bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions and Encapsulation of Vitamins C, B3, and B6 with Dendrimers in Water
Authors: Boisselier Elodie , Liang Liyuan , Dalko‐Csiba Maria , Ruiz Jaime , Astruc Didier 
Published: April 2010

AbstractTitrations of commercial diaminobutane (DAB) and polyamidoamine (PAMAM) dendrimers by vitamins C (ascorbic acid, AA), B3 (nicotinic acid), and B6 (pyridoxine) were monitored by 1H NMR spectroscopy using the chemical shifts of both dendrimer and vitamin protons and analyzed by comparison with the titration of propylamine. Quaternarizations of the terminal primary amino groups and intradendritic tertiary amino groups, which are nearly quantitative with vitamin C, were characterized by more or less sharp variations (Δδ) of the 1H chemical shift (δ) at the equivalence points. The peripheral primary amino groups of the DAB dendrimers were quaternarized first, but not selectively, whereas a sharp chemical‐shift variation was recorded for the inner methylene protons near the tertiary amines, thereby indicating encapsulation, when all the dendritic amines were quaternarized. With DAB‐G5‐64‐NH2, some excess acid is required to protonate the inner amino groups, presumably because of basicity decrease due to excess charge repulsion. On the other hand, this selectivity was not observed with PAMAM dendrimers. The special case of the titration of the dendrimers by vitamin B6 indicates only dominant supramolecular hydrogen‐bonding interactions and no quaternarization, with core amino groups being privileged, which indicates the strong tendency to encapsulate vitamins. With vitamin B3, a carboxylic acid, titration of DAB‐G3‐16‐NH2 shows that only six peripheral amino groups are protonated on average, even with excess vitamin B3, because protonation is all the more difficult due to increased charge repulsion, as positive charges accumulate around the dendrimer. Inner amino groups interact with this vitamin, however, thus indicating encapsulation presumably with supramolecular hydrogen bonding without much charge transfer.
Controlling Stereoselectivity in the Aminocatalytic Enantioselective Mannich Reaction of Aldehydes with In Situ Generated N‐Carbamoyl Imines
Authors: Galzerano Patrizia , Agostino Dario , Bencivenni Giorgio , Sambri Letizia , Bartoli Giuseppe , Melchiorre Paolo 
Published: April 2010

AbstractA simple and convenient method for the direct, aminocatalytic, and highly enantioselective Mannich reactions of aldehydes with in situ generated N‐carbamoyl imines has been developed. Both α‐imino esters and aromatic imines serve as suitable electrophilic components. Moreover, the judicious selection of commercially available secondary amine catalysts allows selective access to the desired stereoisomer of the N‐tert‐butoxycarbonyl (Boc) or N‐carbobenzyloxy (Cbz) Mannich adducts, with high control over the syn or anti relative configuration and almost perfect enantioselectivity. Besides the possibility to fully control the stereochemistry of the Mannich reaction, the main advantage of this method lies in the operational simplicity; the highly reactive N‐carbamate‐protected imines are generated in situ from stable and easily handled α‐amido sulfones.
Assembly of π‐Conjugated Phosphole Azahelicene Derivatives into Chiral Coordination Complexes: An Experimental and Theoretical Study
Authors: Graule Sebastien , Rudolph Mark , Shen Wenting , Williams J. A. Gareth , Lescop Christophe , Autschbach Jochen , Crassous Jeanne , Réau Régis 
Published: April 2010

AbstractAza[n]helicene phosphole derivatives have been prepared from aza[n]helicene diynes by the Fagan–Nugent route. Their photophysical properties (UV/Vis absorption and emission behavior) have been evaluated. Their behavior as P,N chelates towards coordination to PdII and CuI has been investigated: metal–bis(aza[n]helicene phosphole) assemblies are formed by a highly stereoselective coordination process, as demonstrated by X‐ray crystallography. An aza[6]helicene phosphole bearing an enantiopure helicene part has been obtained, which allows the preparation of enantiopure PdII and CuI complexes with original topologies and high molar rotation (MR) and circular dichroism (CD). The structure–property relationship established from the experimental data has been studied in detail by theoretical studies (TDDFT calculations of UV/Vis, CD, and MR). Aza[n]helicene phosphole derivatives show π conjugation extended over the entire molecule, and its influence on the MR of aza[6]helicene phosphole 5 c has been demonstrated. Finally, it has been shown that the nature of the metal (coordination geometry and electronic interaction) can have a great impact on the amplitude of the chiroptical properties in metal–bis(aza[n]helicene phosphole) assemblies.
Hierarchical ZSM‐5 Zeolites in Shape‐Selective Xylene Isomerization: Role of Mesoporosity and Acid Site Speciation
Authors: Fernandez Christian , Stan Irina , Gilson Jean‐Pierre , Thomas Karine , Vicente Aurélie , Bonilla Adriana , Pérez‐Ramírez Javier 
Published: April 2010

AbstractThe isomerization of o‐xylene, a prototypical example of shape‐selective catalysis by zeolites, was investigated on hierarchical porous ZSM‐5. Extensive intracrystalline mesoporosity in ZSM‐5 was introduced by controlled silicon leaching with NaOH. In addition to the development of secondary porosity, the treatment also induced substantial aluminum redistribution, increasing the density of Lewis acid sites located at the external surface of the crystals. However, the strength of the remaining Brønsted sites was not changed. The mesoporous zeolite displayed a higher o‐xylene conversion than its parent, owing to the reduced diffusion limitations. However, the selectivity to p‐xylene decreased, and fast deactivation due to coking occurred. This is mainly due to the deleterious effect of acidity at the substantially increased external surface and near the pore mouths. A consecutive mild HCl washing of the hierarchical zeolite proved effective to increase the p‐xylene selectivity and reduce the deactivation rate. The HCl‐washed hierarchical ZSM‐5 displayed an approximately twofold increase in p‐xylene yield compared to the purely microporous zeolite. The reaction was followed by operando infrared spectroscopy to simultaneously monitor the catalytic performance and the buildup of carbonaceous deposits on the surface. Our results show that the interplay between activity, selectivity, and stability in modified zeolites can be optimized by relatively simple post‐synthesis treatments, such as base leaching (introduction of mesoporosity) and acid washing (surface acidity modification).
Template‐Assembled Synthetic G‐Quadruplex (TASQ): A Useful System for Investigating the Interactions of Ligands with Constrained Quadruplex Topologies
Authors: Murat Pierre , Bonnet Romaric , Van der Heyden Angéline , Spinelli Nicolas , Labbé Pierre , Monchaud David , Teulade‐Fichou Marie‐Paule , Dumy Pascal , Defrancq Eric 
Published: April 2010

AbstractA new biomolecular device for investigating the interactions of ligands with constrained DNA quadruplex topologies, using surface plasmon resonance (SPR), is reported. Biomolecular systems containing an intermolecular‐like G‐quadruplex motif 1 (parallel G‐quadruplex conformation), an intramolecular G‐quadruplex 2, and a duplex DNA 3 have been designed and developed. The method is based on the concept of template‐assembled synthetic G‐quadruplex (TASQ), whereby quadruplex DNA structures are assembled on a template that allows precise control of the parallel G‐quadruplex conformation. Various known G‐quadruplex ligands have been used to investigate the affinities of ligands for intermolecular 1 and intramolecular 2 DNA quadruplexes. As anticipated, ligands displaying a π‐stacking binding mode showed a higher binding affinity for intermolecular‐like G‐quadruplexes 1, whereas ligands with other binding modes (groove and/or loop binding) showed no significant difference in their binding affinities for the two quadruplexes 1 or 2. In addition, the present method has also provided information about the selectivity of ligands for G‐quadruplex DNA over the duplex DNA. A numerical parameter, termed the G‐quadruplex binding mode index (G4‐BMI), has been introduced to express the difference in the affinities of ligands for intermolecular G‐quadruplex 1 against intramolecular G‐quadruplex 2. The G‐quadruplex binding mode index (G4‐BMI) of a ligand is defined as follows: G4‐BMI=KDintra/KDinter, where KDintra is the dissociation constant for intramolecular G‐quadruplex 2 and KDinter is the dissociation constant for intermolecular G‐quadruplex 1. In summary, the present work has demonstrated that the use of parallel‐constrained quadruplex topology provides more precise information about the binding modes of ligands.
Asymmetric Catalytic Hydrogenolysis of ArylHalide Bonds in Fused Arene Chromium and Ruthenium Complexes
Authors: Mercier Audrey , Urbaneja Xavier , Yeo Wee Chuan , Chaudhuri Piyali Datta , Cumming Graham R. , House David , Bernardinelli Gérald , Kündig E. Peter 
Published: April 2010

AbstractAccess to highly enantioenriched planar chiral [Cr(5‐bromonaphthalene)(CO)3] (6), [Ru(η5‐C5R5)(5‐bromonaphthalene)][PF6] (42) and [Ru(η5‐C5R5)(4‐bromoindene)] (44) was sought using asymmetric hydrogenolysis of [Cr(5,8‐dibromonaphthalene)(CO)3] (5), [Ru(η5‐C5R5)(5,8‐dibromonaphthalene)] (39) and [Ru(η5‐C5R5)(4,7‐dibromoindene)] (40), respectively. Initial efforts focused on the chromium complex 5. Pd0 catalysts with dimethoxyethane as the solvent and LiBH4 or NaBH3CN as a hydride source worked best. Nineteen chiral bidentate phosphorus ligands were screened in this reaction. Asymmetric induction was low to modest with product ee’s in the range of 4 to 52 % and yields of 6 of up to 70 %. Chiral phosphoramidite ligands proved superior and a bulky ligand derived from a Whitesell amine and 3,3′‐diphenyl‐binaphtol afforded 6 with an ee of 97 %. The high enantioselectivity is largely due to the initial desymmetrization reaction though kinetic resolution also plays an important role as shown by the determination of a selectivity factor s=8.5 at −10 °C. Initially high ligand loadings (4 equiv/Pd) were necessary to achieve good asymmetric induction. This could be traced to the trapping of the chiral ligand by borane formed in the reaction. Addition of 1,4‐diazabicyclo[2.2.2]octane (DABCO) suppressed this, and its addition led to the use of Pd and chiral ligand in a 1:1.2 ratio. Asymmetric hydrogenolysis of cationic dibromonaphthalene and neutral dibromoindenyl complexes of Ru cyclopentadienyl complexes was investigated and afforded the following results: [RuCp(5‐bromonaphthalene)][PF6] (39 a; 75 %, 90 % ee), [RuCp*(5‐bromonaphthalene)] [PF6] (39 b; 88 %, 99 % ee), [RuCp(4‐bromoindenyl)] (44 a; 72 %, 96 % ee), and [RuCp*(4‐bromoindenyl)] (44 b; 62 %, 68 % ee).
Selective Gas Adsorption in the Flexible Metal–Organic Frameworks Cu(BDTri)L (L=DMF, DEF)
Authors: Demessence Aude , Long Jeffrey R. 
Published: April 2010

AbstractUse of the ditopic ligand 1,4‐benzenedi(1H‐1,2,3‐triazole) (H2BDTri) enabled isolation of two new three‐dimensional metal–organic frameworks of formulae Cu(BDTri)L in which L=DMF (1) and diethylformamide (DEF; 2). These compounds have the same primary structure, featuring one‐dimensional channels with the bridging DMF or DEF molecules pointing into the cavity. Upon exposure to solvent vapors, both display a reversible flexibility, as characterized by single‐crystal to single‐crystal phase transitions in 1. The O2 adsorption isotherms for the compounds show a two‐step adsorption behavior associated with a permanent microporosity and a pore‐opening process. In the case of N2 adsorption, only 1 exhibits a two‐step adsorption isotherm, whereas 2 does not present any pore opening, demonstrating that design of a flexible framework cavity can control the pore opening and thereby possibly enhance O2/N2 separation.
Transition‐Metal‐Catalyzed Synthesis of Hydroxylated Arenes
Authors: Alonso Diego A. , Nájera Carmen , Pastor Isidro M. , Yus Miguel 
Published: April 2010

AbstractAn overview of the recent bibliography in the transition‐metal‐catalyzed hydroxylation of aryl derivatives is presented. Two reaction protocols are considered: 1) CH activation/hydroxylation and, 2) cross‐coupling hydroxylation of aryl halides. The achievements and limitations for both procedures are described taking into consideration different metal catalyst/oxidant combinations.
ChemInform Abstract: Synthesis, Structure, and Bonding in K12Au21Sn4. A Polar Intermetallic Compound with Dense Au20 and Open AuSn4 Layers.
Authors: Li Bin , Kim Sung‐Jin , Miller Gordon J. , Corbett John D. 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Combustion Synthesis and Luminescence Investigation of Na3Al2(PO4)3:RE (RE: Ce3+, Eu3+ and Mn2+) Phosphor.
Authors: Nagpure I. M. , Shinde K. N. , Kumar Vinay , Ntwaeaborwa O. M. , Dhoble S. J. , Swart H. C. 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Multiband Orange—Red Photoluminescence of Eu3+ Ions in New “114” LnBaZn3GaO7 and LnBaZn3AlO7 Oxides.
Authors: Saradhi M. P. , Raveau B. , Caignaert V. , Varadaraju U. V. 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Highly Uniform YBO3 Hierarchical Architectures: Facile Synthesis and Tunable Luminescence Properties.
Authors: Jia Guang , You Hongpeng , Liu Kai , Zheng Yuhua , Guo Ning , Jia Junjiao , Zhang Hongjie 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Luminescence Properties of Lanthanide and Transition Metal Ion‐Doped Ba2LaNbO6: Detection of MnO8‐6 and CrO9‐6 Clusters.
Authors: Tanner Peter A. , Pan Zaifa 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Isothermal Section of the Cu—Mn—Si Ternary System at 700 °C.
Authors: Liu Shuhong , Du Yong , Zhang Chao , Xu Honghui , Huang Baiyun , Liang Jianlie , Zhou Yichun , Zheng Feng , Li Yiwei 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Photolysis of Aqueous [(NH3)5Os(μ‐N2)Os (NH3)5]5+: Cleavage of Dinitrogen by an Intramolecular Photoredox Reaction.
Authors: Kunkely Horst , Vogler Arnd 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Direct Solid‐State Synthesis at High Pressure of New Mixed‐Metal Oxynitrides: LnZrO2N (Ln: Pr, Nd, and Sm).
Authors: Yang Minghui , Rodgers Jennifer A. , Middler Lawrence C. , Oro‐Sole Judith , Jorge A. Belen , Fuertes Amparo , Attfield J. Paul 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Studies on the New UFe2B6 Phase.
Authors: Dias M. , Carvalho P. A. , Sologub O. , Pereira L. C. J. , Santos I. C. , Goncalves A. P. 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Nitrate and Perchlorate Complexes of Uranium(IV).
Authors: Crawford Margaret‐Jane , Ellern Arkady , Karaghiosoff Konstantin , Mayer Peter 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: A New Ni12 Cluster Based on Polyoxometalate Ligands.
Authors: Zhang Hong‐Mei , Li Yang‐Guang , Lu Ying , Clerac Rodolphe , Zhang Zhi‐Ming , Wu Qiong , Feng Xiao‐Jia , Wang En‐Bo 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: AgIISO4: A Genuine Sulfate of Divalent Silver with Anomalously Strong One‐Dimensional Antiferromagnetic Interactions.
Authors: Malinowski Przemyslaw J. , Derzsi Mariana , Mazej Zoran , Jaglicic Zvonko , Gawel Bartlomiej , Lasocha Wieslaw , Grochala Wojciech 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Palladium‐Catalyzed [3C + 2C + 2C] Cycloaddition of Enynylidenecyclopropanes: Efficient Construction of Fused 5‐7‐5 Tricyclic Systems.
Authors: Bhargava Gaurav , Trillo Beatriz , Araya Marisel , Lopez Fernando , Castedo Luis , Mascarenas Jose L. 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Sigma‐1 Ligands: Tic‐Hydantoin as a Key Pharmacophore.
Authors: Toussaint Marion , Mousset Deborah , Foulon Catherine , Jacquemard Ulrich , Vaccher Claude , Melnyk Patricia 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Highly Active and Selective Semihydrogenation of Alkynes with the Palladium Nanoparticles‐Tetrabutylammonium Borohydride Catalyst System.
Authors: Hori Junichi , Murata Kunihiko , Sugai Toshiki , Shinohara Hisanori , Noyori Ryoji , Arai Noriyoshi , Kurono Nobuhito , Ohkuma Takeshi 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Expanded Scope for the Iridium‐Catalyzed Asymmetric Isomerization of Primary Allylic Alcohols Using Readily Accessible Second‐Generation Catalysts.
Authors: Mantilli Luca , Mazet Clement 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: N‐Arylation of Azaheterocycles with Aryl and Heteroaryl Halides Catalyzed by Iminodiacetic Acid Resin‐Chelated Copper Complex.
Authors: Wu Xiang Mei , Wang Yan 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: The First DMAP‐Mediated Palladium‐Free Tsuji—Trost‐Type Reaction of Cyclic and Acyclic Baylis—Hillman Alcohols with Active Methylene Compounds.
Authors: Mhasni Olfa , Rezgui Farhat 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Acid‐Mediated Activation of Modified Ring‐Closing Metathesis Catalysts.
Authors: Kim Seyoung , Hwang Wonmi , Lim In Seon , Kim Sung Hye , Lee Sang‐gi , Kim B. Moon 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Scandium‐Catalyzed Regio‐ and Stereospecific Methylalumination of Silyloxy/Alkoxy‐Substituted Alkynes and Alkenes.
Authors: Takimoto Masanori , Usami Saori , Hou Zhaomin 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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: Unexpected Products from the Attempted Organolithium‐Mediated Conversion of β‐Methoxy Aziridines into Allylic Amines.
Authors: Coote Susannah C. , O'Brien Peter 
Published: April 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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.