bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Photochemical Transformations. Part 45. Orbital Overlap Preferences in Excited‐State Intramolecular Electron Transfers.
Authors: CRISTOL S. J. , AELING E. O. , HENG R. 
Published: May 2016

AbstractThe dibenzobicyclooctadiene (I), prepared as the Diels‐Alder adduct of 2‐methoxyanthracene and cis‐1,2‐dichloroethene, forms the acetates (II) by Ag+ promoted acetolysis via Wagner‐Meerwein rearrangements.
ChemInform Abstract: α,β‐Epoxy Sulfoxides as Useful Intermediates in Organic Synthesis. Part 9. A Novel Synthesis of Alkyl Vinyl Ketones and Divinyl Ketones from Carbonyl Compounds and 1‐Chloro‐3‐phenylthiopropyl Phenyl Sulfoxide as a Three‐Carbon Homologating Agent.
Authors: SATOH T. , KUMAGAWA T. , SUGIMOTO A. , YAMAKAWA K. 
Published: May 2016

AbstractThe epoxy sulfoxides (I) are converted to the alkyl vinyl ketones (III) via the phenylthio carbonyl compounds (II).
ChemInform Abstract: Transition Metal Catalyzed Reaction of Me3SiCN. Part 4. Palladium‐Catalyzed Cyanation of Aryl Halides by Trimethylsilyl Cyanide.
Authors: CHATANI N. , HANAFUSA T. 
Published: May 2016

AbstractReaction of the aryl iodides (I) with trimethylsilyl cyanide (II) in the presence of catalytic amounts of the palladium complex (III) yields the aryl cyanides (IV).
ChemInform Abstract: Synthesis and Antitumor Activity of Tropolone Derivatives. Part 4.
Authors: YAMATO M. , HASHIGAKI K. , SAKAI J. , KAWASAKI Y. , TSUKAGOSHI S. , TASHIRO T. 
Published: May 2016

AbstractCondensation of hinokitiol (I) with p‐anisaldehyde diethyl acetal (II) yields the tropolone derivative (III) which reacts with various nucleophiles (IV) to give the pseudobistropolones (V).
ChemInform Abstract: Polyspiranes. Part 12. Cascade Rearrangements. Part 7. Heptacyclo(19.3.0.01,5.05,9.09,13.013,17.017,21)tetracosane ((6.5)Coronane).
Authors: WEHLE D. , FITJER L. 
Published: May 2016

AbstractGrignard reaction of (I) followed by cascade rearrangement affords the hexacyclic diene (II), which is converted to the bromide (III).
ChemInform Abstract: Chiral Michael Addition: Methyl Vinyl Ketone Addition Catalyzed by Cinchona Alkaloid Derivatives.
Authors: CONN R. S. E. , LOVELL A. V. , KARADY S. , WEINSTOCK L. M. 
Published: May 2016

AbstractAddition of methyl vinyl ketone (V) to the indanone (III) in the presence of the cinchoninium salt (I) yields the enantiomer S‐(IV).
ChemInform Abstract: A Stereoselective Synthesis of D‐Normorphinan Derivatives by Means of an Intramolecular Diels‐Alder Reaction.
Authors: KAMETANI T. , SUZUKI Y. , HONDA T. 
Published: May 2016

AbstractIntramolecular thermal cycloaddition reaction of the benzocyclobutenes (I) yields the hydrophenanthrenes (II) ‐ (VI) which are valuable synthons for the preparation of D‐normorphinan derivatives.
ChemInform Abstract: Furo(3,2‐b)indole Derivatives. Part 6. Synthesis and Inhibitory Effect on Platelet Aggregation of Furo(3,2‐b)indole Derivatives.
Authors: KAWASHIMA Y. , HOSODA K. , GOTO J. , SATO M. , HATADA Y. , ASAMI Y. , NAKASHIMA Y. , SOTA K. 
Published: May 2016

AbstractThe bis(hydroxyethyl)aminomethylfuro(3,2‐b)indoles (II) are prepared as shown in the reaction scheme.
ChemInform Abstract: Synthesis of 4(5)‐Alkylimidazolinones‐2.
Authors: ZAV'YALOV S. I. , DOROFEEVA O. V. , TAGANOVA O. K. 
Published: May 2016

AbstractIn mixtures of the bromoketones (I) and (II), the bromomethyl compounds (I) react selectively with amines such as piperidine (III) or trimethylamine (V) to give the corresponding aminomethyl ketones (IV) and (VI) respectively.
ChemInform Abstract: Cycloaddition Reaction of 2,3‐Disubstituted Oxiranes with Isocyanates by Highly Activated Catalyst; Ph4SbI‐Bu3SnI.
Authors: FUJIWARA M. , BABA A. , TOMOHISA Y. , MATSUDA H. 
Published: May 2016

AbstractThe oxiranes (I) are coupled with the isocyanates (II) in the presence of the catalyst system (III) to yield the oxazolidinones (IV).
ChemInform Abstract: Pummerer Reaction of 3‐Sulfinylmethyl‐4,5‐dihydroisoxazoles: A New Synthesis of Protected 3‐Formyl‐4,5‐dihydroisoxazoles.
Authors: COZZI F. , GOBBI C. , RAIMONDI L. , RESTELLI A. 
Published: May 2016

AbstractThe two‐step synthesis of the dimethylacetals (III) is described.
ChemInform Abstract: Reaction of 3‐Aminofurazanes with Elemental Fluorine.
Authors: FOKIN A. V. , TSELINSKII I. V. , MEL'NIKOVA S. F. , VERGIZOV S. N. , STUDNEV YU. N. , STOLYAROV V. P. , IL'IN S. S. 
Published: May 2016

AbstractThe aminofurazanes (I) react with elemental fluorine to give the difluoroamino compounds (II).
ChemInform Abstract: Nitriles in Organic Synthesis: A New Synthesis of 3,5‐Diarylbenzene Derivatives.
Authors: EL‐TORGOMAN A. M. , HAFEZ E. A. A. , EL‐KOUSY S. M. , ELNAGDI M. H. 
Published: May 2016

AbstractThe ethylidenemalodinitrile (I) reacts with the thioamides (II) to yield the diaryldicyanobenzenes (III).
ChemInform Abstract: Synthesis of Heterocycles via Enamines. Part 12. Intramolecular Additions of Nucleophiles to 1,4‐Dihydropyrimidine‐2(3H)‐thione Derivatives: Single‐Step Synthesis of Condensed Heterocyclic Compounds.
Authors: SINGH H. , KUMAR S. 
Published: May 2016

AbstractReaction of the isothiocyanates (I) with the amines (II) bearing a second nucleophile gives the heterobicycles (III).
ChemInform Abstract: Nucleophilic Addition Reactions of Hindered Unsaturated Boranes. A New Synthesis of Organoboranes.
Authors: COOKE M. P. JUN. , WIDENER R. K. 
Published: May 2016

AbstractVinylboranes (I) and (VII), bearing the bulky mesityl substituents to preclude ate complex formation, undergo nucleophilic addition on reaction with organolithium compounds (II).
ChemInform Abstract: Chiral Synthesis via Organoboranes. Part 9. Crystalline “Chelates” from Borinic and Boronic Esters. A Simple Procedure for Upgrading Borinates and Boronates to Materials Approaching 100% Optical Purity.
Authors: BROWN H. C. , PRASAD J. V. N. V. 
Published: May 2016

AbstractThe borinate (I) forms the 1:1‐complex (III) on reaction with the amino alcohol (II).
ChemInform Abstract: Attempted Synthesis of Selenium and Tellurium Analogs of 1,5‐Diaryl‐ 1,3,5‐trithia‐2,4‐diaza‐2,3‐pentadienes.
Authors: ZIBAREV A. V. , KONCHENKO S. N. , FURIN G. G. , FEDOTOV M. A. 
Published: May 2016

AbstractThe trithia‐ and thiadiselenadiazaallenes (III) are prepared from the bistrimethylsilyl compound (II) and the chlorides (Ia) ‐ (Ic).
ChemInform Abstract: X‐Ray Crystal Structure Analysis of Deacetyldehydroeuphorianin: The Correct Structure of the Novel Pentacyclic Macrocyclic Diterpene, Euphorianin.
Authors: OKOGUN J. I. , FAKUNLE C. O. , EKONG D. E. U. , LINDNER H. J. , HABERMEHL G. G. 
Published: May 2016

AbstractEuphorianin, isolated from Euphorbia poisonii, is hydrolyzed and oxidized to give the product (II).
ChemInform Abstract: Preparation of Aromatase Inhibitors. Synthesis of 19,19‐Difluoro‐4‐hydroxyandrost‐4‐ene‐3,17‐dione and Related Compounds.
Authors: MANN J. , PIETRZAK B. 
Published: May 2016

AbstractThe steroid (IIIa) is synthesized from the androstene derivative (Ia) via (Ib) and (Ic), while the title 4‐hydroxy compound (IIIb) is obtained from (IIIa) via epoxidation, ring opening with methanolic NaOH and cleavage of the resulting methoxy group.
ChemInform Abstract: Chiral Synthons for the Total Synthesis of Fluoro Amino Acids and Fluoro Analogues of Antibiotic Sugars.
Authors: FAGHIH R. , CABRERA ESCRIBANO F. , CASTILLON S. , GARCIA J. , LUKACS G. , OLESKER A. , THANG T.‐T. 
Published: May 2016

AbstractThe 2‐fluoro‐3‐azido sugars (II), (V), and (VII) and the 2‐azido‐3‐ fluoro sugars (VIIIb), (XII), and (XIIIb) are prepared as chiral synthons for fluoro amino sugars and fluoro amino acids.
ChemInform Abstract: Reactivity of N‐Imidazolylsulfonates at C‐2 of α‐D‐Manno‐ and ‐Galactopyranosides.
Authors: EL SAYED AHMED F. M. , DAVID S. , VETELE J.‐M. 
Published: May 2016

AbstractThe mannopyranosides (I), the galactopyranosides (IV) and (VIIIa), and the lactose derivative (Xa) are converted into their N‐imidazolyl sulfonyl derivatives (II), (V), (VIIIb), and (Xb) respectively.
ChemInform Abstract: Syntheses of Heterocyclic Compounds Containing Benzopyrone. Part 5. Total Synthesis of Fulvic Acid.
Authors: YAMAUCHI M. , KATAYAMA S. , TODOROKI K. , WATANABE T. 
Published: May 2016

AbstractThe total synthesis of the fungal metabolite fulvic acid (VIII) starts from the acetophenone (I) which in turn is obtained from vanillin via 9 steps (38% total yield).
ChemInform Abstract: Preparation of Ceph‐3‐em Esters Unaccompanied by δ3 → δ2 Isomerization of the Cephalosporin.
Authors: MOBASHERY S. , JOHNSTON M. 
Published: May 2016

AbstractDirect alkylation of the 3‐cephemcarboxylates (I) with the alkyl bromides (II) gives almost exclusively the 3‐cephem esters (III), when a solvent mixture of DMF and dioxane is used.
ChemInform Abstract: New Methylseleno‐Promoted Ketene‐Imine Cycloaddition Reaction. A Simplified Stereoselective Synthesis of Penam.
Authors: NAGAO Y. , KUMAGAI T. , TAKAO S. , ABE T. , OCHIAI M. , INOUE Y. , TAGA T. , FUJITA E. 
Published: May 2016

AbstractThe alkoxyketenes (I), formed in situ from the corresponding alkoxyacetyl chlorides and triethylamine, react with the methylselenothiazolines (II) to produce the methylselenopenams (IIIa) stereoselectively.
How Electronic Excitation Can be Used to Inhibit Some Mechanisms Associated to Substituent Effects
Authors: Ferro‐Costas David , Francisco Evelio , Martín Pendás Ángel , Mosquera Ricardo A. 
Published: May 2016

AbstractDespite the fact that transferability and chemistry go hand in hand, transferability studies in electronically excited states (EESs) are normally omitted, although these states are becoming extremely important in modern processes and applications. In this work, it is shown that this kind of studies can be used to understand how substituent effects can be modified in EESs. Thus, for example, the analysis of the carbonyl oxygen transferability in different HCO‐R molecules allowed us to find that the
excitation can be used to break the π conjugation associated to the resonance substituent effect. Moreover, as a direct consequence, the oxygen transferability is enhanced in the first electronically excited state.
From Sugars to Wheels: The Conversion of Ethanol to 1,3‐Butadiene over Metal‐Promoted Magnesia‐Silicate Catalysts
Authors: Shylesh Sankaranarayanapillai , Gokhale Amit A. , Scown Corinne D. , Kim Daeyoup , Ho Christopher R. , Bell Alexis T. 
Published: May 2016

Abstract1,3‐Butadiene (1,3‐BD) is a high‐value chemical intermediate used mainly as a monomer for the production of synthetic rubbers. The ability to source 1,3‐BD from biomass is of considerable current interest because it offers the potential to reduce the life‐cycle greenhouse gas (GHG) impact associated with 1,3‐BD production from petroleum‐derived naphtha. Herein, we report the development and investigation of a new catalyst and process for the one‐step conversion of ethanol to 1,3‐BD. The catalyst is prepared by the incipient impregnation of magnesium oxide onto a silica support followed by the deposition of Au nanoparticles by deposition–precipitation. The resulting Au/MgO‐SiO2 catalyst exhibits a high activity and selectivity to 1,3‐BD and low selectivities to diethyl ether, ethylene, and butenes. Detailed characterization of the catalyst shows that the desirable activity and selectivity of Au/MgO‐SiO2 are a consequence of a critical balance between the acidic–basic sites associated with a magnesium silicate hydrate phase and the redox properties of the Au nanoparticles. A process for the conversion of ethanol to 1,3‐BD, which uses our catalyst, is proposed and analyzed to determine the life‐cycle GHG impact of the production of this product from biomass‐derived ethanol. We show that 1,3‐BD produced by our process can reduce GHG emissions by as much as 155 % relative to the conventional petroleum‐based production of 1,3‐BD.
Inducing optimal substitution between antibiotics under open access to the resource of antibiotic susceptibility
Authors: Herrmann Markus , Nkuiya Bruno 
Published: May 2016

SummaryThis paper designs a bio‐economic model to examine the use of substitute antibiotic drugs (analogs) sold by an industry that has open access to the resource of the antibiotic class's susceptibility (treatment effectiveness). Antibiotics are characterized by different expected recovery rates and production costs, which in conjunction with the class's treatment susceptibility determines their relative effectiveness. Our analysis reveals that the high‐quality antibiotic drug loses its comparative advantage over time making the low‐quality drug the treatment of last resort in the market equilibrium and the social optimum when antibiotic susceptibility cannot replenish. However, when antibiotic susceptibility is renewable, both antibiotics may be used in the long run, and the comparative advantage of the high‐quality drug may be restored in the social optimum that allows lowering infection in the long run. We develop the optimal tax/subsidy scheme that would induce antibiotic producers under open access to behave optimally and account for the social cost of infection and value of antibiotic susceptibility. We show that the welfare loss associated with the uncorrected open‐access allocation is highest; when the resource of antibiotic susceptibility is non‐renewable, high morbidity costs are incurred by individuals, and low social discount rates apply. Copyright © 2016 John Wiley & Sons, Ltd.
Estimation and Solution of Models with Expectations and Structural Changes
Authors: Kulish Mariano , Pagan Adrian 
Published: May 2016

SummaryIn this paper, we develop solutions for linearized models with forward‐looking expectations and structural changes under a variety of assumptions regarding agents' beliefs about those structural changes. For each solution, we show how its associated likelihood function can be constructed by using a ‘backward–forward’ algorithm. We illustrate the techniques with two examples. The first considers an inflationary program in which beliefs about the inflation target evolve differently from the inflation target itself, and the second applies the techniques to estimate a new Keynesian model through the Volcker disinflation. We compare our methodology with the alternative in which structural change is captured by switching between regimes via a Markov switching process. We show that our method can produce accurate results much faster than the Markov switching method as well as being easily adapted to handle beliefs departing from reality. Copyright © 2016 John Wiley & Sons, Ltd.
The Metabolism of Clopidogrel: CYP2C19 Is a Minor Pathway
Authors: Ford Neville F. 
Published: May 2016

AbstractThe major metabolic pathway of clopidogrel is conversion to carboxylic acid by an esterase (CES1), forming clopidogrelic acid (SR26334) that is inactive. There is agreement on the structure of the active metabolite; however, there are differing views about the mechanism of its formation. Sanofi studied the conversion of clopidogrel to the active metabolite using human liver microsomes. It was concluded that 2‐oxo‐clopidogrel was formed via CYP3A oxidation. From a subsequent in vitro study by Sankyo of the metabolism of clopidogrel using recombinant DNA CYPs, it was concluded that CYP2C19 was the major oxidative pathway. Such CYPs can give false‐negative results particularly with drugs such as clopidogrel that have high first‐pass metabolism in the enterocyte. CYP3A is present in the enterocyte but not CYP2C19. However, the view that clopidogrel is a CYP2C19 substrate was reinforced by a finding that omeprazole, a CYP2C19 inhibitor, reduced the ability of clopidogrel to inhibit platelet aggregation. The drug–drug interaction study of clopidogrel with omeprazole had the effect of reducing the area under the curve (AUC) of the clopidogrel active metabolite by 45%. However, a drug interaction study with a CYP3A inhibitor, grapefruit juice, caused a 6‐fold reduction in the AUC of the active metabolite. Clopidogrel is therefore now considered to be primarily a CYP3A4/5 substrate. CYP2C19 has a minor role whose effect can be detected using a sensitive methodology such as platelet aggregometry.
Expression for the Number of Spanning Trees of Line Graphs of Arbitrary Connected Graphs
Authors: Dong Fengming , Yan Weigen 
Published: May 2016

AbstractFor any graph G, let be the number of spanning trees of G, be the line graph of G, and for any nonnegative integer r, be the graph obtained from G by replacing each edge e by a path of length connecting the two ends of e. In this article, we obtain an expression for in terms of spanning trees of G by a combinatorial approach. This result generalizes some known results on the relation between and and gives an explicit expression if G is of order and size in which s vertices are of degree 1 and the others are of degree k. Thus we prove a conjecture on for such a graph G.
Observed short‐ and long‐term changes in summer precipitation over South Korea and their links to large‐scale circulation anomalies
Authors: Baek Hee‐Jeong , Kim Maeng‐Ki , Kwon Won‐Tae 
Published: May 2016

ABSTRACTWe investigated short‐ and long‐term changes in total and extreme summer precipitation and the characteristic patterns of atmospheric circulation and sea surface temperature (SST) anomalies related to wet summers over South Korea. Over the last century (1913–2012), the total and extreme summer precipitation showed a significant increase of 2.62 and 4.45% decade−1, respectively. Because extreme summer precipitation increased more rapidly than total summer precipitation, the contribution of extreme precipitation to total precipitation increased significantly by 2.48% decade−1. A two‐peak rainy season was substantially intensified, with a slight shift and a large increase of precipitation during the monsoon break period, indicating a shortening of the monsoon break period. The 20‐year return values of daily maximum precipitation increased at all stations except Mokpo, showing changes in the frequency of extreme events. During the last 40 years (1973–2012), the pattern of change in the precipitation indices was spatially heterogeneous, with a particularly significant increasing trend in extreme summer precipitation over the North‐central portion of western South Korea. When compared with long‐term trends over 1912–2012, recent short‐term trends showed more rapid increases in all precipitation indices, with the exception of the number of consecutive dry days. In addition, the number of consecutive wet days (CWD) increased significantly during the last 40 years, whereas the long‐term trend over the last century for CWD was not significant. These regional trends were confirmed by field significance at the 90% confidence level. From the composite analysis results, the positive anomalous North Pacific subtropical high, intensification of the upper‐level westerly Jet over Korea and its vertical coupling with the anomalous strong low‐level westerlies, and anomalous warm SST values in the western North Pacific region were linked to recent increases in extreme summer precipitation.
FRET Imaging of Enzyme‐Responsive HPMA Copolymer Conjugate
Authors: Zhang Rui , Yang Jiyuan , Radford D. Christopher , Fang Yixin , Kopeček Jindřich 
Published: May 2016

Fluorescence resonance energy transfer (FRET) is applied to investigate the enzyme‐responsive payload release from a macromolecular therapeutic. The donor Cy5 is attached to the N‐(2‐hydroxypropyl)methacrylamide (HPMA) copolymer backbone and the acceptor Cy7 is bound to the termini of enzyme‐sensitive peptide side chains. Upon exposure to an enzyme, the bond between the peptide and Cy7 is cleaved, thereby leading to the loss of FRET signal. This enzyme response is visualized at the cell, tissue and whole‐body levels. The in vitro results demonstrate that high expression of cathepsin B in tumor cells induces effective release of the drug model from conjugates resulting in a high concentration of payload inside tumor cells. The in vivo and ex vivo images show that the conjugate releases drug model faster in the ovarian tumor than in the normal tissues. The information will enhance the understanding of enzyme‐responsive polymer carriers and help to shape their design.image
Central Line Associated Blood Stream Infections in Pediatric Hematology/Oncology Patients With Different Types of Central Lines
Authors: Hord Jeffrey D. , Lawlor John , Werner Eric , Billett Amy L. , Bundy David G. , Winkle Cindi , Gaur Aditya H. ,   Children's Hospital Association Childhood Cancer and Blood Disorders Network
Published: May 2016

BackgroundCentral line associated bloodstream infections (CLABSIs) are a significant cause of morbidity and mortality in pediatric hematology/oncology (PHO) patients. Understanding the differences in CLABSI rates by central line (CL) type is important to inform clinical decisions.ProcedureCLABSI, using similar definitions, noted with three commonly used CL types (totally implanted catheter [port], tunneled externalized catheter [TEC], peripherally inserted central catheter [PICC]) and CL‐specific line days were prospectively tracked across 15 US PHO centers from May 2012 until April 2015 and CLABSI rates (CLABSI per 1,000 CL‐specific line days) were calculated. Host and organism characterstics associated with the CLABSI events were analyzed.ResultsOver the course of 2.8 million line days, 1,113 CLABSI events (397 in inpatients and 716 in ambulatory patients) were noted. The inpatient CLABSI rate was higher than the ambulatory CLABSI rate for each of the CL types: 1.48 versus 0.16 for ports, 3.51 versus 1.38 for TECs, and 3.07 versus 1.16 for PICCs, respectively. TECs and PICCs were associated with higher CLABSI rates than ports, inpatient and ambulatory.ConclusionsWe found that CLABSI rates were significantly higher for inpatients compared to ambulatory PHO patients for all CL types. Among ambulatory patients, TECs had the highest CLABSI rate and ports the lowest. Among inpatients, TECs and PICCs had higher CLABSI rates than ports but were not statistically different from one another. Cognizant that host and underlying disease attributes may contribute to these differences, these results can still inform CL choice in clinical practice.