bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distortional Supramolecular Isomers of Polyrotaxane Coordination Polymers: Photoreactivity and Sensing of Nitro Compounds
Authors: Park In‐Hyeok , Medishetty Raghavender , Kim Ja‐Yeon , Lee Shim Sung , Vittal Jagadese J. 
Published: April 2014

AbstractDistortional isomers, or bond‐stretch isomers, differ only in the length of one or more bonds, which is due to crystallographic disorder in most cases. The term distortional isomerism is introduced to describe the structures of polyrotaxane 2D coordination polymers (CPs) that differ only by the relative positions in the neighboring entangled axles. A large ring and a long spacer ligand in 2D CPs yielded four different supramolecular isomers, of which two have an entangled polyrotaxane structure. One pair of CC bonds in the spacer ligand is well‐aligned in one isomer and undergoes [2+2] cycloaddition reaction, whereas the other isomer is photoinert. They also have different sensing efficiency for several aromatic nitro compounds. However, both isomers show selective PL quenching for the Brady’s reagent. Structurally similar supramolecular isomers with different photochemical reactivity and sensing abilities appear to be unprecedented.
Suffrutines A and B: A Pair of Z/E Isomeric Indolizidine Alkaloids from the Roots of Flueggea suffruticosa
Authors: Wu Zhen‐Long , Zhao Bing‐Xin , Huang Xiao‐Jun , Tang Gen‐Yun , Shi Lei , Jiang Ren‐Wang , Liu Xin , Wang Ying , Ye Wen‐Cai 
Published: April 2014

AbstractSuffrutines A (1) and B (2), a pair of novel photochemical Z/E isomeric indolizidine alkaloids, with a unique and highly conjugated C20 skeleton, were isolated from the roots of Flueggea suffruticosa. The structures were elucidated by extensive analysis of NMR spectra and single‐crystal X‐ray diffraction. The light‐induced isomerization and hypothetical biogenetic pathway to 1 and 2, as well as their activity for regulating the morphology of Neuro‐2a cells are also discussed.
A Concise and Versatile Synthesis of Alkaloids from Kopsia tenuis: Total Synthesis of (±)‐Lundurine A and B
Authors: Arai Shigeru , Nakajima Masaya , Nishida Atsushi 
Published: April 2014

AbstractA total synthesis of (±)‐lundurines A and B is described. These natural products have a unique hexacyclic skeleton which includes a cyclopropane‐fused indoline. A stereospecific construction of the pentasubstituted cyclopropane core was achieved, by radical cyclization using SmI2, with perfect stereoselectivity. Cyclizations to give seven‐ and five‐membered heterocycles, under palladium and ruthenium catalysis, respectively, accomplished the total syntheses. The late‐stage construction of the F ring by ring‐closing metathesis enabled access to the title compounds from a spiroindoline intermediate which is a common structure of other kopsia alkaloids.
Accelerating Spirocyclic Polyketide Synthesis using Flow Chemistry
Authors: Newton Sean , Carter Catherine F. , Pearson Colin M. , de C. Alves Leandro , Lange Heiko , Thansandote Praew , Ley Steven V. 
Published: April 2014

AbstractOver the past decade, the integration of synthetic chemistry with flow processing has resulted in a powerful platform for molecular assembly that is making an impact throughout the chemical community. Herein, we demonstrate the extension of these tools to encompass complex natural product synthesis. We have developed a number of novel flow‐through processes for reactions commonly encountered in natural product synthesis programs to achieve the first total synthesis of spirodienal A and the preparation of spirangien A methyl ester. Highlights of the synthetic route include an iridium‐catalyzed hydrogenation, iterative Roush crotylations, gold‐catalyzed spiroketalization and a late‐stage cis‐selective reduction.
Mechanically Interlocked Single‐Wall Carbon Nanotubes
Authors: de Juan Alberto , Pouillon Yann , Ruiz‐González Luisa , Torres‐Pardo Almudena , Casado Santiago , Martín Nazario , Rubio Ángel , Pérez Emilio M. 
Published: April 2014

AbstractExtensive research has been devoted to the chemical manipulation of carbon nanotubes. The attachment of molecular fragments through covalent‐bond formation produces kinetically stable products, but implies the saturation of some of the CC double bonds of the nanotubes. Supramolecular modification maintains the structure of the SWNTs but yields labile species. Herein, we present a strategy for the synthesis of mechanically interlocked derivatives of SWNTs (MINTs). In the key rotaxane‐forming step, we employed macrocycle precursors equipped with two π‐extended tetrathiafulvalene SWNT recognition units and terminated with bisalkenes that were closed around the nanotubes through ring‐closing metathesis (RCM). The mechanically interlocked nature of the derivatives was probed by analytical, spectroscopic, and microscopic techniques, as well as by appropriate control experiments. Individual macrocycles were observed by HR STEM to circumscribe the nanotubes.
Boron Perturbed Click Reactions Prompt Aromatic CH Activations
Authors: Winkelhaus Daniel , Stephan Douglas W. 
Published: April 2014

AbstractThe reaction of boron alkynes and boron azides leads to rare N3BC heterocycles resulting from aromatic CH activation of benzene and toluene. While subsequent treatment with PMe3 gave the PB adduct with the exocyclic boron, reaction with PtBu3 effected deprotonation of the heterocycle to give the corresponding phosphonium salt.
Elucidation of the Structure of Organic Solutions in Solvent Extraction by Combining Molecular Dynamics and X‐ray Scattering
Authors: Ferru Geoffroy , Gomes Rodrigues Donatien , Berthon Laurence , Diat Olivier , Bauduin Pierre , Guilbaud Philippe 
Published: April 2014

AbstractKnowledge of the supramolecular structure of the organic phase containing amphiphilic ligand molecules is mandatory for full comprehension of ionic separation during solvent extraction. Existing structural models are based on simple geometric aggregates, but no consensus exists on the interaction potentials. Herein, we show that molecular dynamics crossed with scattering techniques offers key insight into the complex fluid involving weak interactions without any long‐range ordering. Two systems containing mono‐ or diamide extractants in heptane and contacted with an aqueous phase were selected as examples to demonstrate the advantages of coupling the two approaches for furthering fundamental studies on solvent extraction.
Three‐Dimensional Protein Networks Assembled by Two‐Photon Activation
Authors: Gatterdam Volker , Ramadass Radhan , Stoess Tatjana , Fichte Manuela A. H. , Wachtveitl Josef , Heckel Alexander , Tampé Robert 
Published: April 2014

AbstractSpatial and temporal control over chemical and biological processes plays a key role in life and material sciences. Here we synthesized a two‐photon‐activatable glutathione (GSH) to trigger the interaction with glutathione S‐transferase (GST) by light at superior spatiotemporal resolution. The compound shows fast and well‐confined photoconversion into the bioactive GSH, which is free to interact with GST‐tagged proteins. The GSH/GST interaction can be phototriggered, changing its affinity over several orders of magnitude into the nanomolar range. Multiplexed three‐dimensional (3D) protein networks are simultaneously generated in situ through two‐photon fs‐pulsed laser‐scanning excitation. The two‐photon activation facilitates the three‐dimensional assembly of protein structures in real time at hitherto unseen resolution in time and space, thus opening up new applications far beyond the presented examples.
Flow‐Through Synthesis on Teflon‐Patterned Paper To Produce Peptide Arrays for Cell‐Based Assays
Authors: Deiss Frédérique , Matochko Wadim L. , Govindasamy Natasha , Lin Edith Y. , Derda Ratmir 
Published: April 2014

AbstractA simple method is described for the patterned deposition of Teflon on paper to create an integrated platform for parallel organic synthesis and cell‐based assays. Solvent‐repelling barriers made of Teflon‐impregnated paper confine organic solvents to specific zones of the patterned array and allow for 96 parallel flow‐through syntheses on paper. The confinement and flow‐through mixing significantly improves the peptide yield and simplifies the automation of this synthesis. The synthesis of 100 peptides ranging from 7 to 14 amino acids in length gave over 60 % purity for the majority of the peptides (>95 % yield per coupling/deprotection cycle). The resulting peptide arrays were used in cell‐based screening to identify 14 potent bioactive peptides that support the adhesion or proliferation of breast cancer cells in a 3D environment. In the future, this technology could be used for the screening of more complex phenotypic responses, such as cell migration or differentiation.
Tuning Al2O3Surface with SnO2to Prepare Improved Supports for Pd for CO Oxidation
Authors: Wang Xiang , Tian Jin Shu , Zheng Yu Hua , Xu Xiang Lan , Liu Wen Ming , Fang Xiu Zhong 
Published: April 2014

AbstractSnO2/Al2O3supports with different SnO2loadings were prepared by using a deposition–precipitation method and characterized by using N2and CO adsorption–desorption, XRD, H2temperature‐programmed reduction, and X‐ray photoelectron spectroscopy techniques. SnO2dispersed finely on the Al2O3surface with a capacity of 0.172 mmol 100 m−2, which equals 6.4 % SnO2loading. Below this loading, no crystalline SnO2can be detected owing to the formation of the sub‐monolayer‐ or monolayer‐dispersed SnO2phase. Crystalline SnO2can be observed only if the SnO2loading reaches 9 %. With use of these SnO2/Al2O3supports, all prepared Pd/SnO2/Al2O3catalysts demonstrate increased activity compared to Pd/SnO2and Pd/Al2O3owing to the presence of more active oxygen species on SnO2/Al2O3supports as well as their higher surface areas, which improve Pd dispersion. This result indicates that with SnO2/Al2O3supports, less amount of Pd can be used to obtain catalysts with competitive performance.
Synthesis and Solid‐State Structures of a Tetrathiafulvalene‐Conjugated Bistetracene
Authors: Yamashita Masataka , Kuzuhara Daiki , Aratani Naoki , Yamada Hiroko 
Published: April 2014

AbstractA tetrathiafulvalene (TTF)‐conjugated bistetracene was synthesized and characterized in the molecular electronic structures based on the spectroscopic measurements and the single‐crystal X‐ray diffraction analysis. UV/Vis absorption and electrochemical measurements of 5 revealed the considerable electronic communication between two tetracenedithiole units by through‐bond and/or through‐space interactions. The difference in the crystal‐packing structures of 5, showing polymorphism, results in a variety of intermolecular electronic‐coupling pattern. Of these, the π‐stacking structure of 5 A gave a large transfer integral of HOMOs (97 meV), which value is beyond hexacene and rubrene, thus, quite beneficial to achieve the high hole mobility.
Experimental and Theoretical Studies on Arene‐Bridged Metal–Metal‐Bonded Dimolybdenum Complexes
Authors: Carrasco Mario , Curado Natalia , Álvarez Eleuterio , Maya Celia , Peloso Riccardo , Poveda Manuel L. , Rodríguez Amor , Ruiz Eliseo , Álvarez Santiago , Carmona Ernesto 
Published: April 2014

AbstractThe bis(hydride) dimolybdenum complex, [Mo2(H)2{HC(N‐2,6‐iPr2C6H3)2}2(thf)2], 2, which possesses a quadruply bonded Mo2II core, undergoes light‐induced (365 nm) reductive elimination of H2 and arene coordination in benzene and toluene solutions, with formation of the MoI2 complexes [Mo2{HC(N‐2,6‐iPr2C6H3)2}2(arene)], 3⋅C6H6 and 3⋅C6H5Me, respectively. The analogous C6H5OMe, p‐C6H4Me2, C6H5F, and p‐C6H4F2 derivatives have also been prepared by thermal or photochemical methods, which nevertheless employ different Mo2 complex precursors. X‐ray crystallography and solution NMR studies demonstrate that the molecule of the arene bridges the molybdenum atoms of the MoI2 core, coordinating to each in an η2 fashion. In solution, the arene rotates fast on the NMR timescale around the Mo2‐arene axis. For the substituted aromatic hydrocarbons, the NMR data are consistent with the existence of a major rotamer in which the metal atoms are coordinated to the more electron‐rich CC bonds.
ChemInform Abstract: The Mixed‐Metal Tris(disulfide) Thiophosphate, KNb1.77Ta0.23PS10.
Authors: Lee Yoonjeong , Yoon Woojin , Yun Hoseop 
Published: April 2014

AbstractThe title compound is prepared by solid state reaction of Nb, Ta, P, and S (1:1:1:10) in a KCl flux (evacuated silica tube, 1073 K, 72 h, cooling to 473 K at a rate of 6 K/h, quenching).
ChemInform Abstract: Synthesis, Crystal Structure and Electronic Properties of the New Iron Selenide Ba9Fe4Se16.
Authors: Berthebaud David , Preethi Meher K. R. S. , Pelloquin Denis , Maignan Antoine 
Published: April 2014

AbstractThe new title compound is prepared from the elements (silica tube, 700 °C, 2 d) and characterized by powder XRD, TEM, and magnetic, resistivity, and dielectric measurements.
ChemInform Abstract: Synthesis, Structure, and Optical Properties of a Series of Quaternary Oxides, K2Ba(MO4)2 (M = Cr, Mo, W).
Authors: Chance W. Michael , zur Loye Hans‐Conrad 
Published: April 2014

AbstractSingle crystals of the title compounds are prepared from MoO3, WO3, or K2CrO4, and KOH and water, or KOH, NaOH, and water as hydroxide‐based hydrofluxes (autoclave, 230 °C, 12 h).
ChemInform Abstract: Mixed Close‐Packed Cobalt Molybdenum Nitrides as Non‐noble Metal Electrocatalysts for the Hydrogen Evolution Reaction.
Authors: Cao Bingfei , Veith Gabriel M. , Neuefeind Joerg C. , Adzic Radoslav R. , Khalifah Peter G. 
Published: April 2014

AbstractCo0.6Mo1.4N2 is synthesized by annealing CoMoO4 at 750 °C for 12 h under flowing NH3 followed by treatment at 400 °C for 1 h under flowing NH3.
ChemInform Abstract: Synergistic Lewis Base and Anion‐Binding Catalysis for the Enantioselective Vinylogous Addition of Deconjugated Butenolides to Allenoates.
Authors: Kumar Vikas , Mukherjee Santanu 
Published: April 2014

AbstractAn enantioselective vinylogous umpolung addition of deconjugated butenolides (I) and (IV) to allenoates (II) is achieved for the first time with the help of synergistic combination of an achiral phosphine and a chiral squaramide.
ChemInform Abstract: Direct Catalytic Asymmetric Addition of Acetonitrile to N‐Thiophosphinoylimines.
Authors: Kawato Yuji , Kumagai Naoya , Shibasaki Masakatsu 
Published: April 2014

AbstractSoft Lewis acid‐hard Broensted base cooperative catalysis to activate both acetonitrile (II) and phosphinoylimine (I) is found to be crucial to promote the elusive C—C bond‐forming reaction in an enantioselective fashion.
ChemInform Abstract: Asymmetric Organocatalytic Strecker‐Type Reactions of Aliphatic N,N‐Dialkylhydrazones.
Authors: Martinez‐Munoz Aurora , Monge David , Martin‐Zamora Eloisa , Marques‐Lopez Eugenia , Alvarez Eleuterio , Fernandez Rosario , Lassaletta Jose M. 
Published: April 2014

AbstractN,N‐Dialkylhydrazones (I) are subjected to a Strecker‐type reaction using TmsCN (II) as the cyanide source.
ChemInform Abstract: Palladium‐Catalyzed Synthesis of Benzofurans and Coumarins from Phenols and Olefins.
Authors: Sharma Upendra , Naveen Togati , Maji Arun , Manna Srimanta , Maiti Debabrata 
Published: April 2014

AbstractThe palladium‐catalyzed synthesis of benzofurans and coumarins by reacting phenols and unactivated olefins is described.
ChemInform Abstract: Pd‐Catalyzed Allylic Alkylation of Dienyl Carbonates with Nitromethane with High C‐5 Regioselectivity.
Authors: Yang Xiao‐Fei , Li Xiao‐Hui , Ding Chang‐Hua , Xu Chao‐Fan , Dai Li‐Xin , Hou Xue‐Long 
Published: April 2014

AbstractThe investigation reveals that the structure of the ligands as well as the steric effect of the substrate are crucial factors in determining the regiochemical outcome of the reaction.
ChemInform Abstract: Synthesis of β‐Ketonitriles, α,β‐Alkynones and Biscabinols from Esters Using tert‐Butoxide‐Assisted C(=O) (i.e., Acyl—C) Coupling under Ambient Conditions.
Authors: Kim Bo Ram , Lee Hyung‐Geun , Kang Seung‐Beom , Jung Kwang‐Ju , Sung Gi Hyeon , Kim Jeum‐Jong , Lee Sang‐Gyeong , Yoon Yong‐Jin 
Published: April 2014

AbstractA rapid, simple, and mild method for the metal‐free coupling reaction of esters with benzyl cyanides or acetylenes to give the title compounds is developed.
ChemInform Abstract: Sulfoxide‐to‐Sulfilimine Conversions: Use of Modified Burgess‐Type Reagents.
Authors: Hendriks Christine M. M. , Lamers Philip , Engel Julien , Bolm Carsten 
Published: April 2014

AbstractCompound (I) represents a new type of manageable Burgess reagent able to directly convert sulfoxides into sulfilimines.
ChemInform Abstract: Pd Nanoparticle‐Silica Nanotubes (Pd@SNTs) as an Efficient Catalyst for Suzuki—Miyaura Coupling and sp2 C—H Arylation in Water.
Authors: Park Ginam , Lee Sanghee , Son Sang Jun , Shin Seunghoon 
Published: April 2014

AbstractPd‐nanoparticles deposited inside silica nanotubes efficiently catalyze cross coupling reactions of aryl halide (II) and thiazoles (IV) with arylboronic acids in water.
ChemInform Abstract: Recyclable Fluorous Organocatalysts Promoted Three‐Component Reactions of Pyruvate, Aldehyde and Amine at Room Temperature.
Authors: Qian Jin‐long , Yi Wen‐bin , Cai Chun 
Published: April 2014

AbstractA new fluorous carbothioate acts as a catalyst in the synthesis of pyrrolones via cyclocondensation of aldehydes, pyruvate, and amines.
ChemInform Abstract: Synthesis of Indole Alkaloids Arsindoline A, Arsindoline B and Their Analogues in Low Melting Mixture.
Authors: Jella Rama Raju , Nagarajan Rajagopal 
Published: April 2014

AbstractThe low melting mixture of L‐tartaric acid and dimethyl urea acts as catalyst as well as solvent in the reaction of aldehydes and indoles.
ChemInform Abstract: A Visible‐Light‐Mediated Synthesis of Carbazoles.
Authors: Hernandez‐Perez Augusto C. , Collins Shawn K. 
Published: April 2014

AbstractThe photoredox oxidation to N‐aryl‐ and N‐alkyl‐bearing carbazoles utilizing continuous flow, visible light, and an in situ formed Cu‐based sensitizer is reported.
ChemInform Abstract: Facile Method for 1,3‐Dipolar Cycloaddition Reaction of Azomethine Ylides: Highly Stereoselective Synthesis of Substituted Pyrrolidine Derivatives.
Authors: Yavuz Serkan , Oezkan Hamdi , Tok Guelcin , Disli Ali 
Published: April 2014

AbstractEt2Zn‐catalyzed, solvent‐free 1,3‐dipolar cycloaddition of azomethine ylides, derived from aldehydes (I) and glycine ester (II), with N‐methylmaleimides gives pyrrolopyrrolidine derivatives (IV) with high endo‐selectivity.
ChemInform Abstract: Triphenylamine—Benzimidazole Derivatives: Synthesis, Excited‐State Characterization, and DFT Studies.
Authors: Pina Joao , Seixas de Melo J. Sergio , Batista Rosa M. F. , Costa Susana P. G. , Raposo M. Manuela M. 
Published: April 2014

AbstractThe high thermal stable triphenylamine benzimidazoles show strong fluorescence.
ChemInform Abstract: Visible‐Light‐Triggered Oxidative C—H Aryloxylation of Phenolic Amidines; Photocatalytic Preparation of 2‐Aminobenzoxazoles.
Authors: Srivastava Vishnu P. , Yadav Lal Dhar S. 
Published: April 2014

AbstractThe intramolecular cyclization of phenolic amidines proceeds in the presence of a ruthenium photoredox catalyst and air as terminal oxidant to give 2‐aminobenzoxazoles.
ChemInform Abstract: One‐Pot Synthesis of Pyridines from 3‐Aza‐1,5‐enynes.
Authors: Xin Xiaoyi , Wang Dongping , Li Xincheng , Wan Boshun 
Published: April 2014

AbstractA convenient one‐pot method allows the conversion of 3‐aza‐1,5‐enynes into pyridines via sequential aza‐Claisen rearrangement, 6π‐electrocyclization and elimination of aryl sulfinic acid.
ChemInform Abstract: A Facile Synthesis of 5‐Amino‐[1,2,3]triazolo[5,1‐a]isoquinoline Derivatives Through Copper‐Catalyzed Cascade Reactions.
Authors: Chen Yunfeng , Zhou Shilei , Ma Shan , Liu Wenqian , Pan Zhiquan , Shi Xaodong 
Published: April 2014

AbstractThe first synthesis of title compounds (III) using a 1,2,3‐triazole building block is reported.
ChemInform Abstract: Diastereoselective Synthesis of Dispirooxindoline Fused [1,3]Oxazines via Diels—Alder Reaction of Functionalized 1,2‐Dihydropyridines with (E)‐1,3‐Dihydro‐3‐phenacylidene‐2H‐indol‐2‐ones.
Authors: Sun Jing , Gong Hui , Yan Chao‐Guo 
Published: April 2014

AbstractA simple protocol is presented for the title Diels—Alder reaction that proceeds with high regio‐ and diastereoselectivity.
ChemInform Abstract: First I2—K2CO3‐Promoted Sequential C—N and C—O Bond Forming Approach for One‐Pot Synthesis of 1,4‐Benzoxazines.
Authors: Singh Sunil K. , Bajpai Anil K. , Saini Rajesh 
Published: April 2014

AbstractThe synthesis of benzoxazines (III) and (V) proceeds via in situ imine formation followed by intramolecular ring transformation cascades.
ChemInform Abstract: Phosphine‐Catalyzed [3 + 2] Cycloaddition of Morita—Baylis—Hillman Carbonates with Sulfamate‐Derived Cyclic Imines.
Authors: Zhang Lei , Yu Hao , Yang Zhilin , Liu Honglei , Li Zhen , Guo Junhong , Xiao Yumei , Guo Hongchao 
Published: April 2014

AbstractThe title reaction affords sulfamate‐fused dihydropyrroles (III) and (VI) in moderate to good yields.
ChemInform Abstract: Green Synthesis and Biological Evaluation of New Di‐α‐Aminophosphonate Derivatives as Cytotoxic Agents.
Authors: Rao Kunda Uma Maheswara , Namkoong Sim , Yu Hwan‐Chul , Park Junsoo , Chung Chan‐Moon , Oh Se Young 
Published: April 2014

AbstractTitle compounds (IV) are obtained by an one‐pot three‐component reaction under ultrasonic irradiation.
ChemInform Abstract: Novel Bicyclic Derivatives of 1,3‐Selenazine.
Authors: Proshin A. N. , Serkov I. V. , Lermontov A. S. , Shevtsova E. F. , Neganova M. E. , Bachurin S. O. 
Published: April 2014

AbstractNew bicyclic derivatives (IV) and (VI) can neither scavenge radicals nor affect the peroxide oxidation of lipids in rat brain homogenates.
Review of the Prospective Prediction of the 2014 Yutian Ms7.3 Earthquake in Xinjiang and Analysis of its Postseismic Trend
Authors: Si‐Qing QIN , Lei XUE , Pei LI , Guo‐Liang LI 
Published: April 2014

AbstractBased on the brittle failure theory of multiple locked patches in a seismogenic fault system and the associated prediction method developed by us, we have released a medium‐ and long‐term prediction of future strong earthquakes in the Yutian seismic zone of Xinjiang, including the magnitude, location, critical Benioff strain, and focal depth. Comparison shows that these parameters are almost identical with the Yutian Ms7.3 event in Xinjiang on 12 February 2014, which indicates that our previous prediction is credible. Meanwhile, our analysis suggest that the most immediate cause leading to Yutian Ms7.3 earthquake is attributed to the Yutian‐Cele ML 6.6 earthquake swarm in 2008.