bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Halogenochalcogeno(IV) Acids: [H3O(Benzo‐18‐crown‐6)]2 [Te2Br10] and [H5O2(Dibenzo‐24‐crown‐8)]2 [Te2Br10].
Authors: Hammerschmidt A. , Bonmann S. , Laege M. , Krebs B. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Syntheses, Structure, Some Band Gaps, and Electronic Structures of CsLnZnTe3 (Ln: La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Y).
Authors: Yao Jiyong , Deng Bin , Sherry Leif J. , McFarland Adam D. , Ellis Donald E. , Van Duyne Richard P. , Ibers James A. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Oxygen‐Promoted Palladium(II) Catalysis: Facile C(sp2)—C(sp2) Bond Formation via Cross‐Coupling of Alkenylboronic Compounds and Olefins.
Authors: Yoon Cheol Hwan , Yoo Kyung Soo , Yi Sung Wook , Mishra Rajesh K. , Jung Kyung Woon 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 2‐Alkylidenethiazolidine‐4,5‐diones and 2‐Alkylideneoxazolidine‐4,5‐diones by One‐Pot Cyclization of Arylacetonitriles with Heterocumulenes and Ethyl 2‐Chloro‐2‐oxoacetate.
Authors: Albrecht Uwe , Langer Peter 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Facile Regioselective Ring Opening of Aziridines to Haloamines Using Tetrabutylammonium Halides in the Presence of β‐Cyclodextrin in Water.
Authors: Narender M. , Surendra K. , Krishnaveni N. Srilakshmi , Reddy M. Somi , Rao K. Rama 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Enamination of β‐Dicarbonyl Compounds Catalyzed by CeCl3×7H2O at Ambient Conditions: Ionic Liquid and Solvent‐Free Media.
Authors: Khodaei Mohammad Mehdi , Khosropour Ahmad Reza , Kookhazadeh Mehdi 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Efficient Conversion of Tetrahydropyranyl (THP) Ethers to Their Corresponding Cyanides with Triphenylphosphine/2,3‐Dichloro‐5,6‐dicyanobenzoquinone/n‐Bu4 NCN.
Authors: Akhlaghinia Batool 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Efficient Oxidation of Cycloalkanols by Sodium Nitrite with Molecular Oxygen in Trifluoroacetic Acid.
Authors: Matsumura Yoshihiro , Yamamoto Yutaka , Moriyama Noriaki , Furukubo Shigeru , Iwasaki Fumiaki , Onomura Osamu 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Conversion of 3‐O‐Substituted 1,2‐Dibromoalkanes into 2‐Bromo‐1‐alkenes by the Selective Elimination: Its Application to Total Synthesis of 12‐Oxygenated Tremetones.
Authors: Ohgiya Tadaaki , Nishiyama Shigeru 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
One‐Flask Synthesis of Mono‐ and Trifunctionalized 21‐Thia and 21‐Oxaporphyrin Building Blocks and Their Application in the Synthesis of Covalent and Noncovalent Unsymmetrical Porphyrin Arrays.
Authors: Gupta Iti , Ravikanth Mangalampalli 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Highly Diastereoselective Arylation of (S)‐Mandelic Acid Enolate: Enantioselective Synthesis of Substituted (R)‐3‐Hydroxy‐3‐phenyloxindoles and (R)‐Benzylic Acids and Synthesis of Nitrobenzophenones.
Authors: Barroso Santiago , Blay Gonzalo , Cardona Luz , Fernandez Isabel , Garcia Begona , Pedro Jose R. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Copper Carbenoid Mediated N‐Alkylation of Imidazoles and Its Use in a Novel Synthesis of Bifonazole.
Authors: Cuevas‐Yanez Erick , Serrano Juan Manuel , Huerta Gloria , Muchowski Joseph M. , Cruz‐Almanza Raymundo 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
1,3‐Dipolar Cycloaddition of Dipolar Reagents to Bischalcones in the Presence of Chloramine‐T.
Authors: Padmavathi V. , Reddy K. Venugopal , Sarma M. Rajagopala , Sumathi R. P. , Reddy D. Bhaskar 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Challenging Synthesis of New 1,3,4‐Thiadiazole Derivatives Starting from 2‐Acylamino‐3,3‐dichloroacrylonitriles.
Authors: Golovchenko Oleksandr V. , Pilyo Stepan G. , Brovarets Vladimir S. , Chernega Alexander N. , Drach Boris S. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Efficient Enantioselective Synthesis of Functionalized Tetrahydropyrans by Ru‐Catalyzed Asymmetric Ring‐Opening Metathesis/Cross‐Metathesis (AROM/CM).
Authors: Gillingham Dennis G. , Kataoka Osamu , Garber Steven B. , Hoveyda Amir H. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Diastereo‐ and Enantioselective Synthesis of Bicyclic α‐Methylene‐δ‐valerolactones by Asymmetric Michael Reaction.
Authors: Krawczyk Henryk , Sliwinski Marcin , Wolf Wojciech M. , Bodalski Ryszard 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
New Entries in Lewis Acid—Lewis Base Bifunctional Asymmetric Catalyst: Catalytic Enantioselective Reissert Reaction of Pyridine Derivatives.
Authors: Ichikawa Eiko , Suzuki Masato , Yabu Kazuo , Albert Matthias , Kanai Motomu , Shibasaki Masakatsu 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Some 3‐Phenyl‐4‐methyl‐6‐(6‐arylpyridin‐2‐yl)‐ and 3‐Phenyl‐4‐methyl‐6‐(4,6‐diarylpyridin‐2‐yl) Coumarins.
Authors: Brahmbhatt D. I. , Patel C. N. , Pandya V. P. , Patel M. A. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Microwave Assisted Synthesis of 2‐(4‐Substituted piperazin‐1‐yl)‐1,8‐naphthyridine‐3‐carbonitrile as a New Class of Serotonin 5‐HT3 Receptor Antagonists.
Authors: Mahesh Radhakrishnan , Perumal Ramachandran Venkatesha , Pandi Pandi Vijaya 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 1‐Alkyl‐6‐aryl‐3‐n‐propyl‐5‐thioxo/oxo‐4,5,6,7‐tetrahydro‐1H‐pyrazolo [4,3‐d]pyrimidin‐7‐ones.
Authors: Reddy N. Ram , Reddy P. Pratap 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Activated Nitriles in Heterocyclic Chemistry: Facile Synthesis and Antimicrobial Activity of Some Pyrimidine, Pyrazolopyrimidine and Pyrazolotriazine Derivatives Containing Sulfonamido Moiety.
Authors: Ammar Y. A. , Saleh N. M. , Micky J. A. , Abbas H. A. S. , El‐Gaby M. S. A. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and AMPA Receptor Antagonistic Activity of a Novel 7‐Imidazolyl‐6‐trifluoromethyl Quinoxalinecarboxylic Acid with a Substituted Phenyl Group and Improved Its Good Physicochemical Properties by Introduced CF3 Group.
Authors: Takano Yasuo , Shiga Futoshi , Asano Jun , Hori Wataru , Anraku Tsuyosi , Uno Takashi 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Hetarynic Synthesis and Chemical Transformations of Dihydrodiquinolinopyrazines.
Authors: Grig‐Alexa Irina‐Claudia , Garnier Ethel , Finaru Adriana‐Luminita , Ivan Lucia , Jarry Christian , Leger Jean‐Michel , Caubere Paul , Guillaumet Gerald 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis, Antimicrobial and Analgesic Activity of 4‐Aryl‐2‐N‐morpholino‐4‐oxo‐2‐butenoic Acids.
Authors: Koz'minykh V. O. , Belyaev A. O. , Koz'minykh E. N. , Makhmudov R. R. , Odegova T. F. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Stereoselective Hydroboration of Diynes and Triyne to Give Products Containing Multiple Vinylene Bridges: A Versatile Application to Fluorescent Dyes and Light‐Emitting Copolymers.
Authors: Lee Taegweon , Baik Chul , Jung Il , Song Kyu Ho , Kim Sanghoon , Kim Duckhyun , Kang Sang Ook , Ko Jaejung 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
The Reaction of Butatrienolates with Aldehydes for the Syntheses of α‐Vinylidene Acylsilanes.
Authors: Shibata Takanori , Takami Kyoko , Arai Yoshikazu , Tsuchikama Kyoji , Maekawa Shunsuke 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Design, Syntheis, and Evaluation of Oxyanion‐Hole Selective Inhibitor Substituents for the S1 Subsite of Factor Xa.
Authors: Rumthao Sochanchingwung , Lee Oukseub , Sheng Qi , Fu WenTao , Mulhearn Debbie C. , Crich David , Mesecar Andrew D. , Johnson Michael E. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Some New 1,2,3‐Selenadiazolo[4′,5′:5,4]cyclopent[b]indoles (III) and 6,11‐Dihydro‐5‐methylquinolino[2′,3′:5,4]cyclopent[b]indoles (VI)
Authors: Sangeetha V. , Prasad K. J. Rajendra 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Thiostannylation of Arynes with Stannyl Sulfides: Synthesis and Reaction of 2‐(Arylthio)arylstannanes.
Authors: Yoshida Hiroto , Terayama Tsuguaki , Ohshita Joji , Kunai Atsutaka 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
New Minor Ecdysteroids from Silene viridiflora.
Authors: Mamadalieva Nilufar Z. , Zibareva Larisa N. , Evrard‐Todeschi Nathalie , Girault Jean‐Pierre , Maria Annick , Ramazanov Nurmurod Sh. , Saatov Ziyadilla , Lafont Rene 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Homologation of α‐Amino Acids to β‐Amino Acids: 9‐Fluorenylmethyl Chloroformate as a Carboxyl Group Activating Agent for the Synthesis of Nα‐Protected Aminoacyldiazomethanes.
Authors: Kantharaju Kantharaju , Babu Vommina V. Suresh 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Looking Glass Inhibitors: L‐DMDP, a More Potent and Specific Inhibitor of α‐Glucosidases than the Enantiomeric Natural Product DMDP.
Authors: Yu Chu‐Yi , Asano Naoki , Ikeda Kyoko , Wang Mei‐Xiang , Butters Terry D. , Wormald Mark R. , Dwek Raymond A. , Winters Ana L. , Nash Robert J. , Fleet George W. J. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Oligonucleosome DNA Fragmentation of Caspase 3 Deficient MCF‐7 Cells in Palmitate‐Induced Apoptosis
Authors: Semenov D. V. , Aronov P. A. , Kuligina E. V. , Potapenko M. O. , Richter V. A. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Investigation of Tumor‐Derived Extracellular DNA in Blood of Cancer Patients by Methylation‐Specific PCR
Authors: Rykova Elena Y. , Skvortsova Tatyana E. , Laktionov Pavel P. , Tamkovich Svetlana N. , Bryzgunova Olga E. , Starikov Andrey V. , Kuznetsova Nina P. , Kolomiets Sergei A. , Sevostianova Natalia V. , Vlassov Valentin V. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Extracellular Circulating Nucleic Acids in Human Plasma in Health and Disease
Authors: Laktionov Pavel P. , Tamkovich Svetlana N. , Rykova Elena Yu. , Bryzgunova Olga E. , Starikov Andrey V. , Kuznetsova Nina P. , Sumarokov Sergey V. , Kolomiets Sergey A. , Sevostianova Natalya V. , Vlassov Valentin V. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Photoanalogues of the Initiation Substrates of the RNA Polymerase II, 5‐Azido‐2‐nitrobenzoyl Derivatives of the ATP γ‐Amidophosphate: The Possible Photoinduced Degradation of the Functional Group to an N‐Arylhydroxylamine
Authors: Popova T. V. , Mal'shakova V. S. , Alekseyev P. V. , Kudryashova N. V. , Shakirov M. M. , Savinkova L. L. , Drachkova I. A. , Godovikova T. S. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Ternary Indides Ln10Rh9.+‐.xIn20 (Ln: Y, Tb—Tm, Lu) and YbRhIn2 — Syntheses and Crystal Chemical Peculiarities.
Authors: Lukachuk Mar'yana , Rodewald Ute Ch. , Zaremba Vasyl I. , Hoffmann Rolf‐Dieter , Poettgen Rainer 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
(Sr3N)E and (Ba3N)E (E: Sb, Bi): Synthesis, Crystal Structures, and Physical Properties.
Authors: Gaebler Frank , Kirchner Martin , Schnelle Walter , Schwarz Ulrich , Schmitt Miriam , Rosner Helge , Niewa Rainer 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
X‐Ray and Transmission Electron Microscopy Investigations of the New Solids In5S5Cl, In5Se5Cl, In5S5Br, and In5Se5Br.
Authors: Deiseroth Hans‐Joerg , Reiner Christof , Xhaxhiu Kledi , Schlosser Marc , Kienle Lorenz 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Syntheses and Crystal Structures of the Compounds In3.7Mo15S19, In1.6Rb2Mo15S19, In2.2CsMo15S19 and ScTl2Mo15S19 Containing Mo6 and Mo9 Clusters.
Authors: Salloum Diala , Gougeon Patrick , Roisnel Thierry , Potel Michel 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Chiral [2.2.2] Dienes as Ligands for Rh(I) in Conjugate Additions of Boronic Acids to a Wide Range of Acceptors.
Authors: Defieber Christian , Paquin Jean‐Francois , Serna Sonia , Carreira Erick M. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A New Class of Substituted Aryl Bis(oxazoline) Ligands for Highly Enantioselective Copper‐Catalyzed Asymmetric Aldol Addition of Dienolsilane to Pyruvate and Glyoxylate Esters.
Authors: Le Julie Cong‐Dung , Pagenkopf Brian L. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Preparation and Resolution of a Modular Class of Axially Chiral Quinazoline‐Containing Ligands and Their Application in Asymmetric Rhodium‐Catalyzed Olefin Hydroboration.
Authors: Connolly David J. , Lacey Patrick M. , McCarthy Mary , Saunders Cormac P. , Carroll Anne‐Marie , Goddard Richard , Guiry Patrick J. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Ru‐ and Rh‐Catalyzed C—C Bond Cleavage of Cyclobutenones: Reconstructive and Selective Synthesis of 2‐Pyranones, Cyclopentenes, and Cyclohexenones.
Authors: Kondo Teruyuki , Taguchi Yoshinori , Kaneko Yushi , Niimi Masatsugu , Mitsudo Take‐aki 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Preparation of an Aliphatic‐Substituted Hypervalent Iodine Compound, Tetracoordinate 1,2‐Iodoxetane 1‐Oxide, and Its Application to Oxidation.
Authors: Kano Naokazu , Ohashi Masaki , Hishiba Kazuhisa , Kawashima Takayuki 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Diastereoselective Synthesis of Cycloheptadienol Derivatives by a Formal [5 + 2] Carbocyclization Reaction of α,β,γ,δ‐Diunsaturated (Methoxy)carbene Complexes with Methyl Ketone Lithium Enolates.
Authors: Barluenga Jose , Alonso Jorge , Fananas Francisco J. , Borge Javier , Garcia‐Granda Santiago 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Selective para‐Iodination of Methoxyarenes, Phenols, and Anilines with Iodine in the Presence of Poly(4‐vinylpyridine)‐Supported Peroxodisulfate.
Authors: Tajik Hassan , Mohammadpoor‐Baltork Iraj , Rasht‐Abadi Hassan Rafiee 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
TMEDA‐Catalyzed Synthesis of N‐Aryl‐N′‐ethoxycarbonyl Thiourea and Arene (or Polymethylene)‐bis‐ethoxycarbonylthiourea Derivatives.
Authors: Lin Qi , Zhang You‐Ming , Gao Li‐Ming , Wei Tai‐Bao , Wang Hai 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Titanocene‐Catalyzed Coupling of Aromatic Amides in the Presence of Organosilanes: A Novel Route to Vicinal Diamines and a New Class of Amine‐Substituted Oligomers.
Authors: Rangareddy Kesamreddy , Selvakumar Kumaravel , Harrod John F. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Preparation of Room‐Temperature Ionic Liquids by Neutralization of 1,1,3,3‐Tetramethylguanidine with Acids and Their Use as Media for Mannich Reaction.
Authors: Gao Haixiang , Han Buxing , Li Junchun , Jiang Tao , Liu Zhimin , Wu Weize , Chang Yanhong , Zhang Jianmin 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Total Regioselective and Diastereospecific Iodolysis of 2,3‐Epoxyamides Promoted by SmI2: Synthesis of (2R*,3R*)‐ or (2R*,3S*)‐2‐Hydroxy‐3‐iodoamides.
Authors: Concellon Jose M. , Bardales Eva , Concellon Carmen , Garcia‐Granda Santiago , Diaz M. Rosario 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Notable Coordination Effects of 2‐Pyridinesulfonamides Leading to Efficient Aziridination and Selective Aziridine Ring Opening.
Authors: Han Hoon , Bae Imhyuck , Yoo Eun Jeong , Lee Junseong , Do Youngkyu , Chang Sukbok 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Structure—Reactivity Relationships in Oxidative Carbon—Carbon Bond Forming Reactions: A Mild and Efficient Approach to Stereoselective Syntheses of 2,6‐Disubstituted Tetrahydropyrones.
Authors: Wang Lijun , Seiders John R. II , Floreancig Paul E. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A 2:1 Coupling Reaction of Arynes with Aldehydes via o‐Quinone Methides: Straightforward Synthesis of 9‐Arylxanthenes.
Authors: Yoshida Hiroto , Watanabe Masahiko , Fukushima Hiroyuki , Ohshita Joji , Kunai Atsutaka 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Concise Synthesis of trans‐ and cis‐3,4‐Disubstituted Piperidines Based on Regio‐ and Stereoselective Allylation of Cyclopentenyl Esters.
Authors: Igarashi Junji , Ishiwata Hiroyuki , Kobayashi Yuichi 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Chiral Nonracemic 1‐(2‐Pyridinyl)ethylamines: Stereospecific Introduction of Amino Function onto the 2‐Pyridinylmethyl Carbon Center.
Authors: Uenishi Jun'ichi , Hamada Masahiro , Aburatani Sachiko , Matsui Katsuya , Yonemitsu Osamu , Tsukube Hiroshi 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Search for Histamine H3 Receptor Ligands with Combined Inhibitory Potency at Histamine N‐Methyltransferase: ω‐Piperidinoalkanamine Derivatives.
Authors: Grassmann Sven , Apelt Joachim , Ligneau Xavier , Pertz Heinz H. , Arrang Jean‐Michel , Ganellin C. Robin , Schwartz Jean‐Charles , Schunack Walter , Stark Holger 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Ru3(CO)12‐Catalyzed Silylation of Benzylic C—H Bonds in Arylpyridines and Arylpyrazoles with Hydrosilanes via C—H Bond Cleavage.
Authors: Kakiuchi Fumitoshi , Tsuchiya Kazuyuki , Matsumoto Mitsutaka , Mizushima Eiichiro , Chatani Naoto 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Binding Properties of the Conjugates of Oligo(2′‐O‐Methylribonucleotides) with Minor Groove Binders Targeted to Double Stranded DNA
Authors: Novopashina D. S. , Sinyakov A. N. , Ryabinin V. A. , Venyaminova A. G. , Perrouault L. , Brunet E. , Giovannangeli C. , Boutorine A. S. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Alkylation of 5‐ and 6‐Methylindolo[2,3‐b]quinoxalines: Revised Structures of the N,N′‐Dimethylated Salts
Authors: Helissey Philippe , Desbène‐Finck Stéphanie , Giorgi‐Renault Sylviane 
Published: January 2005

AbstractN,N′‐Dialkylation of indolo[2,3‐b]quinoxaline could theoretically furnish three isomers, that is, salts dialkylated at the 5,6‐, the 6,11‐, and the 5,11‐positions. By using the 2,3‐dimethylated derivatives as models, the regioisomeric salts were selectively synthesized either by alkylation of the tetracycle or by cyclization of 1‐methylisatin with N,4,5‐trimethylbenzene‐1,2‐diamine. The structure of the N,N′‐dimethyl salts were unambiguously determined by NMR correlation sequences (1H‐1H NOESY, 1H‐13C HMQC, and 1H‐13C HMBC). The results of these studies show that the previous findings from the dialkylation of indoloquinoxaline need revision. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Formation and Structure of Conjugated Salen‐Cross‐Linked Polymers and Their Application in Asymmetric Heterogeneous Catalysis
Authors: Nielsen Morten , Thomsen Anne H. , Jensen Torben R. , Jakobsen Hans J. , Skibsted Jørgen , Gothelf Kurt V. 
Published: January 2005

AbstractA new type of cross‐linked condensation polymer was obtained by the reaction of 1,3,5‐tris[(5‐tert‐butyl‐3‐formyl‐4‐hydroxyphenyl)ethynyl]benzene (1) with ethylenediamine. Solid‐state 13C{1H} CP/MAS NMR analysis showed that the polymer was pure and highly cross‐linked and powder synchrotron X‐ray diffraction indicated some degree of local structural order in the polymer. A chiral manganese−salen‐bridged polymer was obtained by the condensation of 1 with (1R,2R)‐1,2‐diphenyl‐1,2‐diaminoethane (3a) or (1R,2R)‐1,2‐diaminocyclohexane (3b) in the presence of Mn(OAc)2. These rigid chiral metal−salen polymers can catalyze the epoxidation of cis‐2‐methylstyrene with high conversion, diastereoselectivity and enantioselectivities of up to 67% ee. The polymeric catalyst can be reused several times without reduced activity or selectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Enantiopure and Racemic Chiral Nitronyl Nitroxide Free Radicals: Synthesis and Characterization
Authors: Hirel Catherine , Pécaut Jacques , Choua Sylvie , Turek Philippe , Amabilino David B. , Veciana Jaume , Rey Paul 
Published: January 2005

AbstractA synthetic route to a series of homochiral (and achiral) nitronyl nitroxides derived from rac‐(and meso)‐3,4‐dimethyl‐3,4‐dinitrohexane is described. The two forms of this precursor, meso and rac, were identified unambiguously and reduced to the corresponding meso‐ and rac‐diamines. The rac‐diamine was condensed with an enantiopure aldehyde specifically designed to give a diastereomeric mixture of imidazolidines easily separated by flash chromatography. Both enantiopure diamines were then obtained by acidic hydrolysis of these imidazolidines. The absolute configurations of the diamino precursors were determined by X‐ray crystallography of single crystals of a manganese(II) complex [(R,R,R)‐5E·Mn(hfac)2] of a nitroxide containing a third chiral center of known configuration. A series of homochiral nitronyl nitroxides was then prepared from the enantiopure diamino precursors by condensation with aldehydes, followed by oxidation. Their structural properties were compared to those of their achiral meso counterparts and it was found that the puckering of the five‐membered ring is dependent on the chirality of the imidazolyl unit. The radicals show marked optical activity, as explored by polarimetry and circular dichroism spectroscopy. These paramagnetic building blocks of known absolute configuration include chiral centers adjacent to the oxyl groups, and since they exhibit C2 symmetry they are well suited for coordination chemistry studies because stereochemical complexity is minimized. They have been specifically designed for further developments of the metal‐radical approach to molecular magnetic materials. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Palladium‐Catalyzed Arylation of Linear and Cyclic Polyamines
Authors: Beletskaya Irina P. , Bessmertnykh Alla G. , Averin Alexei D. , Denat Franck , Guilard Roger 
Published: January 2005

AbstractThe palladium‐catalyzed arylation of polyamines is investigated and it is shown that the C−N coupling reaction for a given substrate is strongly dependent on the nature and the concentration of the catalytic system, as well as the nature of the base employed. The arylation of the primary amino group is favored when both primary and secondary amines are present; selective arylation is then possible without using any protecting group. The reaction of dihalobenzenes with polyamines gives the monoamination products in good yields without any significant formation of diamino compounds or reduced derivatives, unlike what is observed when monoamines are used. The extent of polyarylation of polyamines as a function of the excess of aryl halide and the nature and the amount of catalyst is also studied. Finally, N‐arylation of a macrocyclic tetraamine (cyclam) is performed by using an appropriate catalytic system. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)