bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chiral Synthons by Ester Hydrolysis Catalyzed by Pig Liver Esterase
Authors: Ohno Masaji , Otsuka Masami 
Published: February 2005

AbstractDevelopment of efficient methodology to produce an optically pure enantiomer is of fundamental importance, particularly for the synthesis of biologically active natural products. Optically active compounds can be obtained by three different approaches, that is, resolution of racemates, use of a chiral pool or “chiron” (which are enantiomerically pure synthons), or asymmetric synthesis. Of these, one of the more challenging tasks involves asymmetric synthesis, which may be carried out either enzymatically or nonenzymatically. Whereas the nonenzymatic method enables us to introduce a chiral center with either a stoichiometric or catalytic amount of a chiral compound, the enzymatic method uses biological systems, such as microorganisms or isolated enzymes, to create the center of asymmetry. The purpose of this chapter is to survey asymmetric synthesis via the production of enantiomerically pure or enriched organic molecules by the enzymatic method focusing on the use of a hydrolytic enzyme, pig liver esterase (PLE; Enzyme Commission classification number, E.C. 3.1.1.1).Enzymes are classified into the following six groups based on the reactions they catalyze:Oxidoreductase (oxidation–reduction reactions);Transferase (transfer of functional groups);Hydrolase (hydrolysis reactions);Lyase (addition to double bonds or the reverse);Isomerase (isomerization reaction); andLigase (formation of bonds coupled with pyrophosphate bond cleavage of ATP).Virtually all biochemical transformations are catalyzedin vivoby these six groups, and the biochemical aspects of these enzymes have been studied in detail. However, the practical utility of these enzymes in organic synthesis remains to be further exploited and refined. The ability of a substrate to associate with an enzyme is also one of the most significant problems. In some cases, these problems have been overcome and several enzyme reactions have been successfully used on a large scale.An enzyme reaction generally takes place when an intimate interaction between the reactant and the chiral catalyst (enzyme protein) is realized. This enzyme–substrate complex is designated as the Michaelis complex. Certain amino acid residues of the enzyme form a three‐dimensional structure as the active site. This site often contains reactive groups of the amino acids such as amino, mercapto, hydroxyl, carbonyl, carboxyl, guanidino, or imidazolyl. When the substrate is bound to the active site in a specific orientation, enantiotopic groups or faces of the substrate molecule are discriminated by the chiral enzyme. This discrimination is sufficiently sensitive to differentiate between the two hydrogen atoms in a methylene group. Thus the reaction proceeds stereospecifically. The enzyme can also distinguish among several substrates competing for an active site. Such substrate specificity is sometimes strict and sometimes broad. Synthetically useful enzymes should accept a wide range of substrates and exhibit high stereospecificity. Many enzymes meet these criteria, and PLE is one of them.
ThePeterson Olefination Reaction
Authors: Ager David J. 
Published: February 2005

AbstractThe Peterson olefination reaction provides a useful method for the preparation of alkenes from α‐silyl carbanions and carbonyl compounds. As alkenes hold a pivotal role in synthetic methodology for the introduction of vicinal functionality, particularly in a stereoselective manner, the Peterson reaction is increasing in importance in the reaction repertoire. This chapter discusses the reaction and its advantages over comparable methods such as the Wittig reaction.Although elimination of β‐silylalkoxides, was noted in 1947, it was not until Peterson described the preparation of functionalized alkenes from α‐silyl carbanions in 1968 that the full potential of the reaction became apparent. Alkenes are usually only isolated directly from the condensation when an anion‐stabilizing group is present in the carbanion; if not, the β‐hydroxysilane is formed. Many examples of the formation of alkenes from β‐hydroxysilanes are cited in the literature. These eliminations are discussed in this chapter, although they strictly should not be called Peterson olefination reactions. However, the “common” organic reactions of β‐hydroxysilanes which follow the usual pathways—such as the thermolytic elimination of esters derived from those alcohols—are omitted.The central nature of the Peterson reaction to organosilicon chemistry has led all reviews in this area to discuss the subject to some extent. In addition, the reaction itself has been reviewed previously.
TheNef Reaction
Authors: Pinnick Harold W. 
Published: February 2005

AbstractThe Nef reaction is usually defined as the conversion of a primary or secondary nitroalkane into the corresponding carbonyl compound. This reaction was reported by the Swiss chemist J. U. Nef in 1894. Hydrochloric and sulfuric acid give the same result. The conversion of a nitro group to a carbonyl group has become an important synthetic tool because of the ease of preparation of substituted nitro compounds by condensation of nitroalkanes with aldehydes (the Henry reaction), conjugate addition of nitroalkanes to electrophilic alkenes, or carbon alkylation of the dianion of primary nitroparaffins. The Nef reaction is one of the better examples of “umpolung” reactivity in which the original nitro compound anion functions as an acyl anion equivalent.This chapter discusses the Nef reaction and modifications of the original process that extend the variety of compounds which are useful as substrates. Each modification is considered according to general mechanistic type and is organized in a “reagent” approach. The Tabular Survey lists all known examples of both the Nef reaction and these modifications so that specific comparison of methods can be made.
Twinning in Nanocrystalline fcc Metals
Authors: Frøseth A. G. , Derlet P. M. , Van Swygenhoven H. 
Published: February 2005

AbstractTwinning has been observed in experimental deformation studies of nanocrystalline (nc) materials even for high stacking fault fcc metals. By using molecular dynamics and a knowledge of the general planar fault energy curves of the corresponding metal, we show how twinning can occur by means of partial dislocations nucleating at nc grain boundaries and how this process is influenced by the presence of grown‐in twins.
Synthesis of Bulk Nanocrystalline Materials by Repeated Cold Rolling
Authors: Wilde G. , Dinda G.‐P. , Rösner H. 
Published: February 2005

AbstractThe article gives an overview on the preparation and characterization of bulk nanocrystalline or bulk amorphous metallic materials by repeated cold rolling with intermediate folding. The results that are highlighted for pure fcc and hcp metals and one binary glass‐forming alloy indicate that truly nanocrystalline materials with grain sizes below 10 nm can be obtained by this process that does not apply an additional hydrostatic pressure and that is compatible with continuous processing routes.
Studies on strongly swirling flows in the full space of a volute cyclone separator
Authors: Hu L. Y. , Zhou L. X. , Zhang J. , Shi M. X. 
Published: February 2005

AbstractThe three‐dimensional (3‐D) strongly swirling turbulent flows in the full space of a volute cyclone separator was measured using laser Doppler velocimetry (LDV), and was simulated using an improved Reynolds stress equation model by modifying the empirical constants in the isotropization of production and convection model (IPCM) + wall pressure–strain term of the Reynolds stress equation, incorporated into the platform of FLUENT 6.0. Predicted Reynolds stress model (RSM) velocities are more reasonable than those obtained previously. The specific features of turbulent flows in the separation space, dust hopper, annular space, and the outlet tube are different. The results show that the time‐averaged tangential velocity profiles in the separation space have a typical Rankine‐vortex structure. In some regions, such as the entrance, the vicinity of the top of the annular space, the inner vortex‐flow region, the vicinity of the discharge port, the vicinity of the wall, the intersection part between the upward and downward flows, the turbulent intensity is very large and changes sharply; the turbulence is anisotropic in most regions, but the magnitudes of three RSM velocity components are of the same order of magnitude. The distribution of time‐averaged tangential velocity is asymmetric in the annular space. The longitudinal secondary vortexes exist near the top of the dust hopper and the top of the cyclone. The distribution of time‐averaged axial velocity in the exit tube is entirely different from that in the separation space. © 2005 American Institute of Chemical Engineers AIChE J, 51: 740–749, 2005
Turbulent mixing in a tubular reactor: Assessment of an FDF/LES approach
Authors: van Vliet E. , Derksen J. J. , van den Akker H. E. A. 
Published: February 2005

AbstractThe aim of the present research was to investigate the feasibility of a probability density function (PDF) methodology combined with a large eddy simulation (LES) for turbulent reactive mixing in industrial geometries. In order to incorporate the PDF transport equation into a LES context, a filtered version was employed, denoted as filtered density function (FDF) equation. Using FDF/LES, the yield of mixing‐sensitive, parallel competitive reactants was numerically studied in a tubular reactor with perpendicular inlet operated at Re = 4,000 for varying Damköhler numbers and feed‐stream concentrations. The “interaction by exchange with the mean” (IEM) model was used to close the filtered conditional scalar energy dissipation rate (SED) appearing in the FDF equation. The modeling assumptions were assessed by means of laser induced fluorescence (LIF) experimental data, providing the mean conserved concentration field in a horizontal and vertical center plane downstream the injector, and concentration PDF's at several downstream positions. In the vicinity of the injector, the FDF/LES model slightly overpredicts both the spreading of jet and the dissipation of small scale fluctuations, which was attributed to the overprediction of the turbulent diffusivity in the transition region of the laminar jet to the the turbulent wake of the injector. Further downstream, however, the global macro transport of the reactants was qualitatively well predicted, and the sensitivity of the yield to the Damköhler number and feedstream concentration showed consistent behavior. © 2005 American Institute of Chemical Engineers AIChE J, 51: 725–739, 2005
Flow normal to a flat plate of a viscoplastic fluid with inertia effects
Authors: Savreux Frédéric , Jay Pascal , Magnin Albert 
Published: February 2005

AbstractThe two‐dimensional (2‐D) flow normal to a flat plate of a Bingham fluid is studied numerically. The effects of plasticity and inertia are investigated. The detailed structure of the flow is examined in relation to a large range of the Oldroyd number (0 ≤ Od ≤ 100) and of the Reynolds number (0 ≤ Re ≤ 10). The strong influence of these parameters, especially on the rigid zones and on the vortex zone, is shown. The drag coefficient is also calculated and some analytic relationships are proposed. The results are compared with the few other data available. © 2005 American Institute of Chemical Engineers AIChE J, 51:750–758, 2005
Polyazide Chemistry: Preparation and Characterization of As(N3)5, Sb(N3)5, and [P(C6H5)4][Sb(N3)6].
Authors: Haiges Ralf , Boatz Jerry A. , Vij Ashwani , Vij Vandana , Gerken Michael , Schneider Stefan , Schroer Thorsten , Yousufuddin Muhammed , Christe Karl O. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Nickel‐Catalyzed Cross‐Coupling Reaction of Alkyl Halides with Organozinc and Grignard Reagents with 1,3,8,10‐Tetraenes as Additives.
Authors: Terao Jun , Todo Hirohisa , Watanabe Hideyuki , Ikumi Aki , Kambe Nobuaki 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Hexaphyrin(1.0.1.0.0.0). A New Colorimetric Actinoid Sensor.
Authors: Sessler Jonathan L. , Melfi Patricia J. , Seidel Daniel , Gorden Anne E. V. , Ford Doris K. , Palmer Philip D. , Tait C. Drew 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Cu(I)‐Carbenoid‐ and Ag(I)‐Lewis Acid‐Catalyzed Asymmetric Intermolecular Insertion of α‐Diazo Compounds into N—H Bonds.
Authors: Bachmann Stephan , Fielenbach Doris , Joergensen Karl Anker 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
2‐Alkyl‐1,2,3,4‐benzotetrazinium Tetrafluoroborates: Their Reaction with Nucleophiles.
Authors: Lipilin Dmitry L. , Smirnov Oleg Y. , Churakov Aleksandr M. , Strelenko Yuri A. , Tyurin Aleksei Y. , Ioffe Sema L. , Tartakovsky Vladimir A. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
MgI2‐Catalyzed Halo Aldol Reaction: A Practical Approach to (E)‐β‐Iodovinyl‐β′‐hydroxyketones.
Authors: Wei Han‐Xun , Timmons Cody , Farag Mohamed Ali , Pare Paul W. , Li Guigen 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Stereoselective [3,3]‐Sigmatropic Rearrangement Promoted by the Metal [1,3]‐Shift of Binuclear Fischer Carbene Complexes.
Authors: Kamikawa Ken , Tachibana Atsushi , Shimizu Yasunori , Uchida Kazuya , Furusho Masaru , Uemura Motokazu 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Base‐Catalyzed Solution‐Phase Parallel Synthesis of Substituted Vinylic Benzamides from 3‐Amino‐2‐cyclohexanones.
Authors: Anderson Alan J. , Nicholson Jesse M. , Bakare Oladapo , Butcher Ray J. , Scott K. R. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Reactions of Aroyl Chlorides with Samarium Metal in DMF—Controllable Syntheses of O‐Aroylbenzoins, 1,2‐Diarylethanones, and (Z)‐α,α′‐Stilbenediol Dibenzoates.
Authors: Liu Yongjun , Wang Xiaoxia , Zhang Yongmin 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
[3 + 2] and [4 + 2] Cycloadditions of α‐Nitrostyrene with 2‐Hydroxymethyleneindanone and Derivatives
Authors: Hegazi Salaheddine , Titouani Soumia Lafquih , Soufiaoui Mohamed , Tahdi Abderrahim 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
First Stable 7,7,8,8‐Tetraaryl‐o‐quinodimethane: Isolation, X‐Ray Structure, Electrochromic Response of 9,10‐Bis(dianisylmethylene)‐9,10‐dihydrophenanthrene.
Authors: Iwashita Shinichi , Ohta Eisuke , Higuchi Hiroki , Kawai Hidetoshi , Fujiwara Kenshu , Ono Kazunori , Takenaka Masami , Suzuki Takanori 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Sulfonimidamides: Efficient Chiral Iminoiodane Precursors for Diastereoselective Copper‐Catalyzed Arziridination of Olefins.
Authors: Chenna Pablo H. Di , Robert‐Peillard Fabien , Dauban Philippe , Dodd Robert H. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Reaction of C3 and C4 Ketoses with Alkenals and Alkenones in Water.
Authors: Saimoto Hiroyuki , Onitsuka Tomoyuki , Motobe Hironobu , Okabe Satoko , Takamori Yoshimori , Morimoto Minoru , Shigemasa Yoshihiro 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and Pharmacological Activity of 2‐ and 3‐(Aminomethyl)imidazo[1,2‐a]benzimidazoles.
Authors: Anisimova V. A. , Spasov A. A. , Kovalev Yu. G. , Kovalev S. G. , Dudchenko G. P. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and Antifungal Activity Against Strains of Candida albicans of 6‐Fluoro‐4(5 or 7)‐chloro‐2‐(difluorobenzoyl)aminobenzothiazoles.
Authors: Armenise Domenico , De Laurentis Nicolino , Reho Antonia , Rosato Antonio , Morlacchi Flaviano 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Microwave‐Assisted Click Chemistry Synthesis of 1,4‐Disubstituted 1,2,3‐Triazoles via a Copper(I)‐Catalyzed Three‐Component Reaction.
Authors: Appukkuttan Prasad , Dehaen Wim , Fokin Valery V. , Van der Eycken Erik 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Highly Stereoselective Oxy‐Michael Additions to α,β‐Disubstituted Nitro Olefins: Asymmetric Synthesis of Pseudo‐Norephedrine Derivatives and THP* Protected α‐Hydroxy Ketones.
Authors: Buchanan David J. , Dixon Darren J. , Hernandez‐Juan Felix A. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Electrophilic Substitution in the Dihydroquercitin System. Aminomethylation.
Authors: Kukhareva T. S. , Krasnova V. A. , Koroteev M. P. , Kaziev G. Z. , Kuleshova L. N. , Korlyukov A. A. , Antipin M. Yu. , Nifant'ev E. E. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Site‐Selective Monotitanation of Dialkynylpyridines and Its Application for Preparation of Highly Fluorescent π‐Conjugated Oligomers.
Authors: Takayama Yuuki , Hanazawa Takeshi , Andou Tomohiro , Muraoka Kenji , Ohtani Hiroyuki , Takahashi Mizuki , Sato Fumie 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Efficient N‐Arylation of Pyridazin‐3(2H)‐ones.
Authors: Kim Jeum‐Jong , Park Yong‐Dae , Cho Su‐Dong , Kim Ho‐Kyun , Chung Hyun A. , Lee Sang‐Gyeong , Falck J. R. , Yoon Yong‐Jin 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Influence of N(2)‐Substitution in the Alkylation of (4S)‐Alkyl‐2,4‐dihydro‐1H‐pyrazino[2,1‐b]quinazoline‐3,6‐diones.
Authors: Hernandez Fernando , Morales Viviana , Buenadicha Felix L. , Soellhuber Monica , Avendano Carmen 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
One‐Pot Synthesis of Novel 1,2‐Dihydro‐5‐methyl‐spiro[4H‐3,1‐benzoxazine‐2,3′ [3H]‐indol]‐4,2′‐diones.
Authors: Saxena Anjali , Goswami Rajeev , Khanna Pankaj , Bhagat Sunita , Jain Subhash C. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Novel Heterocyclic System — Dihydro‐2H‐1,5,2,4‐dioxadiazine. 2,4‐Dimethyldihydro‐2H‐1,5,2,4‐dioxadiazine Hydrochloride: Synthesis and NMR Study.
Authors: Anikin O. V. , Lipilin D. L. , Belyakov P. A. , Ryabtsev V. Yu. , Tartakovsky V. A. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Nor‐ent‐kaurane Diterpenes and Hydroxylactones from Antennaria geyeri and Anaphalis margaritacea.
Authors: Ahmed Ahmed A. , Hussein Taha A. , Mahmoud Ahmed A. , Farag Mohamed A. , Pare Paul W. , Wojcinska Malgorzata , Karchesy Joe , Mabry Tom J. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Xanthones from a Microfungus of the Genus Xylaria.
Authors: Healy Peter C. , Hocking Ailsa , Tran‐Dinh Nai , Pitt John I. , Shivas Roger G. , Mitchell Jennifer K. , Kotiw Mike , Davis Rohan A. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Novel Series of p38 MAP Kinase Inhibitors for the Potential Treatment of Rheumatoid Arthritis.
Authors: Brown Dearg S. , Belfield Andrew J. , Brown George R. , Campbell Douglas , Foubister Alan , Masters David J. , Pike Kurt G. , Snelson Wendy L. , Wells Stuart L. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Functional food design based on a virtual food component: wheat bran equivalents for faecal bulk
Authors: Monro John A , Martinet Eve 
Published: February 2005

AbstractThis paper reports the first use of a virtual food component (VFC), which is a value that represents the functional efficacy of a food in the format of a food component, to accurately formulate a functional food and evaluate its efficacy. The effect measured was faecal bulking and the functional food was a cereal bar. The faecal bulking efficacy of ingredients was determined as their content of the VFC, wheat bran equivalents for faecal bulk (WBEfb), which represents faecal bulking efficacy expressed in terms of the amount of wheat bran that would produce an equivalent effect. Using a validated animal model, we measured the faecal bulking efficacy of cereal bar ingredients individually and after combining them in a cereal bar recipe, before and after the combined ingredients had been baked. The sum of the WBEfb contents of the ingredients was 29.7 WBEfb per bar (SEM 2.4). The WBEfb of the recipe mixture before baking was 33.2 WBEfb per bar (SEM 2.4) and after baking was 28.5 WBEfb per bar (SEM 2.9). Faecal bulking efficacy was not related to dietary fibre content. We conclude that the WBEfb content of ingredients can be used to design cereal bars of specified faecal bulking efficacy and that the functionality is resistant to baking. Copyright © 2005 Society of Chemical Industry
Potential protein degradation balance and total metabolizable protein supply to dairy cows from heat‐treated faba beans
Authors: Yu P 
Published: February 2005

AbstractThe effects of pressure toasting (100, 118 and 136 °C for 3, 7, 15 and 30 min) on potential protein nutritional value of faba beans were evaluated with the NRC 2001 dairy model, by determining undegraded (RUP) and degraded rumen protein (RDP), undegraded (RUST) and degraded rumen starch (RDST), truly absorbed undegraded protein (ARUP), microbial protein (MCPRDP) synthesized in the rumen from rumen‐available protein, truly absorbed rumen synthesized microbial protein (AMCP), truly absorbed rumen endogenous protein (AECP), total metabolizable protein (MP) in the small intestine, and the protein degradation balance (PDB). The treatments increased RUP, RUST, ARUP and MP (p < 0.001), and decreased RDP, RDST, MCPRDP and PDB (p < 0.001), the effects increasing with increasing temperature and time. The treatments increased (p < 0.001) ARUP without affecting AECP and AMCP, so that the net absorbable total MP in the small intestine was increased. The PDB was reduced (p < 0.001) but never became negative. These results indicated that potential microbial protein synthesis would not be impaired due to sufficient nitrogen in the rumen, but the high positive PDB values with most treatments, except 136 °C for 15 min (PDB 2.0 g kg−1 DM) indicated that there were large potential losses of nitrogen in the rumen, particularly for the control with a value of 88.9 g kg−1 dry matter. It is concluded that predicted potential protein degradation balance and total metabolizable protein supply from faba beans were improved by the treatments. Copyright © 2005 Society of Chemical Industry
Microstructural, cooking and textural characteristics of potato (Solanum tuberosum L) tubers in relation to physicochemical and functional properties of their flours
Authors: Singh Narpinder , Kaur Lovedeep , Ezekiel Rajaranganathan , Singh Guraya Harmeet 
Published: February 2005

AbstractPotato tubers from six different cultivars were freeze‐dried, ground into flour and analyzed for thermal, pasting and textural characteristics (using differential scanning calorimetry, Rapid Visco analyzer and Instron universal testing machine, respectively) to study the relationship between flour characteristics and cooked potato mealiness. The potatoes with higher sensory mealiness scores resulted in flours having lower transition and pasting temperatures, higher amylose content, setback, peak and final viscosity. The flour gels from the mealier potatoes also exhibited higher values of textural parameters such as hardness, cohesiveness, chewiness and springiness. The microstructure of the tuber parenchyma (studied using scanning electron microscopy), cooking and sensory characteristics of potatoes were found to be related to the pasting and textural characteristics of their flours. Potato cultivars with lower mealiness scores, loosely packed cell arrangement, with comparatively large‐size cells and thinner cell walls showed lower values of textural parameters for both raw and cooked potatoes. This information may prove useful for the selection of potato cultivars with desirable textural and flour‐making properties for specific end‐uses. Copyright © 2005 Society of Chemical Industry