bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Structure and Characterization of New Olivacine Derivatives and Their Platinum(II) Complexes
Authors: Romaniewska Anna , Jasztold‐Howorko Ryszard , Regiec Andrzej , Lis Tadeusz , Kuduk‐Jaworska Janina 
Published: November 2003

AbstractThree unknown olivacine derivatives (L‐OCH3,L‐OH,L‐OAc) were synthesized according to a procedure that involves only a few steps, and used as ligands in the synthesis of neutral chelate platinum(II) complexes. The ligands, as well as their platinum complexes were spectroscopically characterized with IR,1H/13C NMR and UV/Vis spectroscopic techniques. The solid state structures of two ligands (L‐OCH3,L‐OAc) and one complex {[(L‐OCH3)PtCl2]} were determined by X‐ray diffraction. Molecular structure analysis of the ligands and the complex indicated that complexation resulted in a change in the conformation of the bipyridine fragment of the compounds studied and caused other interesting effects. Two crystallographically independent molecules of the complex were revealed in the measured crystal, with short intramolecular H···H distances. The structural and energetic aspects of the conformational behavior of the ligandL‐OCH3and the complex [(L‐OCH3)PtCl2] have been analyzed using semiempirical PM3 methods. In vitro antiproliferative activity was preliminarily estimated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
New [Ru3(CO)12]‐Based Catalysts with Imidazolinium Salt, Diimine, or Bis(oxazoline) Ligands and Ruthenium Bis(oxazoline) Complex for Tandem Isomerisation/Claisen Rearrangement of Dienyl Ethers − X‐ray Structure of [RuCl{(R,R)‐bis(isopropyloxazoline)}(p‐cymene)]BF4
Authors: Ben Ammar Hamed , Le Nôtre Jérôme , Salem Mansour , Kaddachi Mohamed T. , Toupet Loïc , Renaud Jean‐Luc , Bruneau Christian , Dixneuf Pierre H. 
Published: November 2003

AbstractThe reaction of various 1,7‐dienes in the presence of the three‐component catalyst A: [Ru3(CO)12]/imidazolinium salt/Cs2CO3 (1:1:2) leads to the tandem alkene isomerisation/Claisen rearrangement affording γ,δ‐unsaturated aldehydes. Other three component catalysts: [Ru3(CO)12]/diimine/Cs2CO3 and [Ru3(CO)12]/benzoxazoline or chiral bis(oxazoline)/Cs2CO3 offer new active catalytic systems for these tandem reactions. Two ruthenium complexes containing optically active bis(oxazoline), [RuCl{(R,R)‐bis(oxazoline)}(p‐cymene)]BF4, were prepared and the X‐ray structure of one of them (18) was established. The combination of chiral 18/imidazolinium salt/Cs2CO3 (1:1:2) catalysed the above reaction of 1,6‐dienes and the results suggest initial catalytic isomerisation followed by a thermal Claisen rearrangement. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
New AgI Organometallic Coordination Polymers and MII (M = CuII and CoII) Inorganic Supramolecular Complexes Generated from New Fulvene‐Type Ligands
Authors: Dong Yu‐Bin , Zhao Xia , Jin Guo‐Xia , Huang Ru‐Qi , Smith Mark D. 
Published: November 2003

AbstractTwo novel fulvene‐type organic ligands L1 and L2 have been synthesized by aroylation reaction of substituted cyclopentadienyl anions. L1 crystallized in the monoclinic space group P21, a = 6.7498(4), b = 20.5769(11), c = 8.9532(5) Å, β = 109.5060(10)°, and Z = 2. L2 crystallized in the triclinic space group P$\bar 1$
, a = 11.4126(10), b = 11.4763(10), c = 11.7719(10) Å, α = 67.050(2), β = 74.509(2), γ = 61.148(2)°, and Z = 2. The coordination chemistry of L1 and L2 has been investigated. One novel AgI‐containing organometallic coordination polymer 3, based on both AgI−C and AgI−N interactions, has been synthesized by combination of L1 and AgClO4 in a benzene/dichloromethane mixed‐solvent system. Two new MII‐containing [M = CuII (4) and CoII (5)] supramolecular complexes with seven‐membered metalla‐ring unit have been prepared by combination of L2 and the corresponding M(OAc)2·2H2O (M = CuII and CoII) salts in ethanol. The isostructural compounds 4 and 5 crystallized in the triclinic space group P$\bar 1$
[4: a = 8.8808(5), b = 10.9928(7), c = 14.2196(9) Å, α = 99.9750(10), β = 95.8190(10), γ = 93.5610(10)°, and Z = 1; 5: a = 8.7964(10), b = 10.8103(12), c = 14.3765(15) Å, α = 99.681(2), β = 95.930(2), γ = 93.429(2)°, and Z = 1]. In the solid state, molecular complexes 4 and 5 are bound by strong intermolecular N···O−H hydrogen bonds in a hand‐in‐hand fashion to give a novel one‐dimensional chain motif. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
X‐ray Crystal Structure and Electrical Conductivity of [Au(ppy)(C8H4S8)]2[PF6] [ppy− = C‐deprotonated 2‐phenylpyridine(−); C8H4S82− = 2‐{(4,5‐ethylenedithio)‐1,3‐dithiol‐2‐ylidene}‐1,3‐dithiole‐4,5‐dithionate(2−)]
Authors: Kubo Kazuya , Nakano Motohiro , Tamura Hatsue , Matsubayashi Gen‐etsu 
Published: November 2003

AbstractCrystals of [Au(ppy)(C8H4S8)]2[PF6] [ppy− = C‐deprotonated 2‐phenylpyridine(−); C8H4S82− = 2‐{(4,5‐ethylenedithio)‐1,3‐dithiol‐2‐ylidene}‐1,3‐dithiole‐4,5‐dithiolate(2−)] were prepared by current‐controlled electrolysis of a benzonitrile solution of [Au(ppy)(C8H4S8)] with [NEt4][PF6] as an electrolyte. The X‐ray crystal structure analysis revealed the formation of a columnar stacking of two crystallographically independent cations in formally the 0.5‐electron‐oxidized state. Cation moieties with some S−S non‐bonded contacts (< 3.7 Å) along the a and b axes form a two‐dimensional sheet, with the molecular interaction parallel to the ab plane. The electrical conductivities measured for a crystal at room temperature were 9.2 and 0.0028 S cm−1 along the a and c axes, respectively. From the activation energy for the electron conduction determined by the conductivities measured for a compacted pellet the complex was estimated to be metallic from room temperature to 110 K. The energy‐band calculation for the oxidized species showed two‐dimensional electron conduction through the column. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Structural, Photophysical and Chiro‐Optical Properties of Lanthanide Complexes with a Bis(benzimidazole)pyridine‐Based Chiral Ligand
Authors: Muller Gilles , Maupin Christine L. , Riehl James P. , Birkedal Henrik , Piguet Claude , Bünzli Jean‐Claude G. 
Published: November 2003

AbstractThe neutral LnIII 1:1 nitrato complexes with the chiral ligand 2,6‐bis(1‐S‐neopentylbenzimidazol‐2‐yl)pyridine (L11) have been synthesised and their stability constants measured in acetonitrile (log K1 = 4.0−6.4). The crystal and molecular structure of [Eu(NO3)3(L11)(MeCN)] shows the typical meridional planar coordination of L11 to the metal ion and low symmetry of the coordination polyhedron. The influence of the steric hindrance generated by the substituent at R2 on the crystal packing and bond lengths is discussed. Photophysical measurements show that ligand L11 induces a 3ππ*‐to‐Ln energy‐transfer process in the EuIII complex, while the TbIII compound is ten times less luminescent. Addition of a second molecule of L11 to give [Ln(ClO4)2(L11)2]+ leads to a large quenching of the EuIII luminescence (140‐fold) due to several factors: a less efficient 1ππ*⇄3ππ* transfer (ca. fourfold), a smaller intrinsic quantum yield QEu (ca. threefold), and a substantially less efficient ligand‐to‐metal transfer (ca. 12‐fold). In the case of the TbIII complex, the decrease in the energy of the triplet state reduces further the TbIII emission through increased back transfer. The specific rotary dispersion of the 1:1 and 1:2 complexes points to the chirality of the complexes arising mainly from the ligand, while the circularly polarized luminescence of these complexes with EuIII and TbIII displays a weak effect, pointing to a small diastereomeric excess in solution. Altogether, this study demonstrates that electronic, thermodynamic and photophysical properties of lanthanide complexes with aromatic terdentate ligands can be tuned by modifying the number and the arrangement of the ligands, as well as their substituents, particularly those in the R2 and R3 positions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Structure and Magnetism of a New Dodecanuclear CuII Complex with Acetato and Imidazolato Bridges, Formed by Oxidation of the Chelating Ligand 1,1,7,7‐Tetrakis(imidazol‐2‐yl)‐2,6‐diazaheptane
Authors: Song Yufei , Gamez Patrick , Stassen Arno F. , Lutz Martin , Spek Anthony L. , Reedijk Jan 
Published: November 2003

AbstractA novel dodecanuclear copper(II) complex [Cu12(tidhd)4(MeOH)8(CH3COO)8](MeOH)0.8 (Htidhd = 1,1,7,7‐tetrakis(imidazol‐2‐yl)‐2,6‐diaza‐1,6‐heptadiene) with imidazolato and acetato bridging ligands was synthesized by reaction of polyimidazole 1,1,7,7‐tetrakis(imidazol‐2‐yl)‐2,6‐diazaheptane (Htidahp) with copper acetate in a methanol solution. The complex crystallized in the triclinic space group P$\bar 1$
with a = 9.1204(1), b = 13.5139(2), c = 27.6925(5), α = 76.8006(6)°, β = 82.8066(7)°, γ = 76.4594(9)°, Z = 1. Structure analysis shows that the unit cell of the complex contains twelve copper(II) ions in three different coordination environments. The complex is centrosymmetric and the two hexanuclear units are linked by two μ3‐acetate anions [the Cu1−Cu1a distance is 3.5507(7) Å]. The magnetic superexchange interaction via the bridging imidazolate ligand appears to be the most important magnetic interaction in this complex. Magnetic susceptibility measurement vs. temperature in the range of 6−300 K were fitted to the parameters g = 2.05, Ja = −32.0 cm−1 and Jb = −5.45 cm−1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Optimization by full factorial design of the emulsifying properties of ethanol insoluble fraction from rapeseed lecithin
Authors: Sosada Marian , Pasker Beata , Gabzdyl Renata 
Published: November 2003

AbstractRapeseed lecithin ethanol insoluble fraction (LEIF), was acetylated and optimum conditions for improving LEIF emulsifying property were determined. The effects of reaction time, pyridine amount and temperature on phosphatidyl ethanolamine conversion degree (PECD) and emulsion stability index (ESI) have been described in the form of regression equations. A full factorial design method was used. Regression equations for the maximum value of response functions and computation results were calculated and compared with those obtained in control experiments. Acetylation of rapeseed LEIF with the use of calculated optimal parameters led to 35% and 60% increments in PECD and ESI, respectively.
The fatty acid composition of small and large naturally occurring milk fat globules
Authors: Briard Valérie , Leconte Nadine , Michel Françoise , Michalski Marie‐Caroline 
Published: November 2003

AbstractNative milk fat globules of various mean diameters, ranging from d43 = 1.5 to 7.3 μm, were obtained using microfiltration of raw whole milk acquired in winter and spring. After total lipid extraction, fatty acid composition was characterized by methyl and butyl ester analysis using gas chromatography. The oleic and linoleic acid content of milk obtained in winter increased with fat globule size, whereas myristic and palmitic acid decreased. There was significantly more lauric, myristic and palmitoleic acid, and less stearic acid in small fat globules compared to large fat globules in milk obtained in both winter and spring. The relative content of oleic and linoleic acids were found to depend on fat globule size and season. Results are interpreted on the basis of the relative content of milk fat globule membrane depending on fat globule size, and on consequences of compositional variations on milk fat globule melting behavior.
Determination of fatty acids and some undesirable fatty acid isomers in selected Turkish margarines
Authors: Çetin Mehmet , Yıldırım Ayhan , Şahin A. Metin 
Published: November 2003

AbstractThe fatty acid composition and total trans fatty acid content in 10 margarines produced in Turkey were determined by capillary gas chromatography and Fourier transform‐infrared spectroscopy (FT‐IR) spectroscopy. The fatty acid composition ranged as follows: saturated fatty acids, C16:0 (palmitic) 11.3 to 31.8% and C18:0 (stearic) 5.7 to 8.7%, monounsaturated fatty acids, C18:1 (oleic) 21.8 to 35.7% and C18:1 trans isomers 0.4 to 27.4%, polyunsaturated fatty acid, C18:2 linoleic acid 5.2 to 40.2%. Some positional isomers of C18:1 as cis‐11‐octadecenoic acid varied from 0.7 to 4.6% and cis‐13 trace to 2.4%. The total trans fatty acid contents were between 0.9 and 32.0% when measured with capillary gas chromatography and between 0 and 30.2% with FT‐IR spectroscopy. Some of the margarines analyzed contained trace amount of trans fatty acids which could not be detected by FT‐IR spectroscopy.
Platelet activating factor — a molecular link between atherosclerosis theories
Authors: Demopoulos Constantinos A. , Karantonis Haralabos C. , Antonopoulou Smaragdi 
Published: November 2003

AbstractThe most common causes of death in westernized societies remain heart disease and stroke. For this reason the prevention of atherosclerosis is a major objective of modern medicine. Platelet‐Activating Factor (PAF, 1‐O‐alkyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine) is a crucial mediator in the inflammatory response. PAF is synthesized by several types of cells, including platelets, monocytes, macrophages, foam cells and endothelial cells upon activation. Many experimental data reveal that atherogenic activities of oxidized LDLs can be attributed to PAF and PAF‐like lipids, which render these molecules the initiators of atherosclerosis.Several theories have been formulated for atherosclerosis. The purpose of this review is to highlight the significance of PAF and PAF‐like lipids during the early stages of atherosclerosis. Secondly to link the biological action of PAF molecules to the most accepted, current hypotheses of atherosclerosis. Thirdly to propose a mechanism for the initiation and propagation of atherosclerosis by PAF.The mechanism we propose offers a new biochemical approach and may help to explains the beneficial effects of the Mediterranean diet. Mediterranean foods contain a significant number of lipid‐like components with anti‐PAF action in vitro. The comsumption of PAF antagonist from Mediterranian foods inhibits the development of atherosclerosis. Such observations suggest that our hypothesis serves as a sound basis for further research.
Asymmetric Synthesis of (S)‐(−)‐Acromelobic Acid
Authors: Wild Nicole , Groth Ulrich 
Published: November 2003

Abstract(S)‐(−)‐Acromelobic acid (1) was synthesized in nine steps in enantiomerically pure form from citrazinic acid (4) in an overall yield of 21%. The key steps of this synthesis are the introduction of the amino function by the bis(lactim) ether method and the introduction of the acid function by Stille coupling. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Heterocyclization Reaction of α‐Imino Carbonyl Compounds − Derivatives of 2,5‐Dihydro‐1H‐imidazole Nitroxides
Authors: Roshchupkina Galina A. , Pervukhina Natalie V. , Rybalova Tatjana V. , Gatilov Yuri V. , Burdukov Alexey B. , Reznikov Vladimir A. 
Published: November 2003

Abstractα‐Imino carbonyl compounds − derivatives of 3‐imidazoline nitroxides − were found to undergo heterocyclization reactions, yielding oxazole and 1,3,5‐triazine derivatives. The most probable course of the reaction was suggested by the radioactive label method. The structures of the heterocycles synthesized were verified by X‐ray analysis of the mixed‐ligand complexes with copper hexafluoroacetylacetonate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis and Structural Characterization of meso‐Thienyl Core‐Modified Porphyrins
Authors: Gupta Iti , Hung C.‐Hsiung , Ravikanth Mangalampalli 
Published: November 2003

AbstractA series of meso‐thienyl‐substituted porphyrins with different porphyrin cores such as N3S, N2S2 and N3O were synthesized and characterized. The thienyl groups at the meso‐carbon atoms change the electronic properties of the porphyrin ring. The X‐ray structure solved for the N2S2 porphyrin with four meso‐thienyl groups showed supramolecular assembly formation in the solid state due to C−H···N hydrogen bonding between the CH group of the meso‐thienyl group of one porphyrin ring with the pyrrole N atom of another porphyrin ring. The X‐ray analysis of the N3S porphyrin with two meso‐thienyl groups and two meso‐aryl groups did not show any supramolecular assembly formation in the solid state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Acid Rearrangement of Secoiridoids Related to Oleuropein and Secologanin
Authors: Bianco Armandodoriano , Jensen Soren Rosendal , Olesen Jens , Passacantilli Pietro , Ramunno Alessia 
Published: November 2003

AbstractAcid treatment of an iridoid glycoside results in the cleavage of the acetal bond between the sugar unit and the monoterpenoid aglycon. Iridoids possessing non‐conjugated enol ether systems, however, undergo the hydration of the iridoid enol ether functionality in acid medium, as well as the hydrolysis of the bond. We examined the acid rearrangement of secoiridoids such as oleuropein (1) and secologanin (2) and their reduction products oleuropeinol (3) and secologaninol (4), to examine whether similar behaviour also occurs in this case. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Structure and Reactivity of 3,3‐Disubstituted 1‐(5‐Nitro‐2,1‐benzisothiazol‐3‐yl)triazenes
Authors: Přikryl Josef , Lyčka Antonín , Bertolasi Valerio , Holčapek Michal , Macháček Vladimír 
Published: November 2003

AbstractThe reaction between 5‐nitro‐2,1‐benzisothiazole‐3‐diazonium species and N‐substituted anilines produces the 1‐(5‐nitro‐2,1‐benzisothiazol‐3‐yl)‐3,3‐disubstituted triazenes 1. These triazenes are highly stable, and even in strongly acidic medium (0.5 mol⋅L−1 H2SO4) they are only slowly decomposed back to the diazonium ion and substituted anilinium ion (for the N‐ethyl derivative in 0.5 mol·L−1 H2SO4 at 25 °C, t1/2 ≈︁ 7 h). A series of six triazenes were characterised by their 1H and 13C NMR spectra and mass spectra. Two of the triazenes were also identified by X‐ray crystallography. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
From a Calix[4]arene to a Hexameric Supracycle
Authors: Dyker Gerald , Mastalerz Michael , Merz Klaus 
Published: November 2003

AbstractWe investigated a simple and economic method for the selective O‐arylation of calix[4]arenes with N‐heteroarenes with temperature control under neat conditions. The resulting multidentate ligands are potential building blocks for transition metal complexes or supramolecular aggregates: dipyridoxycalixarene 3b, together with palladium(II) chloride, produced a complex with a fascinating crystal structure, six molecules self‐assembling into hexameric supracycles with an outer diameter of roughly 30 Å and an inner diameter of roughly 7 Å, containing six dichloromethane molecules. The supracycles themselves are organised into hexagonal assembled tubes along the c axis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Reactions between Benzocyclobutenone Tricarbonylchromium Complexes and Lithium Dialkylphosphides: A New Route to Isochromanones
Authors: Schnebel Matthias , Weidner Ingo , Wartchow Rudolf , Butenschön Holger 
Published: November 2003

AbstractThe reaction between rac‐(benzocyclobutenone)tricarbonylchromium (rac‐1) and lithium diisopropylphosphide (LDP) or lithium di‐tert‐butylphosphide, unlike its reaction with lithium diisopropylamide (LDA), results in a distal ring‐opening, with formation of acylphosphane derivatives. The tricarbonylchromium complex rac‐6 of 2‐methylbenzoyldiisopropylphosphane has been structurally characterized. The reaction proceeds through the corresponding benzylic anion intermediate, which was shown to react with ketones or aldehydes with formation of isochromanone derivatives. This indicates that a dialkylphosphide is a much better leaving group than an amide. The availability of 1 in enantiomerically pure form inspired an inspection of the diastereoselectivity of the cyclization with aldehydes. It was found that the reaction between the intermediate and benzaldehyde took place with complete diastereoselectivity, thus establishing a route to enantiomerically pure 3‐phenylisochromanone. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Concise Total Synthesis of (+)‐Heliotridine
Authors: Pisaneschi Federica , Cordero Franca M. , Brandi Alberto 
Published: November 2003

AbstractA practical synthesis of the necine base (+)‐heliotridine (1) is reported here. The present total synthesis is based on the highly selective 1,3‐dipolar cycloaddition of (S)‐3‐tert‐butoxypyrroline N‐oxide (2) to the commercially available ethyl 4‐bromocrotonate, followed by a suitable elaboration of the adduct. The synthesis gives a 17% overall yield from nitrone 2. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
An Efficient Asymmetric Synthesis of Tarchonanthuslactone
Authors: Enders Dieter , Steinbusch Daniel 
Published: November 2003

AbstractAn efficient and straightforward ten‐step asymmetric synthesis of the polyketide tarchonanthuslactone (1) in good overall yield (21% starting from chloro lactone 5) and with excellent diastereomeric and enantiomeric excesses (de, ee ⩾ 96%) is described. The new synthetic route is based on the α,β‐unsaturated δ‐lactone building block 5, available in enantiopure form (ee > 99%) through an enzymatic procedure, and its conversion into methyl ketone 11 by an Umpolung strategy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Design of Cyclopentaisoxazoline Amino Acids as Conformationally Constrained Agonists at Glutamate Receptors
Authors: Conti Paola , De Amici Marco , Grazioso Giovanni , Roda Gabriella , Stensbøl Tine B. , Bräuner‐Osborne Hans , Madsen Ulf , Toma Lucio , De Micheli Carlo 
Published: November 2003

AbstractWe have prepared four isomeric 3‐hydroxycyclopentaisoxazoline amino acids 12−15, which represent analogues of glutamic acid having restricted conformations, through a strategy based on the 1,3‐dipolar cycloaddition of bromonitrile oxide to a suitably protected 1‐aminocyclopent‐2‐enecarboxylic acid. These target compounds proved to be inactive when assayed at ionotropic and metabotropic glutamate receptors, except for 12 which is an agonist primarily at mGluR5 (EC50 = 79 μM), but is less active at mGluR2 and only marginally active at mGluR1. The biological data are accounted for through comparison of the conformational profiles of the test compounds with that of reference agonists, i.e., N‐methyl‐D‐aspartate (NMDA, 2), and 1‐aminocyclopentane‐1,3‐dicarboxylic acids [trans‐ACPD, 10; cis‐ACPD, 11]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Use of Rhodium N‐Heterocyclic Carbene Complexes in Catalytic Cyclization and Hydrosilylation of 1,6‐Enynes to 2‐Methyl‐1‐silylmethylidene‐2‐cyclopentane
Authors: Park Kang Hyun , Kim So Yeon , Son Seung Uk , Chung Young Keun 
Published: November 2003

AbstractThe neutral rhodium complexes [RhCl(NHC)(cod)] (NHC = N‐heterocyclic carbene) catalyzed the hydrosilylation/cyclization of 1,6‐enynes and HSiR3 (R3 = Et3 and PhMe2) to form 2‐methyl‐1‐silylmethylidene‐2‐cyclopentanes in high yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Development of Thiourea‐Based Ligands for the Palladium‐Catalyzed Bis(methoxycarbonylation) of Terminal Olefins
Authors: Dai Mingji , Wang Cuihua , Dong Guangbin , Xiang Jing , Luo Tuoping , Liang Bo , Chen Jiahua , Yang Zhen 
Published: November 2003

AbstractThiourea‐based ligands were evaluated for the palladium‐catalyzed bis(methoxycarbonylation) of terminal olefins. The usefulness of these ligands for this reaction is demonstrated by their stability to oxidizing agents, and their superiority in preventing palladium precipitation and double‐bond isomerization. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)