bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transparent, Ultrahigh‐Gas‐Barrier Films with a Brick–Mortar–Sand Structure
Authors: Dou Yibo , Pan Ting , Xu Simin , Yan Hong , Han Jingbin , Wei Min , Evans David G. , Duan Xue 
Published: June 2015

AbstractTransparent and flexible gas‐barrier materials have shown broad applications in electronics, food, and pharmaceutical preservation. Herein, we report ultrahigh‐gas‐barrier films with a brick–mortar–sand structure fabricated by layer‐by‐layer (LBL) assembly of XAl‐layered double hydroxide (LDH, X=Mg, Ni, Zn, Co) nanoplatelets and polyacrylic acid (PAA) followed by CO2 infilling, denoted as (XAl‐LDH/PAA)n‐CO2. The near‐perfectly parallel orientation of the LDH “brick” creates a long diffusion length to hinder the transmission of gas molecules in the PAA “mortar”. Most significantly, both the experimental studies and theoretical simulations reveal that the chemically adsorbed CO2 acts like “sand” to fill the free volume at the organic–inorganic interface, which further depresses the diffusion of permeating gas. The strategy presented here provides a new insight into the perception of barrier mechanism, and the (XAl‐LDH/PAA)n‐CO2 film is among the best gas barrier films ever reported.
The Selective Cross‐Coupling of Secondary Alkyl Zinc Reagents to Five‐Membered‐Ring Heterocycles Using Pd‐PEPPSI‐IHeptCl
Authors: Atwater Bruce , Chandrasoma Nalin , Mitchell David , Rodriguez Michael J. , Pompeo Matthew , Froese Robert D. J. , Organ Michael G. 
Published: June 2015

AbstractThe ability to cross‐couple secondary alkyl centers is fraught with a number of problems, including difficult reductive elimination, which often leads to β‐hydride elimination. Whereas catalysts have been reported that provide decent selectivity for the expected (non‐rearranged) cross‐coupled product with aryl or heteroaryl oxidative‐addition partners, none have shown reliable selectivity with five‐membered‐ring heterocycles. In this report, a new, rationally designed catalyst, Pd‐PEPPSI‐IHeptCl, is demonstrated to be effective in selective cross‐coupling reactions with secondary alkyl reagents across an impressive variety of furans, thiophenes, and benzo‐fused derivatives (e.g., indoles, benzofurans), in most instances producing clean products with minimal, if any, migratory insertion for the first time.
Sequential Anion and Cation Exchange Reactions for Complete Material Transformations of Nanoparticles with Morphological Retention
Authors: Hodges James M. , Kletetschka Karel , Fenton Julie L. , Read Carlos G. , Schaak Raymond E. 
Published: June 2015

AbstractIon exchange reactions of colloidal nanocrystals provide access to complex products that are synthetically challenging using traditional hot‐injection methods. However, such reactions typically achieve only partial material transformations by employing either cation or anion exchange processes. It is now shown that anion and cation exchange reactions can be coupled together and applied sequentially in one integrated pathway that leads to complete material transformations of nanocrystal templates. Although the product nanocrystals do not contain any of the original constituent elements, the original morphology is retained, thereby fully decoupling morphology and composition control. The sequential anion/cation exchange process was applied to pseudo‐spherical CdO nanocrystals and ZnO tetrapods, producing fully transformed and shape‐controlled nanocrystals of copper and silver sulfides and selenides. Furthermore, hollow core–shell tetrapod ZnS@CdS heterostructures were readily accessible.
YAlC: A Bonding Chameleon with Heteropolyacetylene Features
Authors: Kotyrba Martin R. , Cuervo‐Reyes Eduardo , Nesper Reinhard 
Published: June 2015

AbstractYAlC was prepared by a flux method. It crystallizes as a partially filled‐up TlI structure, showing remarkable structural aspects at the border between Zintl phases and intermetallics. This novel ternary aluminide–carbide exhibits a unique one‐dimensional multi‐center bond and a polyacetylene‐related aluminum carbide substructure. The different functionalities of aluminum and of yttrium are quite remarkable. While the latter behaves more like a trivalent ion, aluminum contributes considerably to covalent bonding with carbon. Still yttrium d states contribute, but hardly in a directed manner.
A Dimetalloxycarbene Bonding Mode and Reductive Coupling Mechanism for Oxalate Formation from CO2
Authors: Paparo Albert , Silvia Jared S. , Kefalidis Christos E. , Spaniol Thomas P. , Maron Laurent , Okuda Jun , Cummins Christopher C. 
Published: June 2015

AbstractWe describe the stable and isolable dimetalloxycarbene [(TiX3)2(μ2‐CO2‐κ2C,O:κO′)] 5, where X=N‐(tert‐butyl)‐3,5‐dimethylanilide, which is stabilized by fluctuating μ2‐κ2C,O:κ1O′ coordination of the carbene carbon to both titanium centers of the dinuclear complex 5, as shown by variable‐temperature NMR studies. Quantum chemical calculations on the unmodified molecule indicated a higher energy of only +10.5 kJ mol−1 for the μ2‐κ1O:κ1O′ bonding mode of the free dimetalloxycarbene compared to the μ2‐κ2C,O:κ1O′ bonding mode of the masked dimetalloxycarbene. The parent cationic bridging formate complex [(TiX3)2(μ2‐OCHO‐κO:κO′)][B(C6F5)4], 4[B(C6F5)4], was simply deprotonated with the strong base K(N(SiMe3)2) to give 5. Complex 5 reacts smoothly with CO2 to generate the bridging oxalate complex [(TiX3)2(μ2‐C2O4‐κO:κO′′)], 6, in a CC bond formation reaction commonly anticipated for oxalate formation by reductive coupling of CO2 on low‐valent transition‐metal complexes.
Tissue distribution study of columbianadin and its active metabolite columbianetin in rats
Authors: Zhang You‐Bo , Yang Xiu‐Wei 
Published: June 2015

AbstractColumbianadin, one of the main bioactive constituents of the roots of Angelica pubescens Maxim. f. biserrata Shan et Yuan, has been found to possess obvious pharmacological effects in previous studies. In this study, a valid and sensitive reverse‐phase high‐performance liquid chromatography (RP‐HPLC) method was established and validated for the determination of columbianadin (CBN) and its active metabolite columbianetin (CBT) in rat tissue samples. Sample separation was performed on an RP‐HPLC column using a mobile phase of MeOH–H2O (75:25, v/v) at a flow rate of 1.0 mL/min. The UV absorbance of the samples was measured at the wavelength 325 nm. The calibration curves for CBN were linear over the ranges of 0.5–20 µg/g for brain, testes and muscle, 1.0–10.0 µg/g for stomach and intestine, and 0.2–20.0 µg/g for heart, liver, spleen, lung and kidney. The calibration curves for CBT were linear over the ranges of 0.5–25 µg/g for stomach and intestine, and 0.1–10.0 µg/g for heart, liver, spleen, lung and kidney. The analysis method was successfully applied to a tissue distribution study of CBN and CBT after intravenous administration of CBN to rats. The results of this study indicated that CBN could be detected in all of the selected tissues after i.v. administration. CBN was distributed to rat tissues rapidly and could be metabolized to CBT in most detected tissues. Of the detected tissues, heart had the highest uptake of CBN, which suggested that heart might be one of the main target tissues of CBN. Concentrations of CBT were obviously higher in the digestive system than in other assayed tissues. The information provided by this research is very useful for gaining knowledge of the capacities of CBN and CBT to access different tissues. Copyright © 2015 John Wiley & Sons, Ltd.
Coping strategies in a sample of anxiety patients: factorial analysis and associations with psychopathology
Authors: Pozzi Gino , Frustaci Alessandra , Tedeschi Daniela , Solaroli Silvia , Grandinetti Paolo , Di Nicola Marco , Janiri Luigi 
Published: June 2015

AbstractBackgroundThe relationship between coping styles and mental disorders has received considerable attention and instruments have been developed to assess coping strategies. The measurement by means of category systems has been criticized and a functional hierarchy of action types linked to the adaptive processes is preferred. We aimed to determine which factors may exist within the Brief‐COPE (Brief Coping Orientation to Problems Experienced – COPE – Inventory) in an Italian sample of patients with anxiety disorders; and if these factors correlate with the severity of psychopathology or with other characteristics.MethodsA total sample of 148 patients was recruited. The Brief‐COPE inventory, the Symptom Check List 90‐Revised, the Penn State Worry Questionnaire, the Zung Anxiety Status Inventory and the Zung Self‐Rating Anxiety Scale were administered.ResultsFactor analysis of the Brief‐COPE yielded nine factors accounting for 65.48% of the variance. Patients scored higher on Searching Support, followed by Acceptance, Changing Perspective, and Problem Solving. Associations between measures of psychopathology and factors of coping strategies, mostly Searching support and Avoidance, were found.ConclusionsData of the present study support a nine‐factor structure of the Brief‐COPE that includes five broad dimensions of coping. Psychopathology was mostly related to Searching support and Avoidance factors, showing that these strategies may reflect ineffective ways of coping; Problem solving and Changing perspective could be a valid approach to moderate anxiety/depression symptoms and psychopathology in general.
Discrepancy of target sites between clinician and cytopathological reports in head neck fine needle aspiration: Did I miss the target or did the clinician mistake the organ site?
Authors: Khanlari Mahsa , Daneshbod Yahya , Shaterzadeh Yazdi Hanieh , Shirian Sadegh , Negahban Shahrzad , Aledavood Azita , Oryan Ahmad , Khademi Bijan , Daneshbod Khosrow , Field Andrew 
Published: June 2015

AbstractThe diagnostic accuracy of fine needle aspiration cytology (FNAC) of head and neck lesions is relatively high, but cytologic interpretation might be confusing if the sample is lacking typical cytologic features according to labeled site by physician. These errors may have an impact on pathology search engines, healthcare costs or even adverse outcomes. The cytology archive database of multiple institutions in southern Iran and Australia covering the period 2001–2011, were searched using keywords: salivary gland, head, neck, FNAC, and cytology. All the extracted reports were reviewed. The reports which showed discordance between the clinician's impression of the organ involved and subsequent fine needle biopsy request, and the eventual cytological diagnosis were selected. The cytological diagnosis was confirmed by histology or cell block, with assistance from imaging, clinical outcome, physical examination, molecular studies, or microbiological culture. The total number of 10,200 head and neck superficial FNAC were included in the study, from which 48 cases showed discordance between the clinicians request and the actual site of pathology. Apart from the histopathology, the imaging, clinical history, physical examination, immunohistochemical study, microbiologic culture and molecular testing helped to finalize the target organ of pathology in 23, 6, 7, 8, 2, and 1 cases respectively. The commonest discrepancies were for FNAC of “salivary gland” [total: 20 with actual final pathology in: bone (7), soft tissue (5), lymph node (3), odontogenic (3) and skin (2)], “lymph node” [total: 12 with final pathology in: soft tissue (3), skin (3), bone (1) and brain (1)], “soft tissue” [total: 11 with final pathology in: bone (5), skin (2), salivary gland (1), and ocular region (1)] and “skin” [total: 5 with final pathology in: lymph node (2), bone (1), soft tissue (1) and salivary gland (1)]. The primary physician requesting FNAC of head and neck lesions are incorrect in their clinical impression of the actual site in nearly 0.5 percent of cases, due to the overlapping clinical and imaging findings or possibly due to inadequate history taking or physical examination.
Ansa‐Bridged Bis(benzene) Titanium Complexes
Authors: Braunschweig Holger , Brückner Charlotte , Celik Mehmet Ali , Dück Klaus , Hupp Florian , Kramer Thomas , Krebs Johannes , Krummenacher Ivo 
Published: June 2015

AbstractTaking advantage of an improved synthesis of [Ti(η6‐C6H6)2], we report here the first examples of ansa‐bridged bis(benzene) titanium complexes. Deprotonation of [Ti(η6‐C6H6)2] with nBuLi in the presence of N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine (pmdta) leads to the corresponding 1,1′‐dilithio salt [Ti(η6‐C6H5Li)2]⋅pmdta that enables the preparation of the first one‐ and two‐atom‐bridged complexes by simple salt metathesis. The ansa complexes were fully characterized (NMR spectroscopy, UV/Vis spectroscopy, elemental analysis, and X‐ray crystallography) and further studied electrochemically and computationally. Moreover, [Ti(η6‐C6H6)2] is found to react with the Lewis base 1,3‐dimethylimidazole‐2‐ylidene (IMe) to give the bent sandwich complex [Ti(η6‐C6H6)2(IMe)].
Rapid Asymmetric Transfer Hydroformylation (ATHF) of Disubstituted Alkenes Using Paraformaldehyde as a Syngas Surrogate
Authors: Fuentes José A. , Pittaway Rachael , Clarke Matthew L. 
Published: June 2015

AbstractAs an alternative to conventional asymmetric hydroformylation (AHF), asymmetric transfer hydroformylation (ATHF) by using formaldehyde as a surrogate for syngas is reported. A catalyst derived from commercially available [Rh(acac)(CO)2] (acac=acetylacetonate) and 1,2‐bis[(2S,5S)‐2,5‐diphenylphospholano]ethane(1,5‐cyclooctadiene) (Ph‐BPE) stands out in terms of both activity and enantioselectivity. Remarkably, not only are high selectivities achievable, the reactions are very simple to perform, and higher enantioselectivity (up to 96 % ee) and/or turnover frequencies than those achievable by using the same catalyst (or other leading catalysts) can be obtained by using typical conditions for AHF.
ChemInform Abstract: High‐Pressure Syntheses and Crystal Structures of Orthorhombic DyGaO3 and Trigonal GaBO3.
Authors: Vitzthum Daniela , Hering Stefanie A. , Perfler Lukas , Huppertz Hubert 
Published: June 2015

AbstractCompounds (III) and (VI) are synthesized in a Walker‐type multianvil apparatus and their structures are determined by single crystal XRD.
ChemInform Abstract: A Novel Dawson‐Like Cerium(IV)‐Hybridizing Selenotungstate Na13H7 [Ce(SeW17O59)2]·31H2O.
Authors: Li Hailou , Yang Wen , Chai Yun , Chen Lijuan , Zhao Junwei 
Published: June 2015

AbstractSingle crystals of Na13H7 [Ce(SeW17O59)2]·31H2O are prepared by reaction of Na2WO4 and Na2SeO3 with (NH4)2Ce(NO3)6 in an aqueous KCl‐containing solution at pH 2 (stirring, 30 min; 17% yield).
ChemInform Abstract: Flux Crystal Growth and Optical Properties of Two Uranium‐Containing Silicates: A2USiO6 (A: Cs, Rb).
Authors: Read Cory Michael , Smith Mark D. , Withers Ray , zur Loye Hans‐Conrad 
Published: June 2015

AbstractHigh‐quality single crystals of the title compounds are prepared by reaction of U3O8 and SiO2 in molten MF (M: Cs, Rb) acting as reactive flux (Ag crucibles, 900 °C, 12 h).
ChemInform Abstract: Synthesis, Crystal Structure and Characterization of Trivacant‐Keggin‐Polyoxometalate‐Based Carbonyl Manganese Derivative.
Authors: Liu Yinbao , Zhang Yanhui , Ma Pengtao , Dong Yongkang , Niu Jingyang , Wang Jingping 
Published: June 2015

Abstract(NH4)3H3 [{Mn(CO)3}(Mn(H2O)2)(Mn (H2O)3) (TeW9O33)]2·31H2O (I) is prepared by reaction of Na8(TeW9O33) with MnCl2 (70 °C, 20 min) followed by addition of Mn(CO)5Br in MeCN (70 °C, 1 h; 16% yield).
ChemInform Abstract: Crystal Structure, Transport, and Magnetic Properties of an Ir6+ Compound Ba8Al2IrO14.
Authors: Roennow Henrik M. , et al.  
Published: June 2015

AbstractSingle crystals of the new title compound are prepared by reaction of BaCO3, IrO2, and Y2O3 powder by the self‐flux method in Al2O3 crucibles (1250 °C, 2 h).
ChemInform Abstract: Flux Crystal Growth of the Ternary Polygermanide LaPtGe2, a p‐Type Metal.
Authors: Bugaris Daniel E. , Sturza Mihai , Han Fei , Im Jino , Chung Duck Young , Freeman Arthur J. , Kanatzidis Mercouri G. 
Published: June 2015

AbstractPlate‐like crystals of LaPtGe2 are grown from a stoichiometric melt of the elements in an In flux (Al2O3 crucible in evacuated silica tubes, 1.
ChemInform Abstract: Lewis Acid Template‐Catalyzed Asymmetric Diels—Alder Reaction.
Authors: Ishihara Jun , Nakadachi Shino , Watanabe Yuki , Hatakeyama Susumi 
Published: June 2015

AbstractAn enantioselective Diels—Alder reaction of 2,4‐dienols and methyl acrylate is developed using a chiral Zn(II)/Mg(II) octahydro‐BINOL complex as catalytic system.
ChemInform Abstract: Organocatalytic Conjugate Addition of Cyclopropylacetaldehyde Derivatives to Nitro Olefins: En Route to β‐ and γ‐Amino Acids.
Authors: Kaasik Mikk , Noole Artur , Reitel Kaert , Jaerving Ivar , Kanger Tonis 
Published: June 2015

AbstractA new, general and straightforward route to β‐ and γ‐amino acid precursors by an asymmetric Michael reaction is developed.
ChemInform Abstract: Cycloisomerization of Allene—Enol Ethers under Bi(OTf)3 Catalysis.
Authors: Ondet Pierrick , Joffrin Amelie , Diaf Ilhem , Lemiere Gilles , Dunach Elisabet 
Published: June 2015

AbstractBi(OTf)3 selectively promotes the activation of the enol ether moiety of the substrate accessing interesting functionalized cyclopentene rings.
ChemInform Abstract: Regioselective C—H Bond Amination by Aminoiodanes.
Authors: Kantak Abhishek A. , Marchetti Louis , DeBoef Brenton 
Published: June 2015

Abstract2‐Phenylpyridines (I) and (IV) are site‐ and regioselectively aminated at the ortho‐position of the phenyl moiety using phthalimide‐ and saccharin‐derived iodanes (II) and (VI).
ChemInform Abstract: Iron Achieves Noble Metal Reactivity and Selectivity: Highly Reactive and Enantioselective Iron Complexes as Catalysts in the Hydrosilylation of Ketones.
Authors: Bleith Tim , Wadepohl Hubert , Gade Lutz H. 
Published: June 2015

AbstractThe first Fe‐catalyzed enantioselective hydrosilylation for a broad range of aryl and alkyl ketones is presented.
ChemInform Abstract: Dehydrogenative and Decarboxylative C—H Alkynylation of Heteroarenes Catalyzed by Pd(II)—Carbene Complex.
Authors: Parsharamulu Thupakula , Vishnuvardhan Reddy Police , Likhar Pravin R. , Lakshmi Kantam Mannepalli 
Published: June 2015

AbstractThe air‐ and moisture‐stable palladium catalyst catalyzes the cross‐coupling of azoles with terminal alkynes or aryl propiolic acids to afford C‐2 alkenylated products.
ChemInform Abstract: Efficient Oxa‐Diels—Alder/Semipinacol Rearrangement/Aldol Cascade Reaction: Short Approach to Polycyclic Architectures.
Authors: Peng Jin‐Bao , Qi Yue , Jing Ze‐Ran , Wang Shao‐Hua , Tu Yong‐Qiang , Zhu Dao‐Yong , Zhang Fu‐Min 
Published: June 2015

AbstractA novel carbon electrophile induced intermolecular oxa‐Diels—Alder/semipinacol rearrangement/aldol cascade reaction of allylic silyl ether with β,γ‐unsaturated α‐ketoester is developed under the promotion of SnCl4.
ChemInform Abstract: Expeditious One‐Pot Three Component Synthesis of N‐Aryl Dithiocarbamate Derivatives Using Mesoporous Cu‐Materials.
Authors: Payra Soumen , Saha Arijit , Peng Rui , Wu Chia‐Ming , Koodali Ranjit T. , Banerjee Subhash 
Published: June 2015

AbstractIt is demonstrated, that copper supported on MCM‐48 efficiently catalyzes the reaction of aromatic amines, carbon disulfide, and esters or amides to form dithiocarbamates in short reaction times and under mild conditions.
ChemInform Abstract: Reaction of Cyclopropenes with a Trichloromethyl Radical: Unprecedented Ring‐Opening Reaction of Cyclopropanes with Migration.
Authors: Ueda Masafumi , Doi Nobuyoshi , Miyagawa Hitoki , Sugita Shoichi , Takeda Norihiko , Shinada Tetsuro , Miyata Okiko 
Published: June 2015

AbstractThe direct addition reaction of chloroform to cyclopropenes in presence of triethylborane as initiator gives trichloromethylated cyclopropanes in good yields.
ChemInform Abstract: Stereoselective Synthesis of Highly Substituted Cyclohexanes by a Rhodium‐Carbene Initiated Domino Sequence.
Authors: Parr Brendan T. , Davies Huw M. L. 
Published: June 2015

AbstractThe reaction cascade features a tandem ylide formation/[2,3]‐sigmatropic rearrangement, oxy‐Cope rearrangement, and type II carbonyl ene reaction, all of which proceed with a high degree of stereocontrol.
ChemInform Abstract: Direct Organocatalytic Oxo‐Metathesis, a trans‐Selective Carbocation‐Catalyzed Olefination of Aldehydes.
Authors: Naidu Veluru Ramesh , Bah Juho , Franzen Johan 
Published: June 2015

AbstractThe presented reaction is catalyzed by the Lewis acid tritylium tetrafluoroborate and utilizes unactivated alkenes for the olefination of aromatic aldehydes to give trans β‐alkylstyrenes with only acetone as the by‐product.
ChemInform Abstract: Rhodium‐Catalyzed Regioselective Direct C—H Amidation of 2,4‐Diarylquinazoline with Sulfonyl Azides: An Example of Steric Hindrance Regulated Mono‐ and Diamidation Selectivity.
Authors: Zhang Chunyan , Zhou Yirong , Deng Zhihong , Chen Xin , Peng Yiyuan 
Published: June 2015

AbstractAn unprecedented steric hindrance controlled regioselective rhodium‐catalyzed direct C—H amidation of 2,4‐diarylquinazoline is described.
ChemInform Abstract: A Ruthenium‐Based Catalytic System for a Mild Borrowing‐Hydrogen Process.
Authors: Jumde Varsha R. , Gonsalvi Luca , Guerriero Antonella , Peruzzini Maurizio , Taddei Maurizio 
Published: June 2015

AbstractAromatic amines can be easily alkylated with aliphatic and benzylic alcohols using a commercially available Ruthenium catalyst together with 1,3,5‐triaza‐7‐phosphaadamantane.
ChemInform Abstract: One‐Pot Synthesis of Aryl Sulfones from Organometallic Reagents and Iodonium Salts.
Authors: Margraf Natalie , Manolikakes Georg 
Published: June 2015

AbstractThe arylation is carried out in the absence of transition metals and applied to a broad spectrum of lithium, magnesium, and zinc sulfinates under different conditions as is exemplified by sulfone (III).
ChemInform Abstract: Synthesis of Unsymmetrical Ureas and S‐Thiocarbamates under Catalyst‐Free Conditions in a [BMIM]BF4 Ionic Liquid.
Authors: Hosseinzadeh Rahman , Tajbakhsh Mahmood , Aghili Nora 
Published: June 2015

AbstractTitle compounds are synthesized by direct condensation of phenylurea with primary and secondary amines or thiols.
ChemInform Abstract: tert‐Butyl Phenyl Sulfoxide: A Traceless Sulfenate Anion Precatalyst.
Authors: Zhang Mengnan , Jia Tiezheng , Sagamanova Irina K. , Pericas Miquel A. , Walsh Patrick J. 
Published: June 2015

AbstractThe title compound catalyzes the homocoupling of benzyl halides to trans‐stilbenes in good to excellent yields.
ChemInform Abstract: Enantioselective Desymmetrization via Carbonyl‐Directed Catalytic Asymmetric Hydroboration and Suzuki—Miyaura Cross‐Coupling.
Authors: Hoang Gia L. , Yang Zhao‐Di , Smith Sean M. , Pal Rhitankar , Miska Judy L. , Perez Damaris E. , Pelter Libbie S. W. , Zeng Xiao Cheng , Takacs James M. 
Published: June 2015

AbstractThe title desymmetrization affords chiral secondary organoboronates, which are transformed to enantioenriched cyclopentanols.
ChemInform Abstract: Oxidative Heck Desymmetrization of 2,2‐Disubstituted Cyclopentene‐1,3‐diones.
Authors: Walker S. E. , Lamb C. J. C. , Beattie N. A. , Nikodemiak P. , Lee A.‐L. 
Published: June 2015

AbstractOxidative Heck couplings of 2,2‐disubstituted cyclopentene‐1,3‐diones (I) are reported for the first time.
ChemInform Abstract: Transition‐Metal‐Free Intramolecular Carbene Aromatic Substitution/Buechner Reaction: Synthesis of Fluorenes and [6,5,7]Benzo‐Fused Rings.
Authors: Liu Zhenxing , Tan Haocheng , Wang Long , Fu Tianren , Xia Ying , Zhang Yan , Wang Jianbo 
Published: June 2015

AbstractA simple and efficient method to access fluorenes and [6,5,7]benzo‐fused rings through transition‐metal‐free intramolecular aromatic substitution/Buechner reaction, using N‐tosylhydrazones as non‐stabilized diazo compound precursors is developed.