bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Structure and Reactivity of Ruthenium(II) Carbonyl Complexes Containing Bis(pyrazol‐1‐yl)methane and Bis(N‐methylimidazol‐2‐yl)methane
Authors: Messerle Barbara A. , Tolhurst Vicki‐Anne , Turner Peter 
Published: June 2004

AbstractA series of ruthenium(II) complexes with the pyrazolylalkane ligands bis(pyrazol‐1‐yl)methane (BPM) (I) and bis(3,5‐dimethylpyrazol‐1‐yl)methane (dmBPM) (II), and the imidazolylalkane ligand bis(N‐methylimidazol‐2‐yl)methane (BIM) (III) have been synthesised and characterised. The complexes [Ru(N‐N)(CO)2X2] [N‐N = BPM, X = Cl (1a), Br (1b); N‐N = dmBPM, X = Cl (2); N‐N = BIM, X = Cl (3)] were prepared from the stoichiometric reaction of [Ru(CO)2X2]n and the bidentate N‐donor ligand in refluxing methanol. The crystal structure of 2 showed the complex to have octahedral geometry about the ruthenium centre, with the carbonyl and chloride ligands being coordinated cis and trans, respectively. The complex [Ru(BPM)2(CO)(Cl)][BPh4] (4) was prepared from the reaction of RuCl3 and BPM in refluxing DMF, or from the decarbonylation of [Ru(BPM)(CO)2Cl2] (1a) in the presence of BPM and NaBPh4. The NMR spectra of 4 were fully assigned from 2D NMR experiments. The NOESY showed a cis coordination of the chloride and carbonyl ligands, and this was confirmed by single crystal X‐ray diffraction studies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Evolution of Defects in the Bulk Structure of MoO3 During the Catalytic Oxidation of Propene
Authors: Ressler Thorsten , Wienold Julia , Jentoft Rolf E. , Girgsdies Frank 
Published: June 2004

AbstractThe evolution of characteristic defects in the bulk structure of MoO3 under propene oxidation conditions was investigated by in situ X‐ray absorption spectroscopy and X‐ray diffraction. Under the reaction conditions employed (273 K to 773 K, and propene to oxygen ratios from 1:1 to 1:5), orthorhombic MoO3 remains the only crystalline phase detected by XRD. The starting temperature for the reaction of propene and oxygen in the presence of MoO3 coincides with the temperature at which reduction of MoO3 begins in He, H2 and propene (≈︁ 620 K). At temperatures below 720 K, and independent of the atmosphere used, partial reduction of MoO3 is observed resulting in the formation of “Mo18O52” type defects in the layer structure of α‐MoO3. At temperatures above 720 K, and under oxygen or in an oxidizing atmosphere, the “Mo18O52” type defects are reoxidized to MoO3. Evidently, the catalytically active molybdenum oxide phase develops under partial oxidation conditions at temperatures below 720 K, and does not possess the undisturbed ideal layer structure of orthorhombic α‐MoO3. The results presented clearly show the necessity and the potential for bulk structural investigations of heterogeneous catalysts under the reaction conditions used. The bulk structure, and particularly the type and number of defects in the material (“real” structure) considerably affect the catalytic properties. Hence, in order to rationally design a most active heterogeneous catalyst, both the structure and reactions of the surface, and the structure, defects, and reactions of the bulk need to be known in detail, and carefully considered. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Cover Picture
Authors: Mohr Fabian , Jennings Michael C. , Puddephatt Richard J. 
Published: June 2004

AbstractThe cover picture shows a self‐assembled [2]catenane, with two interpenetrating 24‐membered digold rings and with intermolecular aurophilic attractions as a key feature. Details are discussed in the article by R. J. Puddephatt et al. on p. 217 ff.
[(η6‐Cyclooctatetraene){η5‐(+)‐neomenthylcyclopentadienyl}ruthenium(II)] Hexafluorophosphate: Synthesis and Characterization of a Chiral Mixed Sandwich Complex
Authors: Zhang Xiaofeng , Prosenc Marc H. , Meyer‐Friedrichsen Timo , Heck Jürgen 
Published: June 2004

AbstractThree different {η5‐(+)‐neomenthylcyclopentadienyl}ruthenium complexes have been synthesized from (−)‐menthol: [(η6‐benzene){η5‐(+)‐neomenthylcyclopentadienyl}ruthenium(II)] hexafluorophosphate (1), [tris(acetonitrile){η5‐(+)‐neomenthylcyclopentadienyl}ruthenium(II)] hexafluorophosphate (2) and [(η6‐cyclooctatetraene){η5‐(+)‐neomenthylcyclopentadienyl}ruthenium(II)] hexafluorophosphate (3). X‐ray structural determination (space group P212121) and NMR spectroscopic studies of 3 show it exists as a single stereoisomer in both the solid and solution phase, with [α]20D = +92.5. The chiral modification of the Cp ligand induces anisochrony for all of the magnetically active nuclei of the unsubstituted COT ligand. (© Wiley‐VCH Verlag GmbH & Co KGaA, 69451 Weinheim, Germany, 2003)
Synthesis and Characterization of Lanthanide(III) Bis(guanidinate) Derivatives and the Catalytic Activity of Methyllanthanide Bis(guanidinate) Complexes for the Polymerization of ϵ‐Caprolactone and Methyl Methacrylate
Authors: Luo Yunjie , Yao Yingming , Shen Qi , Yu Kaibei , Weng Linhong 
Published: June 2004

AbstractThe synthesis and structure of new lanthanide complexes with the guanidinate ligand [(Me3Si)2NC(NiPr)2−] are described. Reaction of a THF slurry of LnCl3 with a hexane solution of [(SiMe3)2NC(NiPr)2]Li (1) in a 1:2 molar ratio afforded the new soluble organolanthanide complexes [(SiMe3)2NC(NiPr)2]Ln(μ‐Cl)2Li(THF)2 [Ln = Yb (2), Nd (3)]. Alkylation of 2 and 3 with 2 equiv. of MeLi in hexane gave [(SiMe3)2NC(NiPr)2]Ln(μ‐Me)2Li(TMEDA) [Ln = Yb (4), Nd (5)] in good yield as crystalline solids. The molecular structures of 2 and 5 were determined by single‐crystal X‐ray analysis. The lanthanide ions in these complexes display a distorted pseudo‐octahedral coordination geometry. Complexes 4 and 5 exhibited extremely high activity for the ring‐opening polymerization of ϵ‐caprolactone to give high molecular weight polymers. Complex 5 also showed good catalytic activity for the syndiotactic polymerization of methyl methacrylate. (© Wiley‐VCH Verlag GmbH & Co KGaA, 69451 Weinheim, Germany, 2002)
The Effect of Phenyl Substituents on the Activity of Some Zirconocene Photoinitiators
Authors: Polo Eleonora , Barbieri Andrea , Traverso Orazio 
Published: June 2004

AbstractIn this paper we report the synthesis of several unbridged zirconocenes, 1a−c, 2 and 5, each bearing a phenyl substituent in the 2‐position of the cyclopentadienyl ring. We also report their photochemical behaviour and we compare the results with those obtained with the corresponding unsubstituted metallocenes 3a−c and 4. Study of their electronic spectra and EPR/spin trapping experiments showed photogeneration of ligand‐ and zirconium‐centred radicals, thus making these complexes suitable as photoinitiators for radical polymerisation processes. The substitution of the hydrogen atom in the 2‐position with a phenyl group had positive effects both on the absorption coefficients, improving the light absorption efficiency, and on the reaction yields of tert‐butyl acrylate polymerisation. These results can be explained in terms of the combined effects of greater persistence of the radical in solution and/or increased efficiency of the radical in initiating the polymerisation process. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Photochromic Properties of a Spirooxazine and a Spiropyran in Alcoholic Solutions of Zirconium and Aluminium Alkoxides: Influence of the Ethyl Acetoacetate Chelating Agent on the Optical Properties
Authors: Lafuma Aurélie , Chodorowski‐Kimmes Sandrine , Quinn Francis X. , Sanchez Clément 
Published: June 2004

AbstractThe photochromism of two spiro compounds, a spiropyran and a spirooxazine, dissolved in alcoholic solutions of metal alkoxides M(OR)n (M = Zr, Al) has been studied. In the case of the aluminium alkoxide Al(OsBu)3, special photochromic behaviour is observed characteristic of complexation between the coloured form of the dyes and the aluminium. This chemical interaction induces a considerable shift in the absorption spectra and a significant retardation rate in the dark. Addition of ethyl acetoacetate, a bidentate chelate of aluminium, leads to the disappearance of this particular photochromic behaviour. (© Wiley‐VCH Verlag GmbH & Co KGaA, 69451 Weinheim, Germany, 2003)
Alkylzinc Complexes with Achiral and Chiral Monoanionic N,N,O Heteroscorpionate Ligands
Authors: Hegelmann Ina , Beck Alexander , Eichhorn Christian , Weibert Bernhard , Burzlaff Nicolai 
Published: June 2004

AbstractThe synthesis of the new chiral ligand (3,5‐di‐tertbutylpyrazol‐1‐yl)(3′,5′‐dimethylpyrazol‐1‐yl)aceticacid (bpaHtBu2,Me2) (4) has been achieved. Two different synthetic routes to its precursor 3,5‐di‐tert‐butyl‐1‐[(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)methyl]‐1H‐pyrazole (bpmtBu2,Me2) (3) are reported. Deprotonation at the methylene group, followed by reaction with carbon dioxide, yielded a racemic mixture of 4. The chemical behaviour of bis(3,5‐di‐tert‐butylpyrazol‐1‐yl)acetic acid (bdtbpzaH) (2) and the new chiral N,N,O scorpionate ligand 4 involving their coordination to zinc ions was studied. [Zn(bpatBu2,Me2)Cl] (5) was formed from a mixture of ZnCl2, 4 and base. Reaction of bis(3,5‐di‐tert‐butylpyrazol‐1‐yl)acetic acid (bdtbpzaH) (2) with Zn(CH3)2 or Zn(CH2CH3)2 gave the alkylzinc complexes [Zn(bdtbpza)(CH3)] (6) and [Zn(bdtbpza)(CH2CH3)] (7). [Zn(bpatBu2,Me2)(CH3)] (8) was obtained from a synthesis analogous to that of 6 with 4. The further reactions of 6 and 8 with acetic acid resulted in the acetato complexes [Zn(OAc)(bdtbpza)] (9) and [Zn(OAc)(bpatBu2,Me2)] (10). The chiral methyl complex 8 may serve as a precursor for structural model complexes of the active sites of zinc enzymes, such as thermolysin or carboxypeptidase A. [Zn(bpatBu2,Me2)2] (11) was formed from a side reaction. Crystal structures of 4, 5, 8 and 11 were obtained; 5 crystallised as the dimer [Zn(bpatBu2,Me2)Cl]2; 11 presents an unusual zinc binding geometry. (© Wiley‐VCH Verlag GmbH & Co KGaA, 69451 Weinheim, Germany, 2003)
New Dinuclear Palladium Phosphane Complexes Stabilised by 8‐Thiotheophylline
Authors: Romerosa Antonio , López‐Magaña Carlos , Saoud Mustapha , Mañas Sonia 
Published: June 2004

AbstractThe new purine derivatives SS‐bis‐8‐(thio)‐theophylline (8‐BTTH2) and 8‐phenylthiotheophylline (8‐PhTTH), have been synthesised and characterised by elemental analysis, mass spectrometry and standard spectroscopic measurements. Reaction of 8‐BTTH2 with cis‐[PdCl2(PPh3)2] leads to the formation of the binuclear palladium complex [Pd(PPh3)(μ‐Cl)(8‐TT)]2 (8‐TTH2 = 8‐thiotheophylline) in which PPh3‐induced cleavage of the S−S bridge takes place. This complex reacts with pyridine to give a different dimeric palladium complex, [Pd(μ‐S,N‐8‐TT)(PPh3)Py]2, in which each of the two 8‐thio‐(theophylline) anions binds two metals through the N7 and S atoms. The process leading to the palladium complex has also been elucidated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Structure, and Reactivity of a New Mononuclear Molybdenum(VI) Complex Resembling the Active Center of Molybdenum Oxotransferases
Authors: Dinda Rupam , Sengupta Parbati , Ghosh Saktiprosad , Sheldrick William S. 
Published: June 2004

AbstractThe design, synthesis, and structure determination of a pentacoordinate square‐pyramidal molybdenum(VI) complex MoO2L (where LH2 is a diacidic tridentate ONO donor ligand) is reported. The substrate binding capacity of MoO2L has been demonstrated by the formation and isolation of six‐coordinate octahedral complexes [MoO2L(B)] (where B = imidazole, 1‐methylimidazole, pyridine, or γ‐picoline) and the structures of [MoO2L(Imz)] and [MoO2L(Py)] have been solved by X‐ray crystallography. Oxo transfer of MoO2L to the substrate PPh3 has been demonstrated by the formation of MoOL and [MoOL(bipy)]. Thus, the complex MoO2L behaves as a model for the active center of oxotransfer molybdoenzymes and is of interest in bioinorganic chemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Regio‐ and Stereoselective Copper‐Catalyzed Synthesis of Vicinal Haloamino Ketones from α,β‐Unsaturated Ketones
Authors: Chen Dianjun , Timmons Cody , Chao Steven , Li Guigen 
Published: June 2004

AbstractThe regio‐ and stereoselective aminochlorination of α,β‐unsaturated ketones has been developed. The reaction was conducted with N,N‐dichloro‐p‐toluenesulfonamide (4‐TsNCl2) as the nitrogen/halogen source and CuOTf as the catalyst, at 0 °C to room temperature. This method provides an easy access to vicinal haloamino ketones, with excellent regioselectivity and up to quantitative yields. Both aromatic and aliphatic enones react well with 4‐TsNCl2 under the present system, but give opposite regioselectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of 1‐Hydroxymethylene‐1,1‐bis(phosphonic acids) from Acid Anhydrides: Preparation of a New Cyclic 1‐Acyloxymethylene‐1,1‐bis(phosphonic acid)
Authors: Guenin Erwann , Degache Estelle , Liquier Jean , Lecouvey Marc 
Published: June 2004

AbstractIn continuing with our work to find new pathways to bis(phosphonate) structures we report on their synthesis from tris(trimethylsilyl) phosphite and acid anhydride. This new synthesis allows a direct access to a 1‐hydroxymethylene‐1,1‐bis(phosphonic acid) functionalised by a carboxylic function on the side chain. Moreover, we describe the formation of an original cyclic bis(phosphonate) obtained from phthalic anhydride. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Thermal Hydrogenolysis of Nitrogen‐Containing (Hetero)arenes at Elevated Temperature and Pressure
Authors: Cieplik Mariusz K. , Louw Robert 
Published: June 2004

AbstractThe behaviour of the aromatic nitrogen derivatives pyridine P and quinoline Q − and for comparison benzonitrile and azobenzene − was studied under elevated pressure (20 to 30 bar) in a flow reactor with an atmosphere of hydrogen at temperatures ranging from 773 to 1173 K. Compounds were introduced into the reactor admixed with benzene. Efficient removal of the heteroelement was observed, accompanied by deep gasification of the carbon skeletons, at higher temperatures. P reacts much faster than benzene, while Q is a little less reactive than P. The main products were methane, hydrogen cyanide and ammonia. Mechanisms are discussed based on induced decomposition by hydrogen atoms. The facile reaction of P is explained by hydrogen abstraction to give the 2‐pyridyl radical followed by ring opening, a reaction with much better thermochemistry than that for benzene and the phenyl radical. Reaction via (partially) hydrogenated intermediates may also play a part. “Exocyclic” nitrogen − such as in benzonitrile − is readily displaced by hydrogen, while for azobenzene spontaneous fission of the rather weak C−N bond is the major rate‐ (and product‐) determining step. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Versatile Route to syn‐ and anti‐α‐Amino β‐Hydroxy Esters from β‐Keto Esters by Dynamic Kinetic Resolution with Ru‐SYNPHOS® Catalyst
Authors: Mordant Céline , Dünkelmann Pascal , Ratovelomanana‐Vidal Virginie , Genet Jean‐Pierre 
Published: June 2004

AbstractA general and practical synthesis of both syn‐ and anti‐α‐amino β‐hydroxy esters with high levels of selectivity by the use of Ru‐SYNPHOS® catalysts is reported. The key transformations include asymmetric hydrogenations of α‐N‐substituted β‐keto esters protected as α‐amido or α‐amino hydrochloride derivatives, respectively. The RuII‐catalyzed hydrogenation of α‐amino β‐keto ester hydrochlorides affords the corresponding anti‐α‐amino β‐hydroxy esters with high diastereoselectivities (up to 99%) and enantioselectivities (up to 97%) through dynamic kinetic resolution (DKR). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Chemical Fixation of Carbon Dioxide Co‐Catalyzed by a Combination of Schiff Bases or Phenols and Organic Bases
Authors: Shen Yu‐Mei , Duan Wei‐Liang , Shi Min 
Published: June 2004

AbstractBinaphthyldiamino, ethyldiamino and cyclohexyldiamino Schiff bases can catalyze the reaction of epoxides with carbon dioxide in the presence of catalytic amounts of various organic bases to give the corresponding cyclic carbonates in high yields. The simplest binaphthyldiamino Schiff base, derived from the reaction of binaphthyldiamine with salicylaldehyde, gave the highest yield of cyclic carbonate. This catalytic system can be further simplified by use of a phenol instead of the Schiff base to give the corresponding cyclic carbonates in high yields as well. Mechanistic insights were obtained based on a deuterium labeling experiment. The reaction of aziridines with CO2 and epoxide with CS2 were also examined under the same reaction conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Diastereoselective Radical Tandem Addition‐Cyclization Reactions of Aromatic Tertiary Amines by Semiconductor‐Sensitized Photochemical Electron Transfer
Authors: Marinković Siniša , Hoffmann Norbert 
Published: June 2004

AbstractThe diastereoselective radical tandem addition‐cyclization reaction ofN,N‐dimethylaniline (2) with menthyloxyfuranone1was initiated by photochemically induced electron transfer using inorganic semiconductors (TiO2, ZnS, SiC and SnO2) as sensitizers. The rearomatization step, which also causes the partial reduction of1, was studied by isotopic labeling experiments using deuterated derivatives of2. The influence of the semiconductor surface on these processes has been characterized and compared with the results obtained under homogeneous conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Tandem Cleavage of Hydrogenated β‐ and γ‐Carbolines − New Practical Synthesis of Tetrahydroazocino[4,5‐b]indoles and Tetrahydroazocino[5,4‐b]indoles Showing Acetylcholinesterase Inhibitory Activity
Authors: Voskressensky Leonid G. , Borisova Tatiana N. , Kulikova Larisa N. , Varlamov Alexej V. , Catto Marco , Altomare Cosimo , Carotti Angelo 
Published: June 2004

AbstractHydrogenated γ‐carbolines underwent tandem piperidine ring cleavage on treatment with dimethyl acetylenedicarboxylate (DMAD) or ethyl propiolate (EP) in the presence of alcohols, producing 3‐alkoxymethyl‐substituted indoles in high yields. These compounds were cyclized to tetrahydroazocino[4,5‐b]indoles in the presence of AlCl3. Hydrogenated β‐carbolines produced tetrahydroazocino[5,4‐b]indoles directly upon treatment with EP in ethanol. The resulting azocinoindole derivatives were subjected to a preliminary evaluation of their in vitro acetylcholinesterase (AChE) inhibitory activities. Most of them were found to inhibit AChE with IC50 values in the micromolar range, compound 17 being the most potent (IC50 = 8.7 μM). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Catalytic Cyclopropanation of Fluorine‐Containing Alkenes and Dienes with Diazomethane and Methyl Diazoacetate
Authors: Guseva Ekaterina V. , Volchkov Nikolay V. , Tomilov Yury V. , Nefedov Oleg M. 
Published: June 2004

AbstractThe reactivities of various double bonds in fluorine‐containing unsaturated compounds toward cyclopropanation with diazomethane and methyl diazoacetate with catalysis by copper, rhodium and palladium compounds were studied. In general, the presence of fluorine atoms attached to the double bond or arranged at neighbouring positions exerted a suppressive effect on the cyclopropanation of this bond. As would be expected, diazomethane in the presence of palladium compounds primarily cyclopropanated less highly substituted double bonds. In the case of 2‐fluoro‐3‐methylbutadiene, the reaction took place at both of the double bonds. When methyl diazoacetate was used, [Rh2(OAc)4] was an efficient catalyst, yielding cyclopropanation products on monofluoro‐substituted double bonds in alkenes and cycloalkenes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Fluorinated β‐Diketones in Reactions with Diazocyclopropane Generated in situ
Authors: Tomilov Yury V. , Guseva Ekaterina V. , Kostuchenko Irina V. , Ugrak Bogdan I. , Shulishov Evgeny V. , Nefedov Oleg M. 
Published: June 2004

AbstractTreatment of 1,1‐di‐ and 1,1,1‐trifluoroalkane‐2,4‐diones 10−13 with cyclopropyldiazonium intermediates 2 and 3, generated in situ through the decomposition of N‐cyclopropyl‐N‐nitrosourea 1 by treatment with moist K2CO3, did not result in the expected azo coupling of the cyclopropyldiazonium ion, but afforded the corresponding oxaspiropentanes 14−17 as products of the addition of diazocyclopropane (3) onto one of the carbonyl groups. In addition, the reaction proceeded selectively on the carbonyl groups adjacent to the di‐ or trifluoromethyl substituents. 1,1‐Difluoroacetone reacted analogously with diazocyclopropane (3) generated in situ, giving stable 2‐(difluoromethyl)‐2‐methyloxaspiropentane in approximately 50% yield. The resulting oxaspiropentanes 14−17, on heating or in the presence of lithium iodide, rearranged selectively into cyclobutanones 20−23, while in the presence of Al2O3 they formed mixtures of approximately equal amounts of the corresponding cyclobutanones and the 1‐vinylcyclopropanols 24−27. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Galactosylated 5‐Hydroxylysine Mimetics for Glycopeptide Synthesis
Authors: Marin Julien , Violette Aude , Briand Jean‐Paul , Guichard Gilles 
Published: June 2004

AbstractThe design and synthesis of four galactosylated 5‐hydroxylysine mimetic building blocks (2−5), conveniently protected for solid‐phase glycopeptide synthesis, is described. Our approach features: i) a short and divergent route to the corresponding protected amino acid aglycons 6−9 that involves selective ring‐opening of enantiopure 5‐hydroxylated 6‐oxo‐1,2‐piperidinedicarboxylate 10 and 11 with sodium borohydride in ethanol with formation of the corresponding 1,2‐diol; ii) a common δ‐lactam precursor 12, readily accessible from Boc‐Asp‐OtBu (3 steps, 74% yield), that can be hydroxylated with a high level of asymmetric induction; iii) the use of tetra‐pivaloylated galactosyl bromide as galactosyl donor to avoid or limit orthoester formation. The four galactosylated hydroxylysine analogues 2−5 are suitable building blocks for incorporation into immunodominant peptides derived from type II collagen (CII) and for future investigations aimed at determining the fine specificity of arthritogenic T‐cells in collagen‐induced arthritis (CIA), a mouse model for rheumatoid arthritis (RA). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
New Chiral 1,2‐Diamines and Their Use in Zinc‐Catalyzed Asymmetric Hydrosilylation of Acetophenone
Authors: Bette Virginie , Mortreux André , Ferioli Federico , Martelli Gianluca , Savoia Diego , Carpentier Jean‐François 
Published: June 2004

AbstractThe preparation of two new series of chiral 1,2‐diamines and their use in the [ZnR2‐diamine]‐catalyzed asymmetric hydrosilylation of acetophenone with poly(methylhydrosiloxane) (PMHS) in an aprotic medium is reported. The effect of structural modifications of the secondary diamine ligand, in particular a possible cooperative effect of two different types of chiral centers, on the N‐benzylic side‐arms and on the ethylene bridge of the diamine skeleton, has been investigated. A new diamine ligand giving up to 91% ee is described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)