bluuebunny/crossref_metadata_2025 huggingface dataset:
Solvent Dependent Dehydrating Condensation of Benzylsulfonyl Acetic Acids.
Authors: Reddy N. Srinivasa , Reddy E. Premkumar , Reddy M. V. Ramana
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Microwave‐Enhanced Reduction of Nitro and Azido Arenes to N‐Arylformamides Employing Zn—HCOONH4: Synthesis of 4(3H)‐Quinazolinones and Pyrrolo[2,1‐c][1,4]benzodiazepines.
Authors: Kamal Ahmed , Reddy K. Srinivasa , Prasad B. Rajendra , Babu A. Hari , Ramana A. Venkata
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Characterization of the Chiral Paramagnetic Multispin System Built on a Cyclotriphosphazene Scaffold.
Authors: Shimono Satoshi , Tamura Rui , Ikuma Naohiko , Takahashi Hiroki , Sakai Naoko , Yamauchi Jun
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Hydrazinium Monoformate Mediated Facile Preparation of Amines from Azides Catalyzed by Zinc.
Authors: Prasad H. S. , Srinivasa G. R. , Abiraj K. , Gowda D. Channe
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Deoxyfluorination of Alcohols Using N,N‐Diethyl‐α,α‐difluoro‐(m‐methylbenzyl)amine.
Authors: Kobayashi Shingo , Yoneda Atushi , Fukuhara Tsuyoshi , Hara Shoji
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Palladium‐Catalyzed Cyanation of Aryl Bromides Promoted by Low‐Level Organotin Compounds.
Authors: Yang Chunhua , Williams J. Michael
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Dioxygen‐Promoted Regioselective Oxidative Heck Arylations of Electron‐Rich Olefins with Arylboronic Acids.
Authors: Andappan Murugaiah M. S. , Nilsson Peter , von Schenck Henrik , Larhed Mats
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Superelectrophilic Activation of Polyfunctional Organic Compounds Using Zeolites and Other Solid Acids.
Authors: Koltunov Konstantin Yu. , Walspurger Stephane , Sommer Jean
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Conversion of α‐Haloaldehydes into Acylating Agents by an Internal Redox Reaction Catalyzed by Nucleophilic Carbenes.
Authors: Reynolds Nathan T. , Read de Alaniz Javier , Rovis Tomislav
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Generation and Utility of Tertiary α‐Aminoorganolithium Reagents.
Authors: Wolckenhauer Scott A. , Rychnovsky Scott D.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Highly Stereoselective Approach to Alk‐2‐yne‐1,4‐diols by Oxazaborolidine‐Mediated Reduction of Alk‐2‐yne‐1,4‐diones.
Authors: Ariza Xavier , Bach Jordi , Berenguer Ramon , Farras Jaume , Fontes Montserrat , Garcia Jordi , Lopez Marta , Ortiz Jordi
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Rhodium‐Catalyzed 1,4‐Addition of Terminal Alkynes to Vinyl Ketones.
Authors: Lerum Ronald V. , Chisholm John D.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Sulfamic Acid as a Cost‐Effective Catalyst Instead of Metal‐Containing Acids for Acetolysis of Cyclic Ethers.
Authors: Wang Bo , Gu Yanlong , Gong Weizhong , Kang Yuru , Yang Liming , Suo Jishuan
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Asymmetric Lithium(I) and Copper(II) Alkoxy‐N‐heterocyclic Carbene Complexes; Crystallographic Characterization and Lewis Acid Catalysis.
Authors: Arnold Polly L. , Rodden Mark , Davis Kate M. , Scarisbrick Andrew C. , Blake Alexander J. , Wilson Claire
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Nickel‐Catalyzed Intermolecular [3 + 2 + 2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes.
Authors: Saito Shinichi , Masuda Manami , Komagawa Shinsuke
Published: November 2004

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Mild and Efficient Allylation of Aldehydes Mediated by Titanium(III) Chloride.
Authors: Jana Samaresh , Guin Chandrani , Roy Subhas Chandra
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
A Practical and Efficient Preparation of (S)‐2‐Benzylsuccinic Acid: A Key Acid Synthon of KAD‐1229.
Authors: Liu Jian‐Chao , Yang Yu‐She , Ji Ru‐Yun
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Ruthenium Catalyzed Addition Reaction of Carboxylic Acid Across Olefins Without β‐Hydride Elimination.
Authors: Oe Yohei , Ohta Tetsuo , Ito Yoshihiko
Published: November 2004

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Reductive Cleavage of S—S Bond by Zn/AlCl3 System: A Novel Method for the Synthesis of Sulfides from Alkyl Tosylates and Disulfides.
Authors: Movassagh Barahman , Mossadegh Amir
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Discovery of Potent and Orally Bioavailable N,N′‐Diarylurea Antagonists for the CXCR2 Chemokine Receptor.
Authors: Jin Qi , et al. et al.
Published: November 2004

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Efficient Catalyst for the Suzuki—Miyaura Coupling of Potassium Aryl Trifluoroborates with Aryl Chlorides.
Authors: Barder Timothy E. , Buchwald Stephen L.
Published: November 2004

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Simple and Efficient Protocol for Catalyst Recycling and Product Recovery in the Pd‐Catalyzed Homogeneous Suzuki Reaction.
Authors: Nobre Sabrina M. , Wolke Silvana I. , da Rosa Ricardo G. , Monteiro Adriano L.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
First Planar Chiral Bidentate Ligand Based on a (η5‐Cyclopentadienyl)(η4‐cyclobutadiene) Cobalt Backbone: High Efficiency in Enantioselective Palladium‐Catalyzed Allylic Substitutions.
Authors: Gomez Arrayas Ramon , Garcia Mancheno Olga , Carretero Juan C.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Asymmetric Synthesis of trans‐3‐Amino‐4‐alkylazetidin‐2‐ones from Chiral N,N‐Dialkylhydrazones.
Authors: Diez Elena , Fernandez Rosario , Marques‐Lopez Eugenia , Martin‐Zamora Eloisa , Lassaletta Jose M.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Metal‐Assisted Synthesis of Enantiopure Spirocyclic β‐Lactams from Azetidine‐2,3‐diones.
Authors: Alcaide Benito , Almendros Pedro , Martinez‐del Campo Teresa , Rodriguez‐Acebes Raquel
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Novel Thiophenes and Analogues with Anthelmintic Activity Against Haemonchus contortus.
Authors: Gonzalez Isabel C. , Davis Leon N. , Smith Charles K. II
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
New Synthesis of 3H‐Benzo[b]thiophen‐2‐ones.
Authors: Kamila Sukanta , Biehl Edward R.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Ring Size Influence on the Cyclocondensation Mode of GABA — Nitrile Imine Adducts.
Authors: Abu Thaher Bassam A. , Zahra Jalal A. , El‐Abadelah Mustafa M. , Voelter W.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Preparative Synthesis of 7‐Carboxy‐2‐R‐isoindol‐1‐ones.
Authors: Varlamov A. V. , Boltukhina E. V. , Zubkov F. I. , Sidorenko N. V. , Chernyshev A. I. , Grudinin D. G.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Investigations in the Area of Amines and Ammonium Compounds. Part 237. Synthesis of 2,2‐Dialkyl‐4‐hydroxymethylbenzo[f]isoindolinium and 2,2‐Dialkyl‐4‐hydroxymethylisoindolinium Salts.
Authors: Chukhadzhyan E. O. , Gevorkyan. A. R. Gevorkyan. A. R. , Chukhadzhyan El. O. , Shakhatuni K. G. , Kinoyan F. S. , Panosyan G. A.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Regioselective N‐Vinylation of Cyclic Thionocarbamates Through a Vinyl Bis‐Sulfone Methodology.
Authors: Girniene Jolanta , Tardy Sebastien , Tatibouet Arnaud , Sackus Algirdas , Rollin Patrick
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Regioselective Synthesis of Thieno[3,2‐c][1]benzopyran‐4‐ones by Thio‐Claisen Rearrangement
Authors: Majumdar Krishna C. , Biswas Anindita
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Competitive Photochemical Pathways in the Rearrangement of Tetrasubstituted 4H‐Thiopyrans.
Authors: Pirelahi Hooshang , Atarodiekashani Assieh , Seyyedmoossavi Seyyedmajid , Daryanavardedargahani Hossein
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Diels—Alder Cycloaddition of 2‐Azadienes to Methyl 2‐(2,6‐Dichlorophenyl)‐2H‐azirine‐3‐carboxylate in the Synthesis of Methyl 4‐Oxo‐1,3‐diazabicyclo[4.1.0]heptane‐6‐carboxylates.
Authors: Alves M. Jose , Duraes M. Miguel , Fortes A. Gil
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Reactions of 3,4‐Dichloro‐N‐R‐maleimides with Substituted 2‐Thiouracils.
Authors: Volovenko Yu. M. , Dubnina G. G. , Chernega A. N.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis of 1,6‐Polymethylene Pyrimidines Based on 4‐(1‐Azacycloalkylidine)‐1,3‐oxazol‐5‐ones.
Authors: Nazarenko K. G. , Shvidenko K. V. , Tolmachev A. A.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Carbon Disulfide in Synthesis of Thiazolo[3,4‐a]quinoxalines Based on 3‐(α‐Chlorobenzyl)quinoxalin‐2‐(1H)‐ones.
Authors: Kalinin A. A. , Mamedov V. A.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
An Efficient and Facile One‐Pot Synthesis of Structurally Unique 2,4,6‐Tris(arylchalcogeno)‐1,3,5‐triazine and 1,3,5‐Tris(arylchalcogeno)‐2,4,6‐trimethylbenzene.
Authors: Milton Marilyn Daisy , Kumar Naveen , Sokhi Sarbjot Singh , Singh Sarika , Singh Jai Deo
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Two New Diterpenoids from Isodon japonica.
Authors: Bai Suping , Jin Xiaoling , Yang Li
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
A New Environment‐Sensitive Fluorescent Amino Acid for Fmoc‐Based Solid Phase Peptide Synthesis.
Authors: Vazquez M. Eugenio , Rothman Deborah M. , Imperiali Barbara
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Substituted 1,2‐Thiazetidine 1,1‐Dioxides. Synthesis of (RS)‐ and (S)‐1,2‐Thiazetidine‐3‐acetic Acid 1,1‐Dioxide and Its Reactions with Amino Acids and Dipeptides.
Authors: Roehrich Till , Thaher Bassam Abu , Manicone Nico , Otto Hans‐Hartwig
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Unprecedented Stereospecific Synthesis of a Novel Tetracyclic Ring System, a Hybrid of Tetrahydropyrrolo[2,3‐b]indole and Tetrahydroimidazo[1,2‐a]indole, via a Domino Reaction upon a Tryptophan‐Derived Amino Nitrile.
Authors: Gonzalez‐Vera Juan A. , Garcia‐Lopez M. Teresa , Herranz Rosario
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Total Synthesis of Suaveoline and Norsuaveoline via Intramolecular Oxazole—Olefin Diels—Alder Reaction.
Authors: Ohba Masashi , Natsutani Itaru , Sakuma Takashi
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
A Benzyloxy Group Migration under Mitsunobu Reaction Conditions.
Authors: Marsac Yoann , Nourry Arnaud , Legoupy Stephanie , Pipelier Muriel , Dubreuil Didier , Huet Francois
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Biological Activity of 22‐Oxa CD‐Ring Modified Analogues of 1α,25‐Dihydroxyvitamin D3: Spiro[5.5]undecane CF‐Ring Analogues.
Authors: Schepens Wim , Van Haver Dirk , Vanderwalle Maurits , De Clercq Pierre J. , Bouillon Roger , Verstuyf Annemieke
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Studies on the Synthesis of Landomycin A. Synthesis of the Originally Assigned Structure of the Aglycone, Landomycinone, and Revision of Structure.
Authors: Roush William R. , Neitz R. Jeffrey
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Stereochemistry of Isoplagiochin C, a Macrocyclic Bisbibenzyl from Liverworts.
Authors: Bringmann Gerhard , Muehlbacher Joerg , Reichert Matthias , Dreyer Michael , Kolz Juergen , Speicher Andreas
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Spirastrellolide A: Revised Structure, Progress Toward the Relative Configuration, and Inhibition of Protein Phosphatase 2A.
Authors: Williams David E. , Lapawa Marshall , Feng Xidong , Tarling Tamsin , Roberge Michel , Andersen Raymond J.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
The Isolation of Uncomplexed P42‐
Authors: Seppelt K.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Organotin(IV)n+ Complexes Formed with Biologically Active Ligands
Authors: Nagy L. , Szorcsik A. , Schrantz K. , Sletten J. , Kamu E. , Jankovics H. , Jancso A. , Scopelliti M. , Deak A. , Pellerito L.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
1,3‐Dithiolo[4,5‐d]pyrimidines: Synthesis and Properties
Authors: Neilands O.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Thiocarbonyl Compounds from β‐Substituted Vinylald‐ and ‐Ketimmonium Derivatives
Authors: Timokhina Lyudmila , Voronkov Mikhail
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Three‐Membered Benzylic Thia Rings of Polycyclic Aromatic Hydrocarbons: Synthesis, Molecular Calculations and Properties
Authors: Zoller Uri
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Preparation and Synthetic Use of Enantiopure Naphthalene Dihydrodiols
Authors: Sello G. , Orsini F.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Mannich Reaction
Authors: Kobayashi Shu , Ueno Masaharu
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
A Survey of Computational and Physical Methods Applied to Solid‐State Fermentation
Authors: Lenz J. , Hoefer M. , Krasenbrink J.‐B. , Hoelker U.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Biochemical Engineering of Solid‐State Fermentation
Authors: Weber F. J. , Oostra J. , Nagel F. J. I. , Schutyser M. A. I. , Hoogschagen M. J. , Rahardjo Y. S. P. , Zhu Y. , Boom R. M. , Tramper J. , Rinzema A.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Olefin Epoxidation with Inorganic Peroxides. Solutions to Four Long‐Standing Controversies on the Mechanism of Oxygen Transfer
Authors: Deubel Dirk V. , Frenking Gernot , Gisdakis Philip , Herrmann Wolfgang A. , Roesch Notker , Sundermeyer Joerg
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Photoprocesses in Microaggregates
Authors: Quina Frank H. , Lissi Eduardo A.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Comparisons Between Mammalian and Artificial Olfaction Based on Arrays of Carbon Black—Polymer Composite Vapor Detectors
Authors: Lewis Nathan S.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
Vibrational and Electronic Spectra of Neutral and Ionic Combustion Reaction Intermediates Trapped in Rare‐Gas Matrixes
Authors: Jacox Marilyn E.
Published: November 2004

For Abstract see ChemInform Abstract in Full Text.
One‐Pot Synthesis of Pyridyltellurium Derivatives from a Reaction with Isopropylmagnesium Chloride and X‐ray Crystal Structures of Various Pyridyl Ditellurides
Authors: Bhasin Kuldip K. , Arora Veena , Klapötke Thomas M. , Crawford Margaret‐Jane
Published: November 2004

A one‐pot synthesis of various symmetrical and unsymmetrical 2‐pyridyl‐, 2‐bromo‐5‐pyridyl‐, and 2,5‐dibromo‐3‐pyridyltellurium compounds has been carried out, at room temperature, by selective single bromine‐magnesium exchange of 2‐bromo‐, 2,5‐dibromo‐ and 2,3,5‐tribromopyridine, respectively, with isopropylmagnesium chloride. This exchange reaction gives the corresponding pyridylmagnesium chlorides, which, upon insertion of elemental tellurium (activated), give the pyridyltelluromagnesium chlorides, and, subsequently, the corresponding dipyridyl ditellurides upon aerial oxidation. The pyridyltelluromagnesium chlorides give unsymmetrical pyridyltellurium derivatives in good yield upon treatment with alkyl halides. The X‐ray crystal structures of bis(2‐pyridyl) ditelluride, bis(2,5‐dibromo‐6‐methyl‐3‐pyridyl) ditelluride and bis(2,5‐dibromo‐3‐pyridyl) ditelluride are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
The Anderson‐Type Anion (TeMo6O24)6− − A Multidentate Ligand for Trivalent Rare Earth Cations
Authors: Drewes Daniel , Limanski Eva Melanie , Krebs Bernt
Published: November 2004

The syntheses and structural characterizations of four novel lanthanide polyoxomolybdates containing the Anderson‐type anion (TeMo6O24)6− are presented. Depending on the size of the trivalent rare earth cations, in the solid‐state structures of {[La(H2O)6]2(TeMo6O24)}n·6nH2O (1), {[Ce(H2O)7]2(TeMo6O24)}n·7nH2O (2), {[Pr(H2O)7]2(TeMo6O24)}n·8nH2O (3) and {[Nd(H2O)7]2(TeMo6O24)}n·8nH2O (4) two different arrangements of the building unit are present. The (TeMo6O24)6− anion acts as a hexadentate ligand for LaIII and as a tetradentate ligand for CeIII, PrIII and NdIII, leading to two different infinite one‐dimensional chains. The crystal structures of the new compounds are compared with known lanthanide polyoxomolybdates containing the (TeMo6O24)6− anion and the influence of the LnIII ionic radii is discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of 1,3,5,2λ5‐Triazaphosphinines by Intramolecular Cyclisation of (N‐Cyanophosphorimidoyl)guanidines and Diguanidinophosphonium Chlorides
Authors: Inguimbert Nicolas , Jäger Lothar , Taillefer Marc , Biedermann Matthias , Cristau Henri‐Jean
Published: November 2004

The sodium phosphonium diylide Na[Ph2P(NCN)2] (3) − the first example of a stabilised phosphonium diylide − was synthesised by treatment of sodium diphenylphosphide with 2 equiv. of cyanic azide. Compound 3 reacted with alkyl‐ and arylammonium salts [RR′NH2]Cl {R = PhCH2, tBu, Ph; R′ = H; RR′ = −[(CH2)2O(CH2)2]−}. Depending on the molar ratios (1:1 or 1:2), (N‐cyano‐P,P‐diphenylphosphorimidoyl)guanidines Ph2P(NCN)N=C(NH2)NRR′ (8) or diguanidinodiphenylphosphonium chlorides [Ph2P{N=C(NH2)NRR′}2]Cl (10) were formed. When molten, compounds 8 yielded new cyclic 1,3,5,2λ5‐triazaphosphinines 11. The fusion of compound 10 allowed the formation of the same 1,3,5,2λ5‐triazaphosphinines 11, along with the formation of NH4Cl or [PhNH3]Cl. A crystal structure analysis of 4‐amino‐6‐morpholino‐2,2‐diphenyl‐1,3,5,2λ5‐triazaphosphinine (11a) revealed an almost planar six‐membered ring for the 1,3,5,2λ5‐triazaphosphinine template. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of Thioglycosides by Tetrathiomolybdate‐Mediated Michael Additions of Masked Thiolates
Authors: Sridhar Perali Ramu , Prabhu Kandikere Ramaiah , Chandrasekaran Srinivasan
Published: November 2004

An efficient one‐pot methodology for the synthesis of thioglycosides in excellent yields under neutral conditions through the use of benzyltriethylammonium tetrathiomolybdate [(BnNEt3)2MoS4; 1] as a sulfur‐transfer reagent has been developed. The reagent 1 reacts with sugar halides to give sugar disulfides, which then undergo reductive cleavage in situ to provide the corresponding thiolates, followed by Michael addition to give the corresponding thioglycosides. Further, the utility of this one‐pot reaction in aqueous medium has been exemplified through the use of ammonium tetrathiomolybdate [(NH4)2 MoS4; 2]. The application of this methodology has been extended to the synthesis of a variety of thiosugar analogues with excellent diastereoselectivity through inter‐ and intramolecular reactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis and Conformation Analysis of New Perphosphorylated Calix[4]resorcinarenes
Authors: Maslennikova Vera I. , Serkova Olga S. , Gruner Marget , Goutal Sigrid , Bauer Ingmar , Habicher Wolf D. , Lyssenko Konstantin A. , Antipin Mikhail Yu. , Nifantyev Eduard E.
Published: November 2004

The octaphosphorylation of calix[4]resorcinarenes 1 by 2‐dialkylamino‐1,3,2‐diheterophosphorinanes 2 is described, and the effect of different factors on the structures of the resulting perphosphorylated products 3−5 was studied. Conformation analysis of these compounds by correlated 2D NMR spectroscopy and X‐ray diffraction analysis was performed, and it was found that compounds 3−5, like the initial resorcinarenes 1, each have the all‐cis configuration of the R groups in the methylidene bridges of the calixarene system, but different orientations of benzene rings and phosphorinane fragments with respect to one another and to the macrocycle plane. Perphosphorylated resorcinarenes 3a−c, 4a and 5a with R = alkyl exist in flattened cone conformations with the phosphorinane fragments on the same side of the macrocycle plane. The conformations of the perphosphorylated resorcinarenes 3d, 4b and 5b with R = Ph change to forms intermediate between flattened cone and 1,3‐alternate. The phosphorus fragments in these compounds are located on opposite sides of the macrocycle plane. It was shown that the oxidation and sulfurisation of phosphocalixarenes 3 proceed without any change in the spatial organisation of the macrocyclic system. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Reductive and Oxidative Transformations of the N‐(Cyanomethyl)oxazolidine System to Expand the Chiral Pool of Piperidines
Authors: François David , Poupon Erwan , Kunesch Nicole , Husson Henri‐Philippe
Published: November 2004

Two new reactions have been exploited to modify piperidine scaffolds containing the chiral, non‐racemic N‐(cyanomethyl)oxazolidine system. A Raney nickel mediated decyanation was studied first, followed by an oxidative process using potassium permanganate to furnish enantiopure lactams including oxopipecolic acid derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Novel Asymmetric Wittig Reaction: Synthesis of Chiral Allenic Esters
Authors: Pinho e Melo Teresa M. V. D. , Cardoso Ana L. , d’A. Rocha Gonsalves António M. , Costa Pessoa João , Paixão José A. , Beja Ana M.
Published: November 2004

Wittig reactions between 10‐(phenylsulfonyl)isobornyl (triphenylphosphoranylidene)acetates (1 and 6) and ketenes resulted in asymmetric induction, with the selective synthesis of allenes with axial chirality. Use of the (1R)‐(−)‐10‐(phenylsulfonyl)isoborneol unit allows the synthesis of allenes with S configuration, whereas use of the (1S)‐(+)‐10‐(phenylsulfonyl)isoborneol unit produces allenes with R configuration. The structure of (1R)‐(−)‐10‐(phenylsulfonyl)isobornyl (S)‐5,5‐dimethylhexa‐2,3‐dienoate (2e) was determined by X‐ray crystallography. Chirooptical studies of the allenic esters were carried out, confirming that two sets of enantiomeric derivatives were obtained. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Pyrano[2,3‐b]dioxanes through Bisacetalic Annulation of 2‐Ketosugars to Glycol
Authors: Cuny Eckehard , Lichtenthaler Frieder W. , Lindner Hans J.
Published: November 2004

The utility of 2‐ketohexosyl (“ulosyl”) bromides has been extended to the straightforward generation of cis‐fused pyrano[2,3‐b]dioxanes (1,4,5‐trioxadecalins) of type 11 and 13 by β‐specific and α‐selective glycosidation with glycol, and subsequent intramolecular hemiketalization. Mild basic conditions elicit highly stereoselective rearrangements to trioxadecalinones 22−25, representing the structurally and configurationally correct framework of steroidal natural products in which the sugar portion is doubly glycosidically linked to the aglycon. Exposure of 11 or 13 to mineral acid results in an essentially stereospecific contraction of the pyranoid ring to yield trioxaspiro[4,5]decanes. Mechanistic considerations of the unusual rearrangements observed are discussed in light of available experimental facts and the scarce existing analogies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
2‐Alkyl‐1,2,3,4‐benzotetrazinium Tetrafluoroborates: Their Reaction with Nucleophiles
Authors: Lipilin Dmitry L. , Smirnov Oleg Y. , Churakov Aleksandr M. , Strelenko Yuri A. , Tyurin Aleksei Y. , Ioffe Sema L. , Tartakovsky Vladimir A.
Published: November 2004

Treatment of 2‐alkyl‐1,2,3,4‐benzotetrazinium tetrafluoroborates with a nucleophile (AlkO−, ArO−, AcO−, Hal−, CN−, NCO−, ArNH2, AlkNH2, Alk2NH), at room temperature, results in elimination of an N2 molecule to afford ortho‐substituted azobenzenes. This reaction could be suitable for mild phenylation of carboxylic acids and other compounds containing active hydrogen. A plausible reaction pathway for the reaction is discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Bias correction for histogram estimator using line transect sampling
Authors: Eidous Omar M.
Published: November 2004

This article proposes a simple approach for reducing the bias of the traditional histogram estimator using line transect sampling. The approach uses the bias correction technique, which produces a new estimator for density of objects D. The proposed estimator reduces the bias from O(h2) to O(h3) as h → 0 under the shoulder condition assumption. The asymptotic properties of the proposed estimator are derived under some mild assumptions, and the optimal formula for the bin width is given. Small‐sample properties of the proposed estimator are studied and compared with some other existence estimators by using a simulation technique. The results show that improvements over the traditional histogram estimator often can be realized even at small or moderate sample size. Copyright © 2004 John Wiley & Sons, Ltd.
Humoral and contact interactions in astroglia/stem cell co‐cultures in the course of glia‐induced neurogenesis
Authors: Környei Zsuzsanna , Szlávik Vanda , Szabó Bálint , Gócza Elen , Czirók András , Madarász Emília
Published: November 2004

Astroglial cells support or restrict the migration and differentiation of neural stem cells depending on the developmental stage of the progenitors and the physiological state of the astrocytes. In the present study, we show that astroglial cells instruct noncommitted, immortalized neuroectodermal stem cells to adopt a neuronal fate, while they fail to induce neuronal differentiation of embryonic stem cells under similar culture conditions. Astrocytes induce neuron formation by neuroectodermal progenitors both through direct cell‐to‐cell contacts and via short‐range acting humoral factors. Neuron formation takes place inside compact stem cell assemblies formed 30– 60 h after the onset of glial induction. Statistical analyses of time‐lapse microscopic recordings show that direct contacts with astrocytes hinder the migration of neuroectodermal progenitors, while astroglia‐derived humoral factors increase their motility. In non‐contact co‐cultures with astrocytes, altered adhesiveness prevents the separation of frequently colliding neural stem cells. By contrast, in contact co‐cultures with astrocytes, the restricted migration on glial surfaces keeps the cell progenies together, resulting in the formation of clonally proliferating stem cell aggregates. The data indicate that in vitro maintained parenchymal astrocytes (1) secrete factors, which initiate neuronal differentiation of neuroectodermal stem cells; and (2) provide a cellular microenvironment where stem cell/stem cell interactions can develop and the sorting out of the future neurons can proceed. In contrast to noncommitted progenitors, postmitotic neuronal precursors leave the stem cell clusters, indicating that astroglial cells selectively support the migration of maturing neurons as well as the elongation of neurites. © 2004 Wiley‐Liss, Inc.
Lipopolysaccharide affects Golli expression and promotes proliferation of oligodendrocyte progenitors
Authors: Filipovic Radmila , Zecevic Nada
Published: November 2004

Proliferation of oligodendrocyte progenitor cells (OPCs) is important for initial myelination as well as for remyelination in demyelinating diseases. Previously, we showed that numerous OPCs and activated microglia, are present around multiple sclerosis lesions, and that they accumulate Golli proteins. Golli proteins, present in both neuronal and immune cells, might have a role in the immune processes, as well as in development of neurons and oligodendrocytes. We hypothesize that Golli proteins, generated by microglia in response to inflammation, promote proliferation of OPCs. To test this hypothesis, we induced inflammation in neonatal mouse brain slice culture with bacterial endotoxin lipopolysaccharide (LPS). Treated slices showed an increase in the number of OPCs. Several results support the notion that this effect of LPS is conveyed through activation of microglia and upregulation of Golli proteins. First, LPS‐treated brain slices have increased expression of Golli proteins observed by immunofluorescence and Western blot analysis. Second, Golli proteins were demonstrated only in the conditioned medium from LPS‐treated microglial cell cultures (LPS‐MCM), and were absent in either the conditioned media from LPS‐treated astrocytes or the control media. Third, proliferation of purified OPCs was promoted with LPS‐MCM or Golli proteins, but not with LPS alone. Taken together, these results demonstrate that microglia and/or microglia secreted factors, are necessary for the LPS‐promoted proliferation of OPCs and suggest possible involvement of Golli proteins as one of mediators in this process. © 2004 Wiley‐Liss, Inc.
In vivo efficacy of HSV‐TK transcriptionally targeted to the tumour vasculature is augmented by combination with cytotoxic chemotherapy
Authors: Mavria Georgia , Harrington Kevin J. , Marshall Christopher J. , Porter Colin D.
Published: November 2004

Background

Retroviral vectors are suitable for targeting endothelial cells in the tumour neovasculature because of their intrinsic selectivity for proliferating cells. Previously, we inserted regulatory elements of the endothelial‐specific prepro‐endothelin‐1 (ppET1) promoter in retroviral vectors to generate high‐titre, replication‐defective recombinant retroviruses that restricted gene expression to the vascular compartment of tumours.

Methods

A retroviral vector was generated in which expression of herpes simplex virus thymidine kinase (HSV‐TK) was transcriptionally restricted to endothelial cells, under the control of a hybrid ppET‐1 LTR. Xenograft tumour models were used to determine the efficacy of targeting HSV‐TK to the tumour vasculature. Subsequently, vascular‐targeted gene therapy was combined with chemotherapeutic agents.

Results

Breast or colorectal xenograft tumour growth was reduced and survival was increased in response to ganciclovir treatment. Treatment resulted in widespread vascular disruption and tumour cell apoptosis. In colorectal tumours, combination with irinotecan, a cytotoxic drug used to treat colorectal cancer, significantly increased survival compared to drug alone. No beneficial effect on survival was observed when combined with cisplatin, a cytotoxic drug not in clinical use for this tumour type. On the basis of their relative efficacies in vitro against tumour and endothelial cells, co‐operativity with irinotecan likely derives from additionally targeting the peripheral tumour cells that survive the anti‐vascular treatment.

Conclusions

We show that the ppET1‐targeted vector is efficacious for therapeutic gene expression in vivo, validating a strategy targeted to tumour vasculature, and demonstrate that vascular targeting combined with appropriate chemotherapy is more effective than either therapy alone. Copyright © 2004 John Wiley & Sons, Ltd.
Spatial distribution of some dynamic parameters during the evolution of selected depressions over the area of Cyprus
Authors: Nicolaides Kleanthis , Michaelides Silas , Karacostas Theodore
Published: November 2004

During the cold season, the cyclonic systems that reach the eastern Mediterranean from the surrounding geographical region and those that are formed over the area are largely associated with unsettled weather conditions over the island of Cyprus. For a better understanding of the evolution of these synoptic‐scale systems, some of the dynamic characteristics of selected groups of baroclinic depressions that affected the area during the winter season were studied. More specifically, the spatial isobaric distribution of the fields of relative vorticity, divergence, vertical motion and a static stability parameter were considered in relation to the evolution of each grouping of such depressions. The study focuses on 150 depressions in the colder months of November to March, from the beginning of January 1988 till the end of December 1996. Five groups of depressions were established and studied separately: those originating from north, east, south and west and those that form in situ. The time of maximum deepening of each depression was determined from the surface synoptic analyses and the spatial distributions of the above parameters were established for this time, 1 day before and 1 day after. The data used are the 2.5° × 2.5° standard‐level isobaric analyses compiled by the National Centers for Environmental Prediction–National Center for Atmospheric Research. The results presented in this study refer only to three tropospheric isobaric levels, namely 850, 500 and 300 hPa. Copyright © 2004 Royal Meteorological Society
Heating degree‐days over Greece as an index of energy consumption
Authors: Matzarakis Andreas , Balafoutis Christos
Published: November 2004

The geographical distribution of heating degree‐days (HDDs) in Greece is studied by means of special maps. HDDs are calculated by using daily thermal parameters (daily maximum and minimum air temperature) and then compared with an experimentally determined basic air temperature equal to 14 °C, according to our estimations. These calculations are based on daily weather data of 40 meteorological stations of the Hellenic National Weather Service published in the Monthly Climatic Bulletin.

The regionalization of the 40‐point stations' data was achieved using the multiple regression analysis technique and a digital terrain model. For the statistical analysis, the calculated HDDs provide the dependent variables, and geographical data of latitude and longitude, elevation, nearest grid distance from the sea and the land/sea ratio were the independent variables. The resultant statistical correlation was very high.

The final outcome of this study was the drawing up of 10 HDD maps, eight for the eight coldest months (October to May) in Greece, one for the entire cold period and one for the number of days demanding heating. The geographical distribution of HDDs is consistent with the great variety of Greek climates arising from the influence of the country's variable relief.

The distribution of the HDDs presented in the maps shows that the calculated values were close to the measured ones, which confirms the accuracy of the statistical model used. Possible small deviations were deemed to be acceptable, as the net of the stations used is sparse and it is limited to the elevations below 700 m above sea level. The high accuracy of the HDD maps will be useful for various energy projects and other environmental applications. Copyright © 2004 Royal Meteorological Society
On the response of the Aegean Sea to climatic variability: a review
Authors: Zervakis V. , Georgopoulos D. , Karageorgis A. P. , Theocharis A.
Published: November 2004

The Aegean Sea is a region of special interest for the Mediterranean oceanographic community, as one of the dense‐water formation sites of the Mediterranean, driving its thermohaline circulation. Early oceanographic literature exhibits significantly varying opinions regarding the role of the Aegean as a contributor to the water masses of the eastern Mediterranean. The higher temporal and spatial resolution studies that followed the introduction of Conductivity‐Temperature‐Depth (CTD) profilers in the 1980s, revealed that the various scenarios were within the interannual variability of dense water formation in the region. A peak in this variability was the appearance of the Eastern Mediterranean Transient event in the early 1990s. This phenomenon showed that the Aegean Sea has the potential to function as a source of dense water for the eastern Mediterranean; however, it takes over this role only sporadically, depending on the meteorological conditions over the eastern Mediterranean and, possibly, central/eastern Europe. The North Atlantic oscillation appears to be a contributor to this bimodal behaviour. Palaeoceanographic information has confirmed the large sensitivity of the Aegean Sea to climatic variability. Based on the available information, possible scenarios are examined for the response of the Aegean to the current climatic trends. Copyright © 2004 Royal Meteorological Society
Relation between sensible and latent heat fluxes in the Mediterranean and precipitation in the Greek area during winter
Authors: Lolis C. J. , Bartzokas A. , Katsoulis B. D.
Published: November 2004

The variability of sensible and latent heat fluxes in the Mediterranean Sea and their effect on precipitation in the Greek area during the winter months are investigated for the 39 year period 1959–97 by using multivariate statistical methods. First, factor analysis is applied, mainly as a data reduction tool, and then canonical correlation analysis is applied on the factor scores time series of the two pairs, i.e. sensible heat flux–precipitation and latent heat flux–precipitation, to reveal their interrelations. The results show there is a statistically significant relationship between sensible and latent heat fluxes over the western Mediterranean Sea and precipitation in the western windward areas of Greece. The sensible and latent heat fluxes in the western Mediterranean Sea contribute significantly to depression development. The depressions formed advect cold and dry air masses over the western Mediterranean, reinforcing these sensible and latent heat fluxes. Furthermore, these depressions lead to a southerly or southwesterly airflow over Greece. This flow, along with the existence of potential instability, significantly contributes to precipitation formation in the windward areas of western Greece and also in the islands of the eastern Aegean Sea. Copyright © 2004 Royal Meteorological Society
Polymerization of 1,3‐Pentadiene Initiated by Aluminium Trichloride in Nonpolar Solvent: Pseudo‐Control is Explained by Continuous Grafting
Authors: Delfour Marilyn , Bennevault‐Celton Véronique , Nguyen Hung Anh , Cheradame Hervé , Macedo Anne
Published: November 2004

Summary: The cationic polymerization of 1,3‐pentadiene initiated by AlCl3 was studied in nonpolar solvent. It was previously shown that at room temperature the active species were long‐lived and that the number‐average molar mass of the polymer chains was increasing with the polymerization yield. In order to explain this apparent control, the macromolecules were labeled with a transfer agent, triphenylamine (NPh3). The latter binds to active species by electrophilic aromatic substitution. The labeling of the polymer chains indicated that at 20 °C the polymer chains mainly contained one NPh3 molecule per macromolecule while the NPh3 content was higher for the high molar mass chains due to a “grafting from” polymer transfer mechanism. Thus, the pseudo‐control was assigned to the branching reactions. The labeling process by NPh3 also succeeded at −10 °C. Whereas at −10 °C a dialkylation of NPh3 was observed, a trialkylation at 20 °C was obtained. The analysis of the polymer microstructure at both temperatures highlighted an interaction between the active centers and NPh3. This paper also describes a process to synthesize tri‐arm stars polymers by cationic polymerization.

RI SEC chromatograms of soluble polymers synthesized at 20 °C in the presence of NPh3 with increasing reaction times (r = [NPh3]/[AlCl3] = 1); (a) t = 0.25 h, (b) t = 0.5 h, (c) t = 1 h, (d) t = 2 h, (e) t = 18 h, (f) t = 48 h; [AlCl3] = 2.3 × 10−2 mol · L−1, [1,3‐pentadiene] = 1.6 mol · L−1, pentane.

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RI SEC chromatograms of soluble polymers synthesized at 20 °C in the presence of NPh3 with increasing reaction times (r = [NPh3]/[AlCl3] = 1); (a) t = 0.25 h, (b) t = 0.5 h, (c) t = 1 h, (d) t = 2 h, (e) t = 18 h, (f) t = 48 h; [AlCl3] = 2.3 × 10−2 mol · L−1, [1,3‐pentadiene] = 1.6 mol · L−1, pentane.
UV Laser Chemical Vapor Deposition of Nano‐Chained Copolymer from Carbon Disulfide and Ethene
Authors: Tomovska Radmila , Bastl Zdeněk , Pola Josef
Published: November 2004

Summary: Laser irradiation at 193 nm of gaseous mixtures of carbon disulfide and ethene induces copolymerization of both compounds and affords chemical vapor deposition of conjugated nano‐chained C/S/H polymer, with contributions from C2H4 and CS2 almost unaffected by very different initial ratio of both educts. The polymer structure is interpreted on the basis of X‐ray photoelectron and FTIR spectra as consisting of >CS, >CC<, CH2CH2, (CC)SnC4−n, C(CS)S, S(CS)S and CSSC configurations, whose extent is dependent on the irradiation conditions.

Typical TEM image of the solid copolymer obtained by laser‐induced copolymerization of carbon disulfide and ethene.

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Typical TEM image of the solid copolymer obtained by laser‐induced copolymerization of carbon disulfide and ethene.
Liquid‐Crystalline Colloidal Particles
Authors: Vennes Melanie , Zentel Rudolf
Published: November 2004

Summary: Here we report about the synthesis of colloidal particles of nematic and smectic liquid‐crystalline polymers. For this purpose mesogen‐containing acrylate monomers were synthesized and polymerized in a special modification of a precipitation polymerization called dispersion polymerization. By variation of the polymerization conditions colloidal particles of different size and polydispersity could be obtained including very narrowly distributed samples in optimized batches. On azobenzene‐containing colloidal particles switching experiments with polarized light were performed. It could be observed that the nematic director of the mesogens within the colloidal particles can be rotated due to the photochemical trans‐cis‐isomerization of the azobenzene chromophores.

Microscope images of a monolayer of P3‐9.

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Microscope images of a monolayer of P3‐9.
A general advancing front technique for filling space with arbitrary objects
Authors: Löhner Rainald , Oñate Eugenio
Published: November 2004

An advancing front space‐filling technique for arbitrary objects has been developed. The input required consists of the specification of the desired mean point distance in space and an initial triangulation of the surface. One object at a time is removed from the active front, and, if possible, surrounded by admissible new objects. This operation is repeated until no active objects are left. Two techniques to obtain maximum packing are discussed: closest object placement (during generation) and move/enlarge (after generation). Different deposition or layering patterns can be achieved by selecting the order in which objects are eliminated from the active front. Timings show that for simple objects like spheres the scheme is considerably faster than volume mesh generators based on the advancing front technique, making it possible to generate large (> 106) yet optimal clouds of points in a matter of minutes on a PC. For more general objects, the performance may degrade depending on the complexity of the penetration checks. Several examples are included that demonstrate the capabilities of the technique. Copyright © 2004 John Wiley & Sons, Ltd.
Continuous design transmutation method for problems in engineering analysis
Authors: Mu Zongliang , Kazerounian Kazem
Published: November 2004

Many problems in engineering analysis and design involve searching solutions of a system of equations. In most cases, because these equations are highly coupled and non‐linear and thus unlikely to yield close‐form solutions, researchers seek possible solutions using numerical techniques. In this paper, we present a ‘Continuous Design Transmutation Method’, a numerical method based on the polynomial continuation theory that has been discussed in recent works appearing in engineering literature. Our model departs from similar approaches in that its start system and homotopy are based on physical design and not pure mathematical equations. To avoid singularity on real paths, we introduce a heuristic disturbance mechanism. First, we simplify target design in order to construct a design that possesses both a similar structure and known solutions. Then, we construct a homotopy between the governing equations of the simplified design and those of the target design. The solutions of the target problem emerge as one tracks the solutions of the simplified design's governing equations as these incrementally evolve from the simplified design into the target design. Using our method, one tracks only isolated solutions of the simplified problem. All of the extraneous paths have been eliminated before the solution‐tracking procedure begins. As a result, not only can one easily interpret, in physical terms, the transmutation process, but one can also monitor the design feature changes. In this paper, we demonstrate our method as applied to two sample problems: a five‐point position‐generation problem for a planar four‐bar mechanism and a function‐generation problem for an RSSR linkage. Copyright © 2004 John Wiley & Sons, Ltd.
Construction of polygonal interpolants: a maximum entropy approach
Authors: Sukumar N.
Published: November 2004

In this paper, we establish a link between maximizing (information‐theoretic) entropy and the construction of polygonal interpolants. The determination of shape functions on n‐gons (n>3) leads to a non‐unique under‐determined system of linear equations. The barycentric co‐ordinates ϕi, which form a partition of unity, are associated with discrete probability measures, and the linear reproducing conditions are the counterpart of the expectations of a linear function. The ϕi are computed by maximizing the uncertainty H(ϕ1,ϕ2,…,ϕn)=−∑ ϕi logϕi, subject to the above constraints. The description is expository in nature, and the numerical results via the maximum entropy (MAXENT) formulation are compared to those obtained from a few distinct polygonal interpolants. The maximum entropy formulation leads to a feasible solution for ϕi in any convex or non‐convex polygon. This study is an instance of the application of the maximum entropy principle, wherein least‐biased inference is made on the basis of incomplete information. Copyright © 2004 John Wiley & Sons, Ltd.