bluuebunny/crossref_metadata_2025_split huggingface dataset:
4‐Aminothiourea Prolinol tert‐Butyldiphenylsilyl Ether: A Chiral Secondary Amine‐Thiourea as Organocatalyst for Enantioselective anti‐Mannich Reactions
Authors: Zhang Hui , Chuan Yongming , Li Zhengyu , Peng Yungui 
Published: October 2009

Abstractanti‐Selective Mannich reactions of N‐p‐methoxyphenyl (PMP)‐protected α‐iminoglyoxylate with unmodified aldehydes or ketones were effectively catalyzed by 4‐aminothiourea prolinol tert‐butyldiphenylsilyl ether. The reactions led to chiral β‐amino carbonyl compounds in high yields (up to 94%), excellent diastereo‐ and enantioselectivities (up to 98% de and >99% ee). The study demonstrated for the first time that direct Mannich‐type reactions of unmodified aldehydes or ketones to α‐iminoglyoxylate can be promoted by secondary amine‐thiourea chiral organocatalyst.
Gold Catalysis: Efficient 1,3‐Induction with Diastereotopic Homopropargyl Alcohols in the Phenol Synthesis
Authors: Hashmi A. Stephen K. , Hamzić Melissa , Rudolph Matthias , Ackermann Martin , Rominger Frank 
Published: October 2009

AbstractFurans with diastereotopic alkynyl groups were prepared and then converted to anellated phenols in gold‐catalyzed reactions. In all cases a highly diastereoselective reaction was observed. The stereochemical outcome of the 1,3‐induction could be assigned by two independent crystal structure analyses, showing a cis‐arrangement of the two alkyl substituents on the benzoanellated cyclohexene ring.
A Novel Proline‐Valinol Thioamide Small Organic Molecule for a Highly Enantioselective Direct Aldol Reaction
Authors: Wang Bing , Chen Guo‐hong , Liu Ling‐yan , Chang Wei‐xing , Li Jing 
Published: October 2009

AbstractA new prolinethioamide compound 4, prepared from readily available natural amino acid L‐proline and amino alcohol L‐valinol, has been found to be an active catalyst for the direct aldol reaction of various aldehydes with acetone, cyclohexanone or cyclopentanone at 0 °C. Using only 2 mol% loading of this organocatalyst, the reaction could give high enantioselectivity with up to 96% enantiomeric excess for the reaction of 2‐nitrobenzaldehyde with acetone. And as for the cyclohexanone, the excellent diastereoselectivity (anti/syn: 99/1) and enantioselectivity (99% ee) could be achieved when reacted with 3‐nitrobenzaldehyde in water in the presence of this thioamide 4. This structurally simple catalyst is a highly efficient prolinethioamide derivative, and the terminal hydroxy group in this catalyst is a primary alcohol which is different from the previously reported prerequisite secondary or tertiary alcohol of prolinamides. Our results suggest a new strategy in the design of diversiform organic catalysts for direct asymmetric aldol reactions and related transformations.
Tandem Enzyme/Gold‐Catalysis: From Racemic α‐Allenic Acetates to Enantiomerically Enriched 2,5‐Dihydrofurans in One Pot
Authors: Asikainen Martta , Krause Norbert 
Published: October 2009

AbstractWe report the first example of a tandem kinetic resolution/cycloisomerization of racemic allenic acetates in the presence of Burkholderia cepacia lipase (PS Amano SD) and catalytic amounts of chloroauric acid (HAuCl4) which affords 2,5‐dihydrofurans, as well as unreacted starting material, in one pot with high enantiomeric excess and moderate to good yield.
Synthesis of (E)‐3‐Alkylidene‐1‐pyrrolines by the Rhodium‐ Catalyzed Cyclization of Terminal Alkynes with Homopropargylic Amines
Authors: Fukumoto Yoshiya , Kawahara Takuya , Kanazawa Yukinori , Chatani Naoto 
Published: October 2009

AbstractThe cyclization of terminal alkynes with homopropargylic amines in the presence of a rhodium complex as catalyst leads to the formation of (E)‐3‐alkylidene‐1‐pyrrolines. The reaction tolerates a wide range of functional groups on the terminal alkynes. The formation of a vinylidene‐rhodium complex, followed by the intermolecular nucleophilic attack of a homopropargylic amine nitrogen on the α‐carbon atom of the vinylidene‐rhodium complex, is proposed as a key step in the catalytic reaction.
Iron(III)‐Catalyzed Intramolecular Friedel–Crafts Alkylation of Electron‐Deficient Arenes with π‐Activated Alcohols
Authors: Bandini Marco , Tragni Michele , Umani‐Ronchi Achille 
Published: October 2009

Abstract“Deficient” but “efficient”, the first example of a catalytic Friedel–Crafts alkylation of arenes, carrying electron‐withdrawing groups, with alcohols is reported. The optimized iron(III) chloride (97%) catalyzed allylation, benzylation and propargylation procedures open an access to a range of tetrahydronaphthalenes, tetrahydroisoquinolines and tetrahydrobenzo[d]azepines featuring tertiary benzylic stereocenters in excellent yields (up to 92%) and short reaction times.
Register data suggest lower intelligence in men born the year after flu pandemic
Authors: Eriksen Willy , Sundet Jon M. , Tambs Kristian 
Published: October 2009

AbstractObjectiveTo test the hypothesis that prenatal exposure to the Hong Kong flu, an influenza pandemic that haunted Europe during winter 1969 to 1970, was associated with reduced intelligence in adulthood.MethodsData from the Medical Birth Register of Norway were linked with register data from the National Conscript Service. The sample comprised all registered boys born alive in single birth after 37 to 43 weeks' gestation during 1967 to 1973 (n = 205,634). Intelligence test scores, recorded at military conscription, were available for 182,913 individuals.ResultsThe mean intelligence score increased from one birth year to another, except for a downturn in 1970. The birth year 1970 was inversely associated with intelligence score (−0.03 standard deviation [SD]; p < 0.001) after adjustments for birth characteristics, parental characteristics, and the trend of increasing scores over the 7 birth years. Analyses with the sample stratified by birth month showed that the inverse association between the birth year 1970 and intelligence score was significant only among men born in July (−0.04 SD; p = 0.049), August (−0.05 SD; p = 0.013), September (−0.09 SD; p < 0.001), and October (−0.06 SD; p = 0.008). Thus, the intelligence scores of the men born 6 to 9 months after the epidemic were lower than the mean values for the men born in the same months a few years before or after.InterpretationEarly prenatal exposure to the Hong Kong flu may have interfered with fetal cerebral development and caused reduced intelligence in adulthood. Ann Neurol 2009;66:284–289
Polymere Janus‐Partikel
Authors: Wurm Frederik , Kilbinger Andreas F. M. 
Published: October 2009

AbstractSeit de Gennes in seinem Nobelvortrag im Jahr 1991 den Begriff “Janus‐Partikel” prägte, ist die Forschung an solchen asymmetrischen Partikeln entbrannt. Hierbei unterscheidet man makroskopische, mikroskopische und nanoskopische Partikel, deren Oberfläche in chemischer Zusammensetzung, Polarität, Farbe oder einer anderen Eigenschaft inhomogen gestaltet ist. Sowohl sphärische, zylindrische und scheibenförmige Strukturen als auch solche mit Schneemann‐, Hamburger‐ oder Himbeer‐Form auf der Basis von organischen, anorganischen oder Hybridmaterialien wurden detailliert untersucht. Die Synthesestrategien für solche Partikel reichen von einfachen Polymermischungen über Mikrophasentrennung von Terblockpolymeren in Substanz bis hin zu Immobilisierungsmethoden ausgehend von symmetrischen Partikeln. Polymere Janus‐Partikel im Speziellen sind wegen ihrer kostengünstigen und oft hochskalierbaren Synthese vielversprechende Kandidaten für Anwendungen in vielen Bereichen.
Innervation Patterns of the Canine Masticatory Muscles in Comparison to Human
Authors: Yang Hun‐Mu , Hu Kyung‐Seok , Song Woo‐Chul , Park Jong‐Tae , Kim Heung‐Joong , Koh Ki‐Seok , Kim Hee‐Jin 
Published: October 2009

AbstractThe aim of this study was to clarify the nerve distribution of the masseter, temporalis, and zygomaticomandibularis (ZM) muscles to elucidate the phylogenetic traits of canine mastication. A detailed dissection was made of 15 hemisectioned heads of adult beagle dogs. The innervations of the masticatory nerve twigs exhibited a characteristic pattern and were classified into seven groups. Twig innervating the anterior portion of the temporalis (aTM) was defined as the anterior temporal nerve (ATN). Anterior twig of ATN branched from the buccal nerve and innervated only the aTM, whereas posterior twig of ATN innervated both of the aTM and deep layer of the tempolaris (dTM). From this and morphological observations, it was proposed that the action of the canine aTM is more independent than that of the human. The middle temporal nerve ran superoposteriorly within the dTM and superficial layer of the temporalis (sTM) innervating both of them, whereas the posterior temporal nerve innervated only the posterior region of the sTM. The masseteric nerve (MSN) innervated the ZM and the three layers of the masseter. Deep twig of MSN was also observed innervating sTM after entering the ZM in all cases. The major role played by the canine ZM might thus underlie the differential arrangement of the distribution of the masticatory nerve bundles in dogs and humans. Although the patterns of innervation to the canine and human masticatory muscles were somewhat similar, there were some differences that might be due to evolutionary adaptation to their respective feeding styles. Anat Rec, 2010. © 2009 Wiley‐Liss, Inc.
The Maxillary Sinus in Three Genera of New World Monkeys: Factors That Constrain Secondary Pneumatization
Authors: Smith Timothy D. , Rossie James B. , Cooper Gregory M. , Carmody Kelly A. , Schmieg Robin M. , Bonar Christopher J. , Mooney Mark P. , Siegel Michael I. 
Published: October 2009

AbstractThe air filled cavities of paranasal sinuses are thought by some to appear opportunistically in spatial “gaps” within the craniofacial complex. Anthropoid primates provide excellent natural experiments for testing this model, since not all species possess a full complement of paranasal sinuses. In this study, two genera of monkeys (Saguinus and Cebuella) which form maxillary sinuses (MS) as adults were compared to squirrel monkeys (Saimiri spp.), in which a MS does not form. Using microCT and histomorphometric methods, the spatial position of paranasal spaces was assessed and size of the adjacent dental sacs was measured. In Saguinus, secondary pneumatization is underway perinatally, and the sinus extends alongside deciduous premolars (dp). The MS overlaps all permanent molars in the adult. In Saimiri, the homologous space (maxillary recess) extends no farther posterior than the first deciduous premolar at birth and extends no farther than the last premolar in the adult. Differences in dental size and position may account for this finding. For example, Saimiri has significantly larger relative dp volumes, and enlarged orbits, which encroach on the internasal space to a greater degree when compared to Saguinus. These factors limit space for posterior expansion of the maxillary recess. These findings support the hypothesis that secondary pneumatization is a novel, opportunistic growth mechanism that removes “unneeded” bone. Moreover, paranasal spaces occur in association with semiautonomous skeletal elements that border more than one functional matrix, and the spatial dynamics of these units can act as a constraint on pneumatic expansion of paranasal spaces. Anat Rec, 2010. © 2009 Wiley‐Liss, Inc.
Geophysical study of a Pre‐Hispanic lakeshore settlement, Chiconahuapan Lake, Mexico
Authors: Chávez R. E. , Tejero A. , Argote D. L. , Cámara M. E. 
Published: October 2009

AbstractResults of a combined geophysical survey carried out along the northern shore of Lake Chiconahuapan in central Mexico are presented. The site contains a series of mounds found between the lakeshore and the ceremonial centre named La Campana‐Tepozoco Hill. Those features are the remains of habitation complexes built by the lake residents about 1100 years ago. Archaeological excavations performed towards the northeastern margins of the lake uncovered rectangular clusters of basaltic rocks forming the foundations of ancient dwellings, surrounded by a barrier (‘bordo’), built to prevent floods. A mound located close to the ceremonial centre was studied using the vertical magnetic gradient (VMG), ground‐penetrating radar (GPR) and electric tomography (ET) methods. Interesting magnetic anomalies were found towards the central portion of the mound and one of these was modelled with a three‐dimensional magnetic polygon. The GPR studies unveiled a circular feature in the central portion of the mound that could be associated with a bordo. A rectangular structure was also interpreted within the limits of that structure, which is probably the location of ancient dwelling foundations. Electric tomography profiles were collected in the area, around the VMG anomaly. The resistivity model computed shows the presence of a high‐resistivity layer, which displays discontinuities within the area defined by the bordo. Presumably, the ancient settlers built their constructions on top of this horizon. The geophysical results reveal a rather complex habitat within the mound. The larger size of the bordo (ca. 30 m in diameter) compared with others already studied by archaeologists makes us believe that the purpose of the site was of administrative use or hosted a wealthy group of people. Dwelling foundations are found within the limits of the barrier. Copyright © 2009 John Wiley & Sons, Ltd.
Suzuki Cross‐Coupling Reactions Catalyzed by an Aliphatic Phosphine‐Based Pincer Complex of Palladium: Evidence for a Molecular Mechanism
Authors: Gerber Roman , Blacque Olivier , Frech Christian M. 
Published: October 2009

AbstractA new phosphine‐based pincer complex with an adamantyl core, [{C10H13‐1,3‐(CH2PCy2)2}Pd(Cl)] (1), has proved to be an excellent Suzuki catalyst. Catalyst 1 enables the quantitative coupling of a wide variety of electronically activated, deactivated, and/or sterically hindered and highly functionalized aryl bromides with phenylboronic acid in pure water with NaOH as base within very short reaction times and low catalyst loadings and without the need for exclusion of air. Hydrophobic substrates, which lead to inefficient conversions in aqueous solution, are efficiently and quantitatively coupled by 1 in toluene with K3PO4 as base. Mechanistic investigations indicate that palladium nanoparticles are probably not the catalytically active form of 1. Experimental results strongly indicate that the phenyl pincer complex [{C10H13‐1,3‐(CH2PCy2)2}Pd(Ph)] (3) is a key intermediate in the catalytic cycle of the Suzuki reaction in both toluene and aqueous solution. Treatment of 1 with phenylboronic acid exclusively yields 3 under catalytic reaction conditions. Moreover, stoichiometric reactions of 3 with aryl bromides lead to the exclusive formation of [{C10H13‐1,3‐(CH2PCy2)2}Pd(Br)] (2) and the corresponding biaryl, thus indicating that biaryl formation occurs either by oxidative addition of aryl bromides to 3, to form neutral hexacoordinated pincer‐type PdIV intermediates with the general formula of [{C10H13‐1,3‐(CH2PCy2)2}Pd(Ar)(Br)(Ph)], followed by reductive elimination of the coupling products or by direct biaryl formation on the PdII center of 3, via a four‐centered transition state.
Synthetic Mimics of Antimicrobial Peptides—A Versatile Ring‐Opening Metathesis Polymerization Based Platform for the Synthesis of Selective Antibacterial and Cell‐Penetrating Polymers
Authors: Lienkamp Karen , Tew Gregory N. 
Published: October 2009

AbstractNatural macromolecules exhibit an extensive arsenal of properties, many of which have proven difficult to recapitulate in simpler synthetic systems. Over the last couple of years, foldamers have emerged as one important step toward increased functionality in synthetic systems. While the great majority of work in this area has focused on folded structures, hence the name, more recent progress has centered on polymers that mimic protein function. These efforts have resulted in the design of relatively simple macromolecules; one example are the synthetic mimics of antimicrobial peptides (SMAMPs) that capture the central physicochemical features of their natural archetypes irrespective of the specific folded form. Here we present our recent efforts to create polymers which display biological activity similar to natural proteins, including antimicrobial and cell‐penetrating peptides.
Antimicrobial Polymers Prepared by Ring‐Opening Metathesis Polymerization: Manipulating Antimicrobial Properties by Organic Counterion and Charge Density Variation
Authors: Lienkamp Karen , Madkour Ahmad E. , Kumar Kushi‐Nidhi , Nüsslein Klaus , Tew Gregory N. 
Published: October 2009

AbstractThe synthesis and characterization of a series of poly(oxanorbornene)‐based synthetic mimics of antimicrobial peptides (SMAMPs) is presented. In the first part, the effect of different organic counterions on the antimicrobial properties of the SMAMPs was investigated. Unexpectedly, adding hydrophobicity by complete anion exchange did not increase the SMAMPs’ antimicrobial activity. It was found by dye‐leakage studies that this was due to the loss of membrane activity of these polymers caused by the formation of tight ion pairs between the organic counterions and the polymer backbone. In the second part, the effect of molecular charge density on the biological properties of a SMAMP was investigated. The results suggest that, above a certain charge threshold, neither minimum inhibitory concentration (MIC90) nor hemolytic activity (HC50) is greatly affected by adding more cationic groups to the molecule. A SMAMP with an MIC90 of 4 μg mL−1 against Staphylococcus aureus and a selectivity (=HC50/MIC90) of 650 was discovered, the most selective SMAMP to date.
Organocatalytic Asymmetric Aza‐Michael Additions
Authors: Enders Dieter , Wang Chuan , Liebich Jens X. 
Published: October 2009

AbstractThe catalytic aza‐Michael addition is an important reaction within synthetic organic chemistry, given the significance of the biologically and synthetically interesting products, such as β‐amino acids and β‐lactams. In the last decade organocatalysis emerged as a powerful tool in asymmetric synthesis and had a large impact on the development of asymmetric and catalytic conjugate additions of nitrogen nucleophiles to Michael acceptors. In this review a first summary of the recent rapid progress of asymmetric organocatalyzed aza‐Michael reactions is presented.
ChemInform Abstract: Structural, Vibrational and Thermodynamics Properties of Zn‐Based Semiconductors
Authors: Yu Y. , Han H. L. , Wan M. J. , Cai T. , Gao T. 
Published: October 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Reinvestigation of Sr2[Cu(OH)6].
Authors: Sutovic Sabina , Karanovic Ljiljana , Poleti Dejan 
Published: October 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal Growth, Structure, and Physical Properties of Ln(Cu,Ga)13‐x (Ln: La—Nd, Eu; x ≈ 0.2).
Authors: Cho Jung Young , Thomas Evan L. , Nambu Yusuke , Capan Cigdem , Karki Amar B. , Young David P. , Kuga Kentarou , Nakatsuji Satoru , Chan Julia Y. 
Published: October 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal Structures, Site Occupations and Phase Equilibria in the System V—Zr—Ge.
Authors: Marker Martin C. J. , Effenberger Herta S. , Richter Klaus W. 
Published: October 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Structure, Conductivity, and Thermal Expansion Studies of Redox Stable Rutile Niobium Chromium Titanates in Oxidizing and Reducing Conditions.
Authors: Lashtabeg Anna , Canales‐Vazquez Jesus , Irvine John T. S. , Bradley John L. 
Published: October 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Oxidation of Carbon Monoxide Cocatalyzed by Palladium(0) and the H5PV2Mo10O40 Polyoxometalate Probed by Electron Paramagnetic Resonance and Aerobic Catalysis.
Authors: Goldberg Hila , Kaminker Ilia , Goldfarb Daniella , Neumann Ronny 
Published: October 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: [CrBr2(NH3)4] [CrBr4(NH3)2], a New Chromium(III) Complex.
Authors: Stork Ludwig , Liu Xiaohui , Fokwa Boniface P. T. , Dronskowski Richard 
Published: October 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Heteropoly‐13‐Palladates(II) [Pd13II(AsVPh)8O32] 6‐ and [Pd13IISe8IVO32] 6‐.
Authors: Izarova Natakya V. , Dickman Michael H. , Biboum Rosa Ngo , Keita Bineta , Nadjo Louis , Ramachandra Vasanth , Dalal Naresh S. , Kortz Ulrich 
Published: October 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Combined Action of Enzymes: The First Domino Reaction Catalyzed by Agaricus bisporus.
Authors: Leutbecher Heiko , Hajdok Szilvia , Braunberger Christina , Neumann Melanie , Mika Sabine , Conrad Juergen , Beifuss Uwe 
Published: October 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Furans versus 4H‐Pyrans: Catalyst‐Controlled Regiodivergent Tandem Michael Addition—Cyclization Reaction of 2‐(1‐Alkynyl)‐2‐alken‐1‐ones with 1,3‐Dicarbonyl Compounds.
Authors: Xiao Yuanjing , Zhang Junliang 
Published: October 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.