bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Interaction of Isopenicillin N Synthase with Homologated Substrate Analogues δ‐(L‐α‐Aminoadipoyl)‐L‐homocysteinyl‐D‐Xaa Characterised by Protein Crystallography
Authors: Daruzzaman Adam , Clifton Ian J. , Adlington Robert M. , Baldwin Jack E. , Rutledge Peter J. 
Published: March 2013

AbstractIsopenicillin N synthase (IPNS) converts the linear tripeptide δ‐(L‐α‐aminoadipoyl)‐L‐cysteinyl‐D‐valine (ACV) into bicyclic isopenicillin N (IPN) in the central step in the biosynthesis of penicillin and cephalosporin antibiotics. Solution‐phase incubation experiments have shown that IPNS turns over analogues with a diverse range of side chains in the third (valinyl) position of the substrate, but copes less well with changes in the second (cysteinyl) residue. IPNS thus converts the homologated tripeptides δ‐(L‐α‐aminoadipoyl)‐L‐homocysteinyl‐D‐valine (AhCV) and δ‐(L‐α‐aminoadipoyl)‐L‐homocysteinyl‐D‐allylglycine (AhCaG) into monocyclic hydroxy‐lactam products; this suggests that the additional methylene unit in these substrates induces conformational changes that preclude second ring closure after initial lactam formation. To investigate this and solution‐phase results with other tripeptides δ‐(L‐α‐aminoadipoyl)‐L‐homocysteinyl‐D‐Xaa, we have crystallised AhCV and δ‐(L‐α‐aminoadipoyl)‐L‐homocysteinyl‐D‐S‐methylcysteine (AhCmC) with IPNS and solved crystal structures for the resulting complexes. The IPNS:FeII:AhCV complex shows diffuse electron density for several regions of the substrate, revealing considerable conformational freedom within the active site. The substrate is more clearly resolved in the IPNS:FeII:AhCmC complex, by virtue of thioether coordination to iron. AhCmC occupies two distinct conformations, both distorted relative to the natural substrate ACV, in order to accommodate the extra methylene group in the second residue. Attempts to turn these substrates over within crystalline IPNS using hyperbaric oxygenation give rise to product mixtures.
ChemInform Abstract: Synchrotron X‐Ray Powder Diffraction and Electronic Band Structure of α‐ and β‐Cu2ZnSiS4.
Authors: Rosmus Kimberly A. , Brunetta Carl D. , Srnec Matthew N. , Karuppannan Balamurugan , Aitken Jennifer A. 
Published: March 2013

AbstractCu2ZnSiS4 is synthesized by solid state reaction of the elements (graphite crucible, 1000 °C, 96 h).
ChemInform Abstract: Structure of Turbostratically Disordered Misfit Layer Compounds [(PbSe)0.99]1[WSe2]1, [(PbSe)1.00]1[MoSe2]1, and [(SnSe)1.03]1[MoSe2]1.
Authors: Smeller Mary M. , Heideman Colby L. , Lin Qiyin , Beekman Matt , Anderson Michael D. , Zschack Paul , Anderson Ian M. , Johnson David C. 
Published: March 2013

AbstractThe title compounds are prepared as thin films using the modulated elemental reactant method and their structures are characterized by synchrotron powder XRD and TEM.
ChemInform Abstract: Ternary Metastable Nitrides ε‐Fe2MN (M: Co, Ni): High‐Pressure, High‐Temperature Synthesis, Crystal Structure, Thermal Stability, and Magnetic Properties.
Authors: Guo Kai , Rau Dieter , Toffoletti Lorenzo , Mueller Carola , Burkhardt Ulrich , Schnelle Walter , Niewa Rainer , Schwarz Ulrich 
Published: March 2013

AbstractThe title compounds are prepared by high‐pressure reaction of ζ‐Fe2N (obtained from Fe and flowing NH3 at 708 K) and Ni or Co powder (15 GPa, 1473 K, 30 min).
ChemInform Abstract: Asymmetric Cyanation of α‐Ketiminophosphonates Catalyzed by Cinchona Alkaloids: Enantioselective Synthesis of Tetrasubstituted α‐Aminophosphonic Acid Derivatives from Trisubstituted α‐Aminophosphonates.
Authors: Vicario Javier , Ezpeleta Jose Maria , Palacios Francisco 
Published: March 2013

AbstractPyruvonitrile (II) is used as a cyanid source for the asymmetric cyanation of compounds (I).
ChemInform Abstract: Palladium‐Catalyzed C—H Functionalization Using Guanidine as a Directing Group: ortho‐Arylation and Olefination of Arylguanidines.
Authors: Shao Jiaan , Chen Wenteng , Giulianotti Marc A. , Houghten Richard A. , Yu Yongping 
Published: March 2013

AbstractIn the presence of Pd(O‐Ac)2 and K2S2O8, arylguanidines can be ortho‐arylated with electron‐neutral and electron‐rich arenes.
ChemInform Abstract: Permuting Diels—Alder and Robinson Annulation Stereopatterns.
Authors: Peng Feng , Dai Mingji , Angeles Angie R. , Danishefsky Samuel J. 
Published: March 2013

AbstractOctalones (V) are obtained by a Diels—Alder reaction of cyclohexenone (I) with dienes (II) followed by a silica‐mediated isomerization of octalones (III) and a subsequent Saegusa oxidation of silylenol (IV).
ChemInform Abstract: N‐Heterocyclic Carbene Dichotomy in Pd‐Catalyzed Acylation of Aryl Chlorides via C—H Bond Functionalization.
Authors: Flores‐Gaspar Areli , Gutierrez‐Bonet Alvaro , Martin Ruben 
Published: March 2013

AbstractUnder conditions A), ether aromatic chlorides of type (I), (VII), and (IX) undergo new, site‐selective intramolecular cyclization to benzocyclobutenones.
ChemInform Abstract: Direct Synthesis of 2,3‐Diaryloxirane‐2,3‐dicarbonitriles from Aroyl Chlorides Using Potassium Hexacyanoferrate(II) as an Eco‐Friendly Cyanide Source.
Authors: Li Zheng , Xu Jun , Niu Pengxian , Liu Chenhui , Yang Jingya 
Published: March 2013

AbstractThe important synthetic intermediates can be prepared within a relatively short time.
ChemInform Abstract: Highly Enantio‐ and Diastereoselective Reactions of γ‐Substituted Butenolides Through Direct Vinylogous Conjugate Additions.
Authors: Zhang Wen , Tan Davin , Lee Richmond , Tong Guanghu , Chen Wenchao , Qi Baojian , Huang Kuo‐Wei , Tan Choon‐Hong , Jiang Zhiyong 
Published: March 2013

AbstractAddition of γ‐substituted butenolides to oxazolidinone enoates in the presence of the chiral urea ATU affords γ,γ‐disubstituted butenolides with excellent enantioselectivity, generally as single diastereomers.
ChemInform Abstract: Synthesis of Fluorinated Tricyclic Scaffolds by Intramolecular [2 + 2] Photocycloaddition Reactions.
Authors: Fort Diego A. , Woltering Thomas J. , Nettekoven Matthias , Knust Henner , Bach Thorsten 
Published: March 2013

AbstractThe title reaction using fluorinated alkene substrates allows the access to various tricyclic systems.
ChemInform Abstract: One‐Pot Synthesis of Chiral Dihydrobenzofuran Framework via Rh/Pd Catalysis.
Authors: Tsui Gavin Chit , Tsoung Jennifer , Dougan Patrick , Lautens Mark 
Published: March 2013

AbstractCoupling of the oxabicycle (I) with boronic ester (II) under the catalytic conditions shown followed by ring closure allows a highly enantioselective access to the dihydrobenzofuran (III).
ChemInform Abstract: Direct Catalytic Enantioselective Vinylogous Aldol Reaction of α‐Branched Enals with Isatins.
Authors: Cassani Carlo , Melchiorre Paolo 
Published: March 2013

AbstractProlinol‐catalyzed reaction of isatins with α‐alkylated enals provides a facile, regio‐, and highly enantioselective approach to 3‐hydroxyoxindoles of type (III) and (V).
ChemInform Abstract: 3‐Alkenylation or 3‐Alkylation of Indole with Propargylic Alcohols: Construction of 3,4‐Dihydrocyclopenta[b]indole and 1,4‐Dihydrocyclopenta[b]indole in the Presence of Different Catalysts.
Authors: Zhang Li , Zhu Yuanxun , Yin Guangwei , Lu Ping , Wang Yanguang 
Published: March 2013

AbstractTfOH‐mediated coupling of 2‐unsubstituted N‐methylindoles with propargylic alcohols results in formation of 3‐alkenylated indoles which spontaneously undergo cyclization to afford 3,4‐dihydrocyclopentaindoles.
ChemInform Abstract: DABCO and Bu3P Catalyzed [4 + 2] and [3 + 2] Cycloadditions of 3‐Acyl‐2H‐chromen‐ones and Ethyl 2,3‐Butadienoate.
Authors: Wang Ying , Yu Zhi‐Hua , Zheng Hu‐Fei , Shi De‐Qing 
Published: March 2013

AbstractDABCO‐catalyzed [4 + 2] cycloaddition reaction leads to dihydropyran‐fused chromen‐2‐ones (III) detectable only as the E‐isomer.
ChemInform Abstract: Iridium‐Catalyzed Asymmetric Hydrogenation of Pyridinium Salts.
Authors: Ye Zhi‐Shi , Chen Mu‐Wang , Chen Qing‐An , Shi Lei , Duan Ying , Zhou Yong‐Gui 
Published: March 2013

AbstractKey feature in the preparation of chiral piperidines is the activation of simple pyridines as N‐benzyl‐pyridinium bromides.
ChemInform Abstract: Rh‐Catalyzed Addition of Arylboroxines to Cyclic N‐(Isopropanesulfinyl)ketimines.
Authors: Jung Hyung Hoon , Buesking Andrew W. , Ellman Jonathan A. 
Published: March 2013

AbstractA wide range of cyclic amine products is available and the sulfinyl group can be smoothly removed.
ChemInform Abstract: Intramolecular Direct C—H Bond Arylation from Aryl Chlorides: A Transition‐Metal‐Free Approach for Facile Access of Phenanthridines.
Authors: Wu Yinuo , Wong Shun Man , Mao Fei , Chan Tek Long , Kwong Fuk Yee 
Published: March 2013

AbstractUsing this method, a wide range of biologically important phenanthridines and related compounds is available.
ChemInform Abstract: Unexpected C—C Bond Cleavage: A Route to 3,6‐Diarylpyridazines and 6‐Arylpyridazin‐3‐ones from 1,3‐Dicarbonyl Compounds and Methyl Ketones.
Authors: Gao Qinghe , Zhu Yanping , Lian Mi , Liu Meicai , Yuan Jingjing , Yin Guodong , Wu Anxin 
Published: March 2013

AbstractA new, mild, and efficient method to prepare 3,6‐disubstituted pyridazines and 6‐arylpyridazinones is reported.
ChemInform Abstract: Yb(NTf2)3‐Catalyzed [3 + 3] Cycloaddition Between Isatin Ketonitrones and Cyclopropanes to Construct Novel Spiro[tetrahydro‐1,2‐oxazine]oxindoles.
Authors: Yang Hai‐Bin , Shi Min 
Published: March 2013

AbstractThe first example of the intramolecular [3 + 3] cycloaddition of ketone‐derived nitrones (I) and cyclopropanes (II) is described.
ChemInform Abstract: Pinacolborane as the Boron Source in Nitrogen‐Directed Borylations of Aromatic N,N‐Dimethylhydrazones.
Authors: Lopez‐Rodriguez Rocio , Ros Abel , Fernandez Rosario , Lassaletta Jose M. 
Published: March 2013

AbstractIr2(cod)2(OMe)2 and HYD efficiently promote the ortho‐selective borylation of hydrazones with readily available pinacolborane.
ChemInform Abstract: Catalytic C—Se Bond Formation under very Mild Conditions for the Two‐Step, One‐Pot Synthesis of Aryl Selenoacetates.
Authors: Grenader Konstantin , Schuepbach Bjoern , Peters Annabell , Kuemmel Oliver , Halter Oliver , Terfort Andreas 
Published: March 2013

AbstractThe reaction uses a palladium catalyst and proceeds under mild conditions.
ChemInform Abstract: Diastereoselective Metal‐Catalyzed Synthesis of C‐Aryl and C‐Vinyl Glycosides.
Authors: Nicolas Lionel , Angibaud Patrick , Stansfield Ian , Bonnet Pascal , Meerpoel Lieven , Reymond Sebastien , Cossy Janine 
Published: March 2013

AbstractCobalt‐catalyzed cross‐coupling of aryl and vinyl Grignard reagents with mannose (I) and galactose (X) is highly diastereoselective to give only the α‐products.
ChemInform Abstract: Sugar‐Functionalized Carbon Nanotubes: Unique Properties and Interactions with Biological Species
Authors: Anilkumar Parambath , Tackett, Kenneth N. II , Lu Fushen , Luo Pengju G. , Gu Lingrong , Anderson Ankoma , Sun Ya‐Ping 
Published: March 2013

AbstractReview: 49 refs.
Production of Liquid Hydrocarbons with CO2 as Carbon Source based on Reverse Water‐Gas Shift and Fischer‐Tropsch Synthesis
Authors: Kaiser Philipp , Unde Rajabhau Bajirao , Kern Christoph , Jess Andreas 
Published: March 2013

AbstractThe substitution of fossil fuels by renewable energy sources is needed to decrease greenhouse gas emissions, especially CO2. Wind and solar power are today considered as attractive alternatives for electric power generation, but are not suitable for providing base load. Thus, efficient storage of electrical energy is inevitable. Liquid hydrocarbons (HCs) exhibit an excellent volumetric energy density and offer various opportunities for storing electric energy. They can be produced by CO2 and renewable H2 (generated by water electrolysis) in a two step process. The first step is generation of syngas by reverse water‐gas shift (RWGS) at elevated temperatures; the second step comprises the production of liquid hydrocarbons by Fischer‐Tropsch (FT) synthesis. The experiments on RWGS with a commercial Ni‐catalyst show that a CO2 conversion of around 80 % can be reached at 800 °C within a very short residence time of less than < 0.1 s. The experiments on FTS with Fe as catalyst and syngas containing different amounts of CO2 indicate that the influence of CO2 on CO conversion and product selectivities (including net CO2 production by water‐gas shift) is insignificant if the inlet partial pressures of H2 and CO are kept constant. If CO is substituted by CO2, less HCs are formed, the water‐gas shift is repressed, and methane selectivity increases.
Photocatalytic CO2 Reduction using Non‐Titanium Metal Oxides and Sulfides
Authors: Navalón Sergio , Dhakshinamoorthy Amarajothi , Álvaro Mercedes , Garcia Hermenegildo 
Published: March 2013

AbstractTitanium dioxide (TiO2) is by far the most widely used photocatalyst both for the degradation of pollutants and in the field of renewable energies for the production of solar fuels. However, TiO2 has strong limitations in CO2 reduction, particularly under visible light irradiation. The flat‐band potential of electrons in the conduction band of TiO2 is lower than that required for CO2 reduction and, therefore, it seems appropriate to develop and validate materials other than TiO2. In addition, the photoresponse of TiO2 requires photons of wavelengths in the UV range shorter than 380 nm and strategies to implement a visible‐light photoresponse on TiO2 by doping have not been completely satisfactory particularly because of problems in reproducibility and stability of the materials. For these reasons, we focus in this Review on semiconductors other than TiO2 that show photocatalytic activity in CO2 reduction. Attention has been paid to the irradiation conditions to put the productivity data into context. The role of co‐catalyst and heterojunctions to increase the efficiency of charge separation is also discussed. Our aim is to describe the state of the art in the field of photocatalytic CO2 reduction using materials other than TiO2, trying to trigger further research in this area.
Homoleptic Bis(aryl)acenaphthenequinonediimine–CuI Complexes – Synthesis and Characterization of a Family of Compounds with Improved Light‐Gathering Characteristics
Authors: Papanikolaou Panagiotis , Akrivos Pericles D. , Czapik Agnieszka , Wicher Barbara , Gdaniec Maria , Tkachenko Nikolai 
Published: March 2013

AbstractA group of bis(aryl)acenaphthenequinonediimine (Ar‐BIAN) ligands were synthesized through a modified procedure, which bypasses the need for absolutely dry conditions during the initial template synthesis. The molecular and electronic structure of the corresponding homoleptic [Cu(Ar‐BIAN)2]BF4 complexes were probed by means of a variety of spectroscopic methods. In accord with solution 13C NMR spectra, X‐ray crystallography reveals D2 or approximate D2 symmetry for the [Cu(p‐Cl‐BIAN)2]+ and [Cu(p‐Me‐BIAN)2]+ cations and noncrystallographic C2 symmetry for the [Cu(o‐Ph‐BIAN)2]+ cation. The structures of the p‐Cl‐, p‐Me, and o‐Ph‐BIAN complexes agree with the presence of ligands in their neutral form according to the lengths of the relevant C–C and C=N bonds of the organic skeleton. The concerted stereo–electronic effects of the substituents on the aryl rings affect the electron donor/acceptor capacities of the ligands and the structures of the complexes, as the study of the visible absorption spectra of the complexes indicates. The spectra of the complexes are dominated by intense and broad metal‐to‐ligand charge transfer (MLCT) bands that enter the near‐infrared (NIR) region. Additionally, electrochemical studies undertaken reveal several successive electron capture and release processes, which further manifest the redox versatility of the ligands.
N‐Heterocyclic Carbenes Functioning as Monoligating Clamps
Authors: Teci Matthieu , Brenner Eric , Matt Dominique , Toupet Loïc 
Published: March 2013

AbstractBenzimidazolium salts N,N′‐disubstituted with 9‐alkylfluorenyl groups (3a–e, alkyl = methyl, ethyl, propyl, butyl, benzyl) have been synthesised in high yields in three steps from o‐phenylenediamine. This amine was treated with fluorenone in the presence of TiCl4 and tetramethylethylenediamine (TMEDA) to form N,N′‐bis(9H‐fluoren‐9‐ylidene)benzene‐1,2‐diamine (1) in 91 % yield. Diamines 2a–e were then obtained in yields superior or equal to 77 % by reacting diimine 1 with the appropriate organolithium reagent. In the final step, diamines 2a–e were treated with ethylorthoformate under acidic conditions to afford benzimidazolium salts 3a–e. These were readily converted into the PEPPSI palladium complexes 4a–e (PEPPSI = pyridine‐enhanced precatalyst preparation stabilisation and initiation). NMR and X‐ray diffraction studies revealed that the flat fluorenylidene moiety orientates the alkyl groups towards the metal centre and because of its restricted rotational freedom makes the ligand bulkiness time independent. Thus, the metal centre is permanently confined between the two alkyl groups, and thereby forms a monoligating clamp with the carbenic centre. The CH2 groups close to the palladium ion give rise to anagostic C–H···Pd interactions. Catalytic tests revealed that the palladium complexes 4a–e are highly efficient in Suzuki–Miyaura cross‐coupling reactions; their activity is equal or superior to the best PEPPSI catalysts reported to date.
Simultaneous determination of diclofenac and its common counter‐ions in less than 1 minute using capillary electrophoresis with contactless conductivity detection
Authors: Cunha Rafael R. , Gimenes Denise T. , Munoz Rodrigo A. A. , do Lago Claudimir L. , Richter Eduardo M. 
Published: March 2013

This paper presents a method for fast and simultaneous determination of diclofenac (DCF) and its common counter‐ions (potassium, sodium, and diethylammonium) using CE with capacitively coupled contactless conductivity detection (CE‐C4D). On the basis of a single electropherogram (about 50 s), the proposed method allows the determination of the stoichiometry, absolute quantification and evaluation of the degradation degree of the active pharmaceutical ingredient (DCF). A linear working range from 100 to 500 μmol/L was obtained for all analytes in an equimolar TRIS/TAPS (10 mmol/L) solution as the background electrolyte as well as adequate LOD (7, 6, 7, and 10 μmol/L for K+, Na+, diethylammonium, and DCF, respectively). The proposed method was applied to the analysis of pharmaceutical formulations (tablets and spray form) with similar results to those achieved by HPLC (DCF) or flame photometry (K and Na) at a 95% confidence level.
Transforming Silo‐Steering Into a Performance Governance System: The Case of the Finnish Central Government
Authors: Uusikylä Petri 
Published: March 2013

AbstractThis chapter discusses efforts by the Finnish central government to reform its approach to governing and service delivery through the implementation of performance management in various forms. In this context, the implementation and utilization of performance evaluation has been fragmented and narrow, resulting in limited use of evaluative data in policy development and service improvement. The author argues that the performance‐governance model offers a framework for approaching performance management through the lens of the democratic government and even to support the use of theory‐of‐change strategies to assess government's contribution to desirable societal changes. © Wiley Periodicals, Inc., and the American Evaluation Association.
Rethinking the Relationship Among Monitoring, Evaluation, and Results‐Based Management: Observations From Canada
Authors: Lahey Robert , Nielsen Steffen Bohni 
Published: March 2013

AbstractThis chapter outlines the development of performance monitoring and program evaluation at the federal level of the government of Canada. This approach stands out, as it has had a dual emphasis on both monitoring and evaluation as complementary forms of knowledge production. However, throughout its history emphases on management and accountability have shifted. The authors argue that to fulfill its potential to support results‐based management the Canadian government must adopt a more stable, balanced, and strategic approach to both performance monitoring and program evaluation. © Wiley Periodicals, Inc., and the American Evaluation Association.
Managing for Results in the U.S. Not‐for‐Profit Sector: Applying Complementary Approaches of Knowledge Production at the Center for Employment Opportunities
Authors: Dudding Brad , Nielsen Steffen Bohni 
Published: March 2013

AbstractThis chapter investigates the case of the Center for Employment Opportunities (CEO), a not‐for‐profit organization dedicated to providing immediate and comprehensive employment services to persons with criminal convictions. CEO prepares returning prisoners for the workforce with strong employment‐retention outcomes and proven impacts (in a randomized control trial by MDRC) showing significant reduction in recidivism. In this chapter the authors survey how CEO manages its performance through the use of both performance measurement and monitoring and evaluation. Also, the authors argue that performance measurement and evaluation must be seen as complementary forms of knowledge production and that both need to be integral to performance management. © Wiley Periodicals, Inc., and the American Evaluation Association.
Novel tandem germline RET proto‐oncogene mutations in a patient with multiple endocrine neoplasia type 2B: Report of a case and a literature review of tandem RET mutations with in silico analysis
Authors: Nakao Kanako–Tanase , Usui Takeshi , Ikeda Mayumi , Mori Yusuke , Yamamoto Tetsuro , Kawashima Sachiko–Tsukamoto , Nanba Kazutaka , Yuno Akiko , Tamanaha Tamiko , Tagami Tetsuya , Naruse Mitsuhide , Asato Ryo , Shimatsu Akira 
Published: March 2013

BackgroundMultiple endocrine neoplasia type 2B (MEN2B) is the rarest and most aggressive form of MEN2. MEN2B cases usually carry either an M918T or A883T mutation of the RET, but to date, there are 3 atypical MEN2B caused by tandem mutations.Methods and ResultsA 32‐year‐old woman with no family history of medullary thyroid carcinoma (MTC) presented with a neck tumor and multiple mucosal nodules. She was diagnosed with MEN2B. Genetic analyses of RET revealed that she had 2 mutations, Q781R and V804M. Subclone and genetic analyses revealed that Q781R was on the paternal allele and V804M was a de novo. In silico analysis of the tandem mutations showed a high prediction score.ConclusionsWe describe a novel combination of tandem RET mutations (Q781R/V804M) in a MEN2B‐like patient. In silico analysis showed a high prediction score, which was compatible with the clinical phenotype in the present case. © 2012 Wiley Periodicals, Inc. Head Neck 35: E363–E368, 2013