside, and β‐sitosteryl‐3‐O‐β‐glucopyranoside), three triterpenes (oleanolic acid, ursolic acid, and betulinic acid), nine flavonoids (didymin, apigenin‐7‐O‐β‐glucopyranoside, luteolin‐7‐O‐β‐glucopyranoside, isosakuranetin, narigenin, apigenin, luteolin, narirutin, and hesperidin), three lignolic acids (rosmarinic acid, 3‐(3,4‐dihydroxyphenyl)lactic acid, and caffeic acid), and three phenols (4‐hydroxybenzaldehyde, 3,4‐dihydroxybenzaldehyde, and 3,4‐dihydroxybenzoic acid).
Synthesis of Optically Active Tetraoxa‐Cage Compounds by Chemical Resolution
Authors: Chen I‐Chia , Wu Hsien‐Jen 
Published: May 2015

AbstractThe first synthesis of optically active tetraoxa‐cage compounds has been accomplished by using (‐)‐camphanic chloride as a resolving reagent in a short sequence. The synthesis of the tetraoxa‐cages with different functional groups on the side chain was also demonstrated.
Carbon‐13 Nuclear Magnetic Resonance Spectroscopic Analyses of 3‐Aryl‐3‐hydroxyl‐2,2,4,4‐tetramethylcyclobutanones and Related Compounds
Authors: Lin Shaw‐Tao , Lin Wen‐Chung , Yeh Yuen‐Han 
Published: May 2015

AbstractA series of 2‐aryl‐2‐hydroxy‐1,1,3,3‐tetramethyl‐5,8‐dioxaspiro[3.4]octanes (1), 3‐aryl‐3‐hydyoxyl‐2,2,4,4‐tetyramethylcyclobutanones (2), and l‐aryl‐2,2,4‐trimethyl‐1,3‐pentadiones (3) were studied using 13C NMR analyses. The chemical shifts of C‐c are dependent on the substituent groups on the phenyl ring for compounds 1 (ρ =‐0.966, R2 = 0.987) and 2 (ρ = −1.378, R2 = 0.998). The chemical shifts of C‐a follow a similar trend (ρ =−0.926, R2 = 0.989). In the case of compounds 3, C‐c yielded the opposite trend with very poor correlation coefficiency (ρ = 1.22, R2 = 0.179). This result reveals the field effect of a polar bond and resonance‐induced changes in pi electron‐density at C‐1 on the cyclobutanering series.
Dimerization and Oligomerization of Ethylene Catalyzed by a Palladium(II) Complex with Imine‐phosphine Ligand
Authors: Chen Jwu‐Ting , Liu Shiuh‐Tzung , Zhao Ke‐Qing 
Published: May 2015

AbstractThe palladium‐iminophosphine complex [Pd(P‐N)(CH3)Cl] (P‐N = o‐diphenyl‐phosphino‐N‐benzaldimine) has been found to be a catalyst for dimerization and trimerization of ethylene. Some mechanistic insight concerning this oligomerization is discussed.
A Convergent Formal Synthesis of (±)‐Pumiliotoxin C
Authors: Shieh Ya‐Sheng , Yeh Ming‐Chang P. , Rao U. Narasimha 
Published: May 2015

AbstractA short approach to a key precursor in the synthesis of (±)‐pumiliotoxin C was achieved from [(6–9‐ẽ)‐ethyl cis‐6,8‐nonadienoate]tricarbonyliron complex in five steps.