bluuebunny/crossref_metadata_2025 huggingface dataset:
MIMO Systems for Wireless Communications
Authors: Iyanda Sulyman Ahmed , Ibnkahla Mohamed
Published: April 2005

Demands for high‐speed, reliable wireless data communications have increased rapidly. Multiple input–multiple output (MIMO) communication systems have recently been embraced as an effective means to achieve high data rate transmission over wireless channels. Several MIMO signal processing techniques have thus been exploited, each of them aimed at providing high data rate while optimizing various other additional performance criteria. These techniques include spacetime codes, MIMO beamforming, and spatial multiplexing systems among others. In this article, an overview of these MIMO algorithms is presented. Performance improvement of the MIMO communications system over the conventional wireless communications system is then illustrated. Equalization techniques employed in MIMO receivers for transmissions over frequency‐selective channels are then reviewed.
Maxwellian Circuits
Authors: Mei Kenneth K.
Published: April 2005

A Maxwellian circuit is defined as a discretized equivalent circuit of a wire structure, the solution of which is the same as that of the Maxwell's equations satisfying the same boundary conditions of the circuit. The theory of Maxwellian circuits is based on the existence and uniqueness theorems of equivalent differential equations of each thin‐wire‐type integral equation, which is derived from Maxwell's equations. In this article, the proofs of the basic theorems are presented, calculations verifying the theory are shown in figures, and related applications are discussed.
A novel process configuration for anaerobic digestion of source‐sorted household waste using hyper‐thermophilic post‐treatment
Authors: Hartmann Hinrich , Ahring Birgitte K.
Published: April 2005

A novel reactor configuration was investigated for anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW). An anaerobic hyper‐thermophilic (68°C) reactor R68 was implemented as a post‐treatment step for the effluent of a thermophilic reactor R1 (55°C) in order to enhance hydrolysis of recalcitrant organic matter, improve sanitation and ease the stripping of ammonia from the reactor. The efficiency of the combined system was studied in terms of methane yield, volatile solids (VS) reduction, and volatile fatty acid (VFA) production at different hydraulic retention times (HRT). A single‐stage thermophilic (55°C) reactor R2 was used as control. VS reduction and biogas yield of the combined system was 78–89% and 640–790 mL/g VS, respectively. While the VS reduction in the combined system was up to 7% higher than in the single‐stage treatment, no increase in methane yield was observed. Shifting the HRT of the hyper‐thermophilic reactor from 5 days to 3 days resulted in a drop in the methanogenic activity in the hydrolysis reactor to a minimum. Operation of R68 at HRTs of 24–48 h was sufficient to achieve high VS conversion into VFAs. Removal of pathogens was enhanced by the hyper‐thermophilic post‐treatment. 7% of the ammonia load was removed in the hyper‐thermophilic reactor with a flow of headspace gas through the reactor equivalent to four times the biogas flow produced in reactor R1. © 2005 Wiley Periodicals, Inc.
Predicting New Ferromagnetic Nitrides from Electronic Structure Theory: IrFe3N and RhFe3N.
Authors: von Appen Joerg , Dronskowski Richard
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
The Co2Al9 Structure Type Revisited.
Authors: Bostroem Magnus , Rosner Helge , Prots Yurii , Burkhardt Ulrich , Grin Yuri
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Tetracyanoborate Salts M[B(CN)4] with M = Singly Charged Cations: Properties and Structures.
Authors: Kueppers Torsten , Bernhardt Eduard , Willner Helge , Rohm Henning W. , Koeckerling Martin
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Electrical Conductivities and Conduction Mechanisms of Perovskite‐Type Na1‐xKxMgF3 (x = 0, 0.1,1) and KZnF3.
Authors: Yoshiasa Akira , Sakamoto Daisuke , Okudera Hiroki , Sugahara Masahiko , Ota Ken'ich , Nakatsuka Akihiko
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Photochemistry of MCl(H2O)4, M: H, Li, Na Clusters: Finite‐Size Models of the Photodetachment of the Chloride Anion in Salt Solutions
Authors: Sobolewski Andrzej L. , Domcke Wolfgang
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Carbodiimides with Extended Structure by an Azide—Cyanide Route: Synthesis and Crystal Structure of M2Cl2NCN (M: Eu and Sr).
Authors: Liao Wuping , Dronskowski Richard
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Et2AlCl‐Promoted Asymmetric Phenylseleno Group Transfer Radical Cyclization Reactions of Unsaturated β‐Hydroxy Esters.
Authors: Yang Dan , Gao Qiang , Zheng Bao‐Fu , Zhu Nian‐Yong
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Liquid‐Phase Oxidation of Sulfides by an Aluminum (and Titanium) tert‐Butoxide—tert‐Butyl Hydroperoxide System.
Authors: Dodonov V. A. , Zaburdaeva E. A. , Stepovik L. P.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Oxidative Transformation of 1,3‐Dioxacycloalkanes Induced by Chlorine Dioxide.
Authors: Abdrakhmanova A. R. , Kabal'nova N. N. , Rol'nik L. Z. , Yagafarova G. G. , Shereshovets V. V.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Aerobic Oxidation of Primary Alcohols in the Presence of Activated Secondary Alcohols.
Authors: Egami Hiromichi , Shimizu Hideki , Katsuki Tsutomu
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Imidazolium Salts as Phase‐Transfer Catalysts for the Dialkylation and Cycloalkylation of Active Methylene Compounds.
Authors: Muthusamy Sengodagounder , Gnanaprakasam Boopathy
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Cross‐Metathesis of 1,3‐Dienes with Electron‐Deficient Olefins.
Authors: Dewi Purnama , Randl Stefan , Blechert Siegfried
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Esterification of Aldehydes and Alcohols with Pyridinium Hydrobromide Perbromide in Water.
Authors: Sayama Shinsei , Onami Tetsuo
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Enantioselective Copper‐Mediated Allylic Substitution with Grignard Reagents Employing a Chiral Reagent‐Directing Leaving Group.
Authors: Breit Bernhard , Breuninger Daniel
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Ring‐Opening of Lactones with Enolate Nucleophiles: A Simple Access to Functionalized β‐Ketoesters, β,δ‐Diketoesters and β‐Ketosulfoxides.
Authors: Lanners Steve , Khiri Naima , Solladie Guy , Hanquet Gilles
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Practical Asymmetric Approach to Medium‐Sized Carbocycles Based on the Combination of Two Ru‐Catalyzed Transformations and a Lewis Acid‐Induced Cyclization.
Authors: Lopez Fernando , Castedo Luis , Mascarenas Jose L.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of 1,3‐Enynes via Suzuki‐Type Reaction of Vinylic Tellurides and Potassium Alkynyltrifluoroborate Salts.
Authors: Stefani Helio A. , Cella Rodrigo , Doerr Felipe A. , Pereira Claudio M. P. , Zeni Gilson , Gomes Marlito Jr.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Stereoselective Synthesis of (E)‐β‐Arylvinyl Bromides by Microwave‐Induced Reaction of anti‐3‐Aryl‐2,3‐dibromopropanoic Acids Using an AgOAc—AcOH System.
Authors: Kuang Chunxiang , Senboku Hisanori , Tokuda Masao
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Scope and Limitations of Pd2(dba)3/P (i‐BuNCH2CH2)3N‐Catalyzed Buchwald—Hartwig Amination Reactions of Aryl Chlorides.
Authors: Urgaonkar Sameer , Verkade John G.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Palladium—Imidazole Derivatives as Highly Active Catalysts for Heck Reactions.
Authors: Reddy K. Rajender , Krishna G. Gopi
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
CsOH×H2O‐Promoted Synthesis of Aryl Sulfides via Direct Coupling of Aryl Halides and Thiols.
Authors: Varala Ravi , Ramu E. , Alam M. Mujahid , Adapa Srinivas R.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Transition‐Metal‐Catalyzed Benzylation of Arenes and Heteroarenes.
Authors: Mertins Kristin , Iovel Irina , Kischel Jette , Zapf Alexander , Beller Matthias
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Three‐Component Reactions of Polynitromethanes with Alkynes. The First Synthesis of gem‐Dinitroaziridines.
Authors: Budynina Ekaterina M. , Averina Elena B. , Ivanova Olga A. , Kuznetsova Tamara S. , Zefirov Nikolai S.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
TiCl4‐Promoted Multicomponent Reaction: A New Entry to Functionalized α‐Amino Acids.
Authors: Ghosh Arun K. , Xu Chun‐Xiao , Kulkarni Sarang S. , Wink Donald
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Iridium Complex‐Catalyzed Intramolecular Ene‐Type Reaction of 1,6‐Enynes Accelerated in Ionic Liquid.
Authors: Shibata Takanori , Yamasaki Mitsunori , Kadowaki Sho , Takagi Kentaro
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Regioselective Ring‐Opening/Cross‐Metathesis Reactions of Norbornene Derivatives with Electron‐Rich Olefins.
Authors: Liu Zhuqing , Rainier Jon D.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Sequential Homobimetallic Catalysis: An Unprecedented Tandem Pd(0)‐Catalyzed Deprotection — Pd(II)‐Catalyzed Heterocyclization Reaction Leading to Benzofurans.
Authors: Gabriele Bartolo , Mancuso Raffaella , Salerno Giuseppe , Veltri Lucia
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
A Novel Biomimetic Route to the 3‐Acyl‐5‐hydroxy‐3‐pyrrolin‐2‐one and 3‐Acyl‐3,4‐epoxy‐5‐hydroxypyrrolidin‐2‐one Ring Systems.
Authors: Snider Barry B. , Neubert Bobbianna J.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
A Convenient Synthesis of 2‐Cyano‐3‐Substituted Indoles.
Authors: Denison Sophie , Hilton Stephen T.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Structure Based Approach to the Design of Bicyclic‐1H‐isoindole‐1,3(2H)‐dione Based Androgen Receptor Antagonists.
Authors: Salvati Mark E. , et al. et al.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Novel, Mild and Chemoselective Dehydrogenation of 2‐Imidazolines with Trichloroisocyanuric Acid.
Authors: Mohammadpoor‐Baltork Iraj , Zolfigol Mohammad Ali , Abdollahi‐Alibeik Mohammad
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
An Efficient One‐Pot Synthesis of Aminobenzimidazoles.
Authors: Fouchard David M. D. , Tillekeratne L. M. Viranga , Hudson Richard A.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Novel Synthesis of Bicycles with Fused Pyrrole, Indole, Oxazole, and Imidazole Rings.
Authors: Katritzky Alan R. , Singh Sanjay K. , Bobrov Sergey
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Oxazoles Formation During O‐Alkylation of Isonitroso‐naphthols. X‐Ray Structure of [1,2]Naphthoquinone 1‐[O‐(4‐tert‐Butyl‐benzyl)‐oxime] and 2‐(4‐tert‐Butyl‐phenyl)naphth[1,2‐d]oxazole.
Authors: Astolfi Paola , Carloni Patricia , Castagna Riccardo , Greci Lucedio , Rizzoli Corrado , Stipa Pierluigi
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Structure of Some Imines Containing a Furoxan Ring Derived from Isosafrole.
Authors: Nguyen Huu Dinh Nguyen Huu Dinh , Ngo Thi Ly Ngo Thi Ly , Le Thi Than Van Le Thi Than Van
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
3‐Nitrochromene Derivatives as 2π Components in 1,3‐Dipolar Cycloadditions of Azomethine Ylides.
Authors: Nyerges Miklos , Viranyi Andrea , Marth Gabriella , Dancso Andras , Blasko Gabor , Toeke Laszlo
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Nucleophilic Aromatic Substitution of Methyl 3‐Nitropyridine‐4‐carboxylate.
Authors: Holt Jarle , Tjosaas Freddy , Bakke Jan M. , Fiksdahl Anne
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Novel 4,5‐Diazafluoren‐9‐one Derivatives and Theoretical Study of [3 + 2] Cycloaddition Reactions.
Authors: Danac Ramona , Constantinescu Mircea , Rotaru Alexandru , Ghirvu Constantin , Druta Ioan
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Stereochemistry of Addition of Disulfonium Dications to Alkenes.
Authors: Shevchenko N. E. , Nenajdenko V. G. , Muzalevskii V. M. , Balenkova E. S.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
2,4,6‐Trifluoropyrimidine. Reactions with Nitrogen Nucleophiles.
Authors: Delia Thomas J. , Anderson Dennis P. , Schomaker Jennifer M.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
The Identification and Optimization of a N‐Hydroxy Urea Series of Flap Endonuclease 1 Inhibitors.
Authors: Tumey L. Nathan , et al. et al.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Biological Activity of 3,4‐Dihydroquinazolines for Selective T‐Type Ca2+ Channel Blockers.
Authors: Rhim Hyewhon , Lee Yong Sup , Park Seong Jun , Chung Bong Young , Lee Jae Yeol
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Antimalarial Evaluation of New N1‐(7‐Chloro‐4‐quinolyl)‐1,4‐bis(3‐aminopropyl)piperazine Derivatives.
Authors: Ryckebusch Adina , Debreu‐Fontaine Marie‐Ange , Mouray Elisabeth , Grellier Philippe , Sergheraert Christian , Melnyk Patricia
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
One‐Pot Synthesis of Alkyl Indeno[1,2‐b]quinoxalin‐11‐ylideneacetates under Solvent‐Free Conditions.
Authors: Azizian Javad , Mohammadizadeh Mohammad R. , Karimi Narges , Mohammadi Ali A. , Karimi Ali R.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of α‐Isocyano‐α‐alkyl(aryl)acetamides and Their Use in the Multicomponent Synthesis of 5‐Aminooxazole, Pyrrolo[3,4‐b]pyridin‐5‐one and 4,5,6,7‐Tetrahydrofuro[2,3‐c]pyridine.
Authors: Fayol Aude , Housseman Christopher , Sun Xiaowen , Janvier Pierre , Bienayme Hugues , Zhu Jieping
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
New Synthesis of Benzothiazines and Benzoisothiazoles Containing a Sulfoximine Functional Group.
Authors: Harmata Michael , et al. et al.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
One‐Pot Synthesis of Furo[3,2‐c]oxepin‐4‐one Derivatives by the CAN‐Mediated Reaction of tert‐Butyl 2‐(2‐Hydroxytetrahydrofuran‐2‐yl)acetates with Alkenes.
Authors: Kobayashi Kazuhiro , Umakoshi Hironobu , Hayashi Kazutaka , Morikawa Osamu , Konishi Hisatoshi
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Tetrahydro‐1,5‐benzoxazepines and Tetrahydro‐1H‐1,5‐benzodiazepines by a Tandem Reduction‐Reductive Amination Reaction.
Authors: Bunce Richard A. , Smith Christopher L. , Lewis Jason R.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Evaluation of C‐Trialkylsilyl Enol and Thioenol Ethers as Intermediates in the Synthesis of Acylsilanes.
Authors: Hammaecher Catherine , Ouzzane Imad , Portella Charles , Bouillon Jean‐Philippe
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Efficient Synthesis of Alkynylsilyl Ethers and Silaketals via Base‐Induced Alkynylsilane Alcoholysis.
Authors: Grimm Jonathan B. , Lee Daesung
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Nonracemic Allylic Hydroxy Phosphonates via Alkene Cross Metathesis.
Authors: He Anyu , Yan Bingli , Thanavaro Anchalee , Spilling Christopher D. , Rath Nigam P.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Diaryl Selenides Using the in situ Reagent SeCl2.
Authors: Zade Sanjio S. , Panda Snigdha , Singh Harkesh B. , Wolmershaeuser Gotthelf
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Neolignan and Megastigmane Glycosides from the Leaves of Pterospermum semisagittatum.
Authors: Khan M. S. H. , Nahar N. , Mosihuzzaman M. , Rashid M. A.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Novel Domino Reactions for Diterpene Synthesis.
Authors: Bhar Shanta S. , Ramana M. M. V.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Total Synthesis of Stevastelins B3 and C3: Structure Confirmation of Stevastelin B3 and Revision of Stevastelin C3.
Authors: Kurosawa Kazuo , Matsuura Keigo , Chida Noritaka
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
1,3:4,6‐Di‐O‐benzylidene‐D‐mannitol as a Source for Novel Chiral Intermediates Through Regioselective Reductive Cleavage.
Authors: Aravind Appu , Baskaran Sundarababu
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
A Minor Phenolic Alkaloid from Cocculus hirsutus Diels.
Authors: Yadav S. B. , Tripathi Vyasji
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Thiosugar Nucleosides. Synthesis and Biological Activity of 1,3,4‐Thiadiazole, Thiazoline and Thiourea Derivatives of 5‐Thio‐D‐Glucose.
Authors: Al‐Masoudi Najim A. , Al‐Soud Yaseen A. , Al‐Masoudi Wasfi A.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Cross Metathesis Route in Sphingomyelin Synthesis.
Authors: Hasegawa Hiroko , Yamamoto Tetsuya , Hatano Sho , Hakogi Toshikazu , Katsumura Shigeo
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
New Compounds from the Seeds of Embelia ribes Burm.
Authors: Haq K. , Ali M. , Siddiqui A. W.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
An Expedient and Short Synthesis of a 6‐Iodo Isocoumarin Building Block for the Rubromycin Family and Its First Palladium‐Catalyzed Couplings.
Authors: Brasholz Malte , Reissig Hans‐Ulrich
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
First Total Synthesis of the Brominated Polyacetylenes (+)‐Diplyne A and D: Proof of Absolute Configuration.
Authors: Gung Benjamin W. , Gibeau Craig , Jones Amanda
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Magnetic Properties of Chalcogenide Glasses
Authors: Tver'yanovich Yu. S.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Progress in High Field EPR: Inorganic Materials
Authors: Reidi Peter C. , Smith Graham
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Thermal Conductivity of Nanofluids: Vision and Key Features
Authors: Choi S. U. S.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Transition Metals in Organic Synthesis
Authors: Fairlamb Ian J. S.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthetic Methods. Part 3. Heteroatom Methods
Authors: Fletcher Matthew D.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Ruthenium‐Promoted Radical Processes Toward Fine Chemistry
Authors: Delaude Lionel , Demonceau Albert , Noels Alfred F.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Ruthenium‐Catalyzed C—C Bond Formation
Authors: Derien Sylvie , Monnier Florian , Dixneuf Pierre H.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Isocyanatopropyltrimethoxysilane: Key Intermediate of New Silane Coupling Agents
Authors: Maciejewski Hieronim , Marciniec Bogdan , Wyszpolska Agnieszka
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Complex Chemistry of Novel Di‐ and Trihydroxyoligosilanes
Authors: Hoffmann D. , Reinke H. , Krempner C.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Silylative Coupling and Cross‐Metathesis of Alkenes and Dienes with Vinyl‐Silicon Derivatives: New Catalytic Routes to Synthesis of Organosilicon Compounds
Authors: Marciniec Bogdan
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Quaternary Salts of Azaaromatics as Biological Agents and as Components of Supramolecular Systems
Authors: Dondela Barbara , Sliwa Wanda
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Heterocyclic Chemistry
Authors: Stockman R. A.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Recent Developments in Robust Microporous Porphyrin Solids
Authors: Smithenry Dennis W. , Suslick Kenneth S.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Novel Synthesis of Carbapenams Using a Palladium Catalyst
Authors: Kozawa Yuji , Mori Miwako
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Substituted m‐Terphenyls
Authors: Maeyama Katsuya , Yonezawa Noriyuki
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Substituted o‐Terphenyl via Electrophilic Aromatic Substitution and Other Routes
Authors: Maeyama Katsuya , Yonezawa Noriyuki
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
The Dynamics of Chlorine‐Atom Reactions with Polyatomic Organic Molecules
Authors: Murray Craig , Orr‐Ewing Andrew J.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Study on the Ability of Chloroisocyanuric Derivatives to Generate Chloramines, Alone or in Presence of Nitrogen‐Containing Compounds
Authors: Paul Jean‐Michel , Hecquet Gerard , Mieloszynski Jean‐Luc
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Oxidation of Organic Compounds by Ruthenium Tetraoxide
Authors: Sica Donato
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Solvent Free Oxidations Using Manganese Dioxide, Barium Manganate and Potassium Permanganate
Authors: Shaabani Ahmad , Lee Donald G.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Optical Excitations in Organic Dendrimers Investigated by Time‐Resolved and Nonlinear Optical Spectroscopy
Authors: Goodson T. G. III
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Multiscaling comparative analysis of time series and geophysical phenomena
Authors: Scafetta Nicola , West Bruce J.
Published: April 2005

Different methods are used to determine the scaling exponents associated with a time series describing a complex dynamical process, such as those observed in geophysical systems. Many of these methods are based on the numerical evaluation of the variance of a diffusion process whose step increments are generated by the data. An alternative method focuses on the direct evaluation of the scaling coefficient of the Shannon entropy of the same diffusion distribution. The combined use of these methods can efficiently distinguish between fractal Gaussian and Lévy‐walk time series and help to discern between alternative underling complex dynamics. © 2005 Wiley Periodicals, Inc. Complexity 10: 51–56, 2005
Attenuated gastropathy but not enteropathy of diclofenac–cholestyramine complex in rats
Authors: Ramírez‐Alcántara Verónica , Castañeda‐Hernández Gilberto , Alan Rampy Bill , Aronson Judith F. , Treinen‐Moslen Mary
Published: April 2005

Diclofenac is a nonsteroidal anti‐inflammatory drug (NSAID) widely prescribed for pain and inflammation. Theoretically, the gastrointestinal (GI) complications of diclofenac could be minimized by administering a diclofenac resinate formulation, such as Flotac, where GI mucosal contact with free NSAID is minimized by its complexing with the cholestyramine resin. The objective of the present study was to investigate the influence of cholestyramine co‐treatment on diclofenac enteropathy in fed rats and diclofenac gastropathy in fasted rats. Male Sprague‐Dawley rats were gavaged with diclofenac (50 mg/kg), diclofenac (50 mg/kg) plus cholestyramine (50 mg/kg), or an equivalent amount of Flotac, a 1:1 wt/wt mixture of diclofenac and cholestyramine presently used in human therapeutics in Mexico. Ulceration of the GI tract, serum proteins, and bile salts were assessed at 3, 12, or 24 h. Cholestyramine alone produced no detectable alterations in small intestinal integrity or serum bile salts levels. Fed rats given Flotac or diclofenac plus cholestyramine showed patterns of small intestinal ulceration and serum protein decline that were similar to rats given only diclofenac. Thus, no influence on enteropathy was detected. In contrast, fasted rats given Flotac showed a modest reduction in the number and length of gastric lesions compared to rats given diclofenac. The observed attenuation of gastric lesions with Flotac is consistent with a role for direct cytotoxicity in NSAID gastropathy. Drug Dev. Res. 64:19–27, 2005. © 2005 Wiley‐Liss, Inc.
Design of new potent hypolipidemic agents with the synergistic structural properties of α‐asarone and fibrates
Authors: Zúñiga Clara , Garduño Leticia , del Carmen Cruz María , Salazar María , Pérez‐Pastén Ricardo , Chamorro Germán , Labarrios Fernando , Tamariz Joaquín
Published: April 2005

The series of bioisosteric analogs 9–17 were designed based on the potential pharmacophores of the highly hypolipidemic agents, α‐asarone (1), and fibrates such as clofibrate (2) and fenofibrate (3). These compounds are characterized by their simplicity, in terms of functional group diversity, because most of them are phenoxyacetic acids or their methyl and ethyl esters monosubstituted by an ethyl side‐chain at the ortho, meta, and para positions of the benzene ring. Despite this structural simplicity, these derivatives exhibited potent hypocholesterolemic activity, lowering the mice serum cholesterol and low‐density lipoprotein cholesterol levels up to 40% at the lowest dose of 25 mg/kg. These results supported the concept that the phenoxyacetic frame and the ethyl side‐chain can be considered as potent pharmacophores for the preparation of potential hypocholesterolemic drugs. Drug Dev. Res. 64:28–40, 2005. © 2005 Wiley‐Liss, Inc.
Poly(Arylene Ether Sulfone) Copolymers and Related Systems from Disulfonated Monomer Building Blocks: Synthesis, Characterization, and Performance – A Topical Review
Authors: Harrison W. L. , Hickner M. A. , Kim Y. S. , McGrath J. E.
Published: April 2005

Research and development efforts have been focussed over the last five years towards the preparation of new, but potentially commercially viable low‐cost copolymers for use as proton exchange membrane for fuel cell and other membrane applications.

Our primary efforts centered on the direct synthesis of disulfonated copolymersviastep‐polycondensation methods. These novel series of disulfonated copolymers include optionally fluorinated poly(arylene ethers), poly(thioethers), polyimides, polybenzimidazoles, and polybenzoxazoles, as well as multiblock copolymer systems. The first generation of alternative proton exchange membranes (PEMs) has focused on wholly aromatic, disulfonated poly(arylene ether sulfone) random copolymers. Detailed herein are the development and current state of these disulfonated poly(arylene ether sulfone) copolymers and their fuel cell performance in both hydrogen‐air PEMFCs and direct methanol fuel cells (DMFC).
Selenium‐Containing Heterocycles from Isoselenocyanates: Cycloaddition of Carbodiimides to Selenazetidines
Authors: Sommen Geoffroy L. , Linden Anthony , Heimgartner Heinz
Published: April 2005

The reactions of isoselenocyanates with carbodiimides in refluxing hexane afforded 1,3‐selenazetidine‐2,4‐diimines 3a–3h by a [2+2] cycloaddition in moderate‐to‐good yields. The molecular structure of 3a has been established by X‐ray crystallography.
Theoretical Study of the Alkaline Hydrolysis of Tricyclic Carbapenem
Authors: Fasoli Hector J. , Frau Juan
Published: April 2005

Alkaline hydrolysis is a good test to evaluate the properties of β‐lactam compounds and derivatives. In this work, a RHF/6‐31+G*//RHF/6‐31+G* theoretical study of the mechanism controlling the alkaline hydrolysis of sanfetrinem was conducted. The geometric properties of this compound are consistent with an intrinsic reactivity similar to that of other β‐lactams including penicillins and cephalosporins. Also, similarly to cephalosporins, the MeO group provides an alternative route for the hydrolysis mechanism.
Formation and Dissociation of Tetrahedral Nickel(II) and Cobalt(II) Complexes of ‘Dithioimidodiphosphato’ Ligands, Measurement of Kinetically Determined Stability Constants, and Kinetic Investigations of the Rapid Formation of Tetrahedral Bis(ligand)copper(II) Complexes and Their Rates of Reduction to Trinuclear Copper(I) Species
Authors: Moore Peter , Errington William , Sangha Satindra P.
Published: April 2005

The stopped‐flow technique was used to measure the rates of formation and dissociation of tetrahedral [ML2] complexes (M2+=Ni2+or Co2+) of four bidentate S2‐donor ‘dithioimidodiphosphato’ ligands L−(HL=[R1R2P(S)]NH[P(S)R3R4], R1to R4=alkyl) at 25.0° in MeOH/H2O 95 : 5 (v/v) solution and in the presence of either MOPS (=3‐(morpholin‐4‐yl)propane‐1‐sulfonic acid) or 2,6‐lutidine (=2,6‐dimethylpyridine) buffers. The kinetically determined equilibrium formation constants for [ML]+ions (M=Ni or Co) are 10−5 K=0.50±0.01 or 1.64±0.07 l mol−1for L=L3(R1=R2=Me(CH2)2CH(Me), R3=R4=Me2CH), 1.27±0.02 or 7.93±0.09 l mol−1for L=L7(R1to R4=Me2CHCH2), 0.88±0.04 or 3.84±0.13 l mol−1for L=L8(R1to R4=Me2CH), and in case of Ni2+1.88±0.04 l mol−1for L=L6(R1=R3=Bu, R2=R4=tBu) (seeTable 3; for L3and L6–L8, seeTable 1). Whereas the tetrahedral Ni2+complexes dissociate more slowly than the analogous Co2+species, in all cases, the Co2+complexes are more stable than those of Ni2+due to their larger formation rate constants (Table 3). Reactions of Cu2+with eight ligands HL (R1to R4=alkyl, alkoxy, aryl, and aryloxy) show that formation of intensely colored tetrahedral [CuIIL2] species is too fast be measured with the available stopped‐flow apparatus (t1/2<2 ms), but the subsequent rates of reduction of [CuIIL2] to give trinuclear products [CuI3L3] are measurable. An X‐ray analysis establishes the structure of one of the [Cu3L3] complexes, where R1=R2=Me2CHO and R3=R4=2‐(tert‐butyl)phenyl (L=L5), and a multiwavelength stopped‐flow kinetic experiment establishes the spectrum of a tetrahedral [CuIIL2] species prior to the reduction reactions. The redox reactions proceed at 25.0° with first‐order rate constants in the range 0.285 s−1(R1to R4=PhO; L=L11) to 2.58⋅10−4 s−1(R1to R4=Me2CHCH2; L=L7) (Table 4).
Functionalization of the 6,14‐Bridge of the Orvinols
Authors: Chen Weibin , Parrish Damon A. , Deschamps Jeffrey R. , Coop Andrew
Published: April 2005

The anion 5 of thebaine (1) reacts with small electrophiles exclusively at the 5‐position (Scheme 1). Reaction of thebaine anion with a range of alkylarylsilyl chlorides showed that reaction at the 7‐position was favored with increasing steric bulk, with triphenylsilyl chloride yielding only the 7‐substituted product 7e (Scheme 1). Reaction of 7‐(triphenylsilyl)thebaine (7e) with benzoquinone gave rise to the expected Diels–Alder adduct 8 (Scheme 2), an analog of thevinone (2) with a silyl substituent at the 6,14‐etheno bridge. The presence of this substituent gives a handle for potentially functionalizing the bridge of this important class of compounds.
A comparison of MODIS and NOHRSC snow‐cover products for simulating streamflow using the Snowmelt Runoff Model
Authors: Lee Songweon , Klein Andrew G. , Over Thomas M.
Published: April 2005

Remote sensing is an important source of snow‐cover extent for input into the Snowmelt Runoff Model (SRM) and other snowmelt models. Since February 2000, daily global snow‐cover maps have been produced from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS). The usefulness of this snow‐cover product for streamflow prediction is assessed by comparing SRM simulated streamflow using the MODIS snow‐cover product with streamflow simulated using snow maps from the National Operational Hydrologic Remote Sensing Center (NOHRSC). Simulations were conducted for two tributary watersheds of the Upper Rio Grande basin during the 2001 snowmelt season using representative SRM parameter values. Snow depletion curves developed from MODIS and NOHRSC snow maps were generally comparable in both watersheds: satisfactory streamflow simulations were obtained using both snow‐cover products in larger watershed (volume difference: MODIS, 2·6%; NOHRSC, 14·0%) and less satisfactory streamflow simulations in smaller watershed (volume difference: MODIS, −33·1%; NOHRSC, −18·6%). The snow water equivalent (SWE) on 1 April in the third zone of each basin was computed using the modified depletion curve produced by the SRM and was compared within situSWE measured at Snowpack Telemetry sites located in the third zone of each basin. The SRM‐calculated SWEs using both snow products agree with the measured SWEs in both watersheds. Based on these results, the MODIS snow‐cover product appears to be of sufficient quality for streamflow prediction using the SRM in the snowmelt‐dominated basins. Copyright © 2005 John Wiley & Sons, Ltd.
Hydration process as an activation of trans‐ and cisplatin complexes in anticancer treatment. DFT and ab initio computational study of thermodynamic and kinetic parameters
Authors: Burda Jaroslav V. , Zeizinger Michal , Leszczynski Jerzy
Published: April 2005

The thermodynamic and kinetic aspects of hydration reactions of cis‐/transplatin were explored. The polarizable continuum model was used for estimation of solvent effects. Using the B3LYP/6‐31+G(d) method, the structures were optimized and vibrational frequencies estimated. Interaction energies and activation barriers were determined at the CCSD(T)/6‐31++G(d,p) level within the COSMO approach. An associative mechanism was assumed with a trigonal‐bipyramidal structure of the transition state. Within the applied model, all the hydration reactions are slightly endothermic. The Gibbs energies of cisplatin hydration amount to 7.0 and 14.2 kcal/mol for the chloride and ammonium replacement, respectively. Analogous values for the transplatin reactions are 6.8 and 11.9 kcal/mol. The determined rate constants are by several (three to four) orders of magnitude larger for the dechlorination process than for deammination. The cisplatin dechlorination rate constant was established as 1.3 · 10−4 s−1 in excellent accord with the experiment. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 907–914, 2005
Capillary electrochromatographic chiral separations with potential for pharmaceutical analysis
Authors: Mangelings Debby , Maftouh Mohamed , Vander Heyden Yvan
Published: April 2005

The use of capillary electrochromatography as a chiral separation technique for pharmaceutical applications is reviewed. Publications of the past 10 years that provide a potential practical application in pharmaceutical analysis are considered. Method development or validation, separation strategies, and potential routine analysis by the methods/applications cited are the main subjects on which we focused our attention. The indirect chiral separation method was only used once in CEC mode. In the direct chiral separations, the use of chiral stationary phases was obviously preferred over the use of chiral mobile phases with non‐chiral stationary phases. Amongst the chiral stationary phases, those based on macrocyclic antibiotics and polysaccharide selectors were the most frequently used. Monolithic stationary phases also have several applications, but not so extended as those with packed capillary electrochromatography. The considered papers not only describe the applicability of the technique for relatively large sets of chiral analytes, they also showed that various types of stationary phases can be produced in‐house in a simple manner. However, to survive as a mature separation technique, considerable time and effort are still needed to solve some disadvantages currently characterizing capillary electrochromatography.
Capillary electrochromatography using polyelectrolyte multilayer coatings
Authors: Kamande Mary W. , Fletcher Kristin A. , Lowry Mark , Warner Isiah M.
Published: April 2005

This review covers recent progress in polyelectrolyte multilayer (PEM) coatings applied to analytical separations using open‐tubular capillary electrochromatography (OT‐CEC). The simple preparation procedure involved in the PEM approach has provided some attractive features over other modes of capillary electrophoresis‐based separations including packed column capillary electrochromatography (PC‐CEC) and micellar electrokinetic chromatography (MEKC). PEM coatings have been used to alleviate the adsorption of basic analytes, to improve separations, and to improve the stability of the electroosmotic flow. Fundamental aspects of PEM coatings on surfaces and analytical separation platforms are briefly outlined in this review. In addition, applications of PEM coatings to fused‐silica capillaries or microchip separation devices for the separation of small achiral or chiral analytes, as well as large biomolecules, are discussed.
Study on the Gelation of a No‐Flow Underfill Through Monte Carlo Simulation
Authors: Zhang Zhuqing , Yamashita Tsuyoshi , Wong Ching P.
Published: April 2005

Summary: The gelation behavior of an epoxy/anhydride system was studied using the differential scanning calorimeter (DSC) and a stress rheometer. It was found that the gelation was dependent on the curing temperature. At a higher curing temperature, the resin tended to gel at lower degree of cure (DOC). Monte Carlo (MC) simulation was performed, to investigate the effect of curing kinetics on the network formation and the gelation. Both the effects of the propagation rate and the catalyst concentration was studied. The temperature dependent gelation was related to the change of propagation/initiation ratio with temperature according to the simulation results.

Reaction mechanism of the epoxy/anhydride curing.

magnified image

Reaction mechanism of the epoxy/anhydride curing.
Acrylic‐Based Polyurethane/Silica Hybrids Prepared by Acid‐Catalyzed Sol–Gel Process: Structure and Mechanical Properties
Authors: Chen Guodong , Zhou Shuxue , Gu Guangxin , Wu Limin
Published: April 2005

Summary: Silica sols were first prepared based on different ratios of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) by an acid‐catalyzed sol–gel process, and then incorporated into acrylic‐based polyurethanes. The structures and morphologies of silicone‐oxo clusters were studied by 29Si NMR, SAXS, and scanning electron microscopy (SEM), whereas the mechanical properties of polyurethane/silica hybrids were characterized by DMA and tensile tests. The silicone‐oxo clusters in both silica sol and polyurethane hybrids became denser and larger at a higher molar ratio of TEOS/MTES and higher silica content, and the silica‐oxo clusters of polyurethane/silica hybrids even became more compact and larger than those of silica sols, increasing the elastic modulus and tensile strength of polyurethane/silica hybrids.

Typical structure of silica sol prepared from the hydrolysis and condensation of TEOS and MTES with acid as the catalyst.

magnified image

Typical structure of silica sol prepared from the hydrolysis and condensation of TEOS and MTES with acid as the catalyst.
Influence of Addition of Organoclays on Morphologies in Nylon 6/LLDPE Blends
Authors: Yoo Youngjae , Park Changhyun , Lee Sung‐Goo , Choi Kil‐Yeong , Kim Dae Su , Lee Jae Heung
Published: April 2005

Summary: Polymer blend nanocomposites containing linear low density polyethylene (LLDPE), nylon 6 and organoclays were prepared by melt mixing, and their morphologies and structures were examined with a field emission scanning electron microscope (FE‐SEM) and an X‐ray diffractometer (XRD). The size of phase‐separated domains decreased considerably with increasing content of organoclay. The d‐spacing of organoclay in the nanocomposites was increased from about 18.6 to over 28 Å. This effect was highly dependent on nylon 6 contents because nylon 6 is more polar and shows higher affinity to the organoclays compared to LLDPE.

magnified image
Quantitative Analysis of Compositional Distribution in Biodegradable Poly(ethylene oxide)/Poly(3‐hydroxybutyrate) Blend Film with Compositional Gradient by FT‐IR Microspectroscopy
Authors: Zhao Li , He Yong , Inoue Yoshio
Published: April 2005

Summary: FT‐IR microspectroscopy was used to map the compositional distribution along the cross‐section on the gradient films of fully biodegradable poly(ethylene oxide) (PEO)/poly(3‐hydroxybutyrate) (PHB) blend system. First, a linear fitting line for a calibration, related the absorbance ratio of two peaks to the fraction of PEO in the blend, was established. During linear fitting, a new equation was deduced and the influence of the different crystallinities on the absorption peaks at the wavenumber 962 and 1 342 cm−1 for PEO, 980 and 1 380 cm−1 for PHB, have been taken into account. For the PEO/PHB blend system, it was found that the crystallinity has little effect on the absorbance ratios of A962/A1 380 and A1 342/A1 380. Based on the results from the linear fitting, which comes from the relation of the absorbance ratios of A962/A1 380 or A1 342/A1 380 and the combination of the weight fraction of PEO (WPEO/(1 − WPEO)), the compositional distributions on the cross‐section of three kinds of compositional gradient films of the PEO/PHB blend prepared by different technologies have been successfully estimated. Furthermore, the better method for preparing the PEO/PHB blend film with compositional gradient was found based on the result of the quantitative analysis of the compositional distribution.

The compositional distribution along the cross‐section of the gradient films based on PEO/PHB binary system for the Type I gradient film.

magnified image

The compositional distribution along the cross‐section of the gradient films based on PEO/PHB binary system for the Type I gradient film.
Reliability of spatiotemporal gait outcome measures in Huntington's disease
Authors: Rao Ashwini K. , Quinn Lori , Marder Karen S.
Published: April 2005

Gait impairments are very important in Huntington's disease (HD), because loss of independence in gait is an important predictor of nursing home placement. Given this importance, it is imperative to test reliable and sensitive outcome measures that can be tested easily in various clinical environments. Here, we examined the test–retest reliability of gait outcome measures using the GAITRite instrumented carpet. We tested 12 subjects with HD and 12 age‐matched controls in two separate sessions. At each session, subjects walked across the GAITRite carpet at a comfortable speed. We used the intraclass correlation coefficient (ICC) and coefficient of variation (CoV) to measure test–retest reliability. Reliability was very high for all outcome measures (velocity, cycle time, stride length, cadence, and base of support), as seen by high ICC scores (0.86 to 0.95) and low CoV scores (0.042–0.102). In addition, the performance across the two subject groups was very different, indicating that the GAITRite is sensitive enough to distinguish between populations. Given that the GAITRite is a relatively inexpensive and portable piece of equipment, it can be used in a wide variety of clinical settings and clinical trials. Our data on high test–retest reliability and sensitivity extends the utility of the GAITRite to the HD population. © 2005 Movement Disorder Society
Effects of dietary fiber on inflammatory bowel disease
Authors: Galvez Julio , Rodríguez‐Cabezas M. Elena , Zarzuelo Antonio
Published: April 2005

The chronic idiopathic inflammatory bowel diseases (IBDs), namely Crohn's disease and ulcerative colitis, appear to be derived from an inappropriate reaction towards a luminal agent, most probably driven by the intestinal microflora, which upregulates the synthesis and release of different pro‐inflammatory mediators, thus contributing to tissue damage that characterizes these intestinal conditions. Several studies have reported that IBD is associated with impairment in short‐chain fatty acid (SCFA) production, mainly acetate, propionate, and butyrate. They are produced in the large bowel by anaerobic bacterial fermentation of undigested dietary carbohydrates and fiber polysaccharides, with butyrate being considered as the major fuel source for colonocytes. These SCFAs have been proposed to play a key role in the maintenance of colonic homeostasis. Therefore, it is reasonable to consider therapeutic approaches that increase colonic SCFA production, as it can be achieved by administration of dietary fiber to IBD patients. Unfortunately, there is quite limited documentation of efficacy of dietary fiber in properly designed trials. This review discusses the rationale, available evidence for the use of dietary fiber and its mechanisms of action in the treatment and prevention of IBDs.
Complex tauto‐ and rotamerism of 2‐(R‐phenyl)‐1,2,3,4‐tetrahydroquinazolines
Authors: Gawinecki Ryszard , Kolehmainen Erkki , Kuczek Agnieszka , Pihlaja Kalevi , Ośmiałowski Borys
Published: April 2005

Detailed NMR spectral analysis of CDCl3 solutions of 2‐(R‐phenyl)‐1,2,3,4‐tetrahydroquinazolines reveals three or four tautomeric forms. Apart from 2‐[(benzylideneamino)methyl]aniline, the other chain tautomeric forms are present only in minor quantities. In general, electron‐donating substituents increase the contribution of all chain forms. Lowering the temperature of the CDCl3 solution of 2‐(R‐phenyl)‐1,2,3,4‐tetrahydroquinazolines decreases the content of the 2‐[(benzylideneamino)methyl]aniline form. At the same time, the amount of the ring form increases. Opening of the tetrahydropyrimidine ring in 2‐(R‐phenyl)‐1,2,3,4‐tetrahydroquinazolines was found to be an endothermic process especially for less electron‐donating substituents. Copyright © 2005 John Wiley & Sons, Ltd.
Kinetics and mechanism of oxime formation from methyl benzoylformate
Authors: Malpica A. , Calzadilla M.
Published: April 2005

Rate and equilibrium constants for methyl benzoylformate oxime formation were determined as a function of pH over the range from about 0 to 6. The reaction occurs with rate‐determining carbinolamine dehydration over the entire range of pH investigated. Specific acid catalysis is dominant at pH < 4. Above that value, a pH‐independent reaction becomes apparent. This early appearance of an uncatalyzed reaction is interpreted as intramolecular assistance of the ester moiety in carbinolamine dehydration. Copyright © 2005 John Wiley & Sons, Ltd.
Kinetic study of the amination of Grignard reagents and cuprates with O‐methylhydroxylamine
Authors: Erdik Ender , Eroğlu Fatma , Kâhya Didem
Published: April 2005

Substituent effects on the rate of electrophilic amination of phenylmagnesium bromides, magnesium diphenylcuprates and catalytic phenylzinc cyanocuprates with O‐methyhydroxylamine in THF were investigated in a competitive kinetic study. Rate data and Hammett substituent constants are discussed on the basis of proposed mechanisms for the substitution reactions of these organometallics with an electrophilic amino transfer reagent. Copyright © 2005 John Wiley & Sons, Ltd.